CLARITHROMYCIN- clarithromycin tablet, film coated, extended release
A-S Medication Solutions
HIGHLIGHTS OF PRESCRIBING INFORMATION
These highlights do not include all the information needed to use CLARITHROMYCIN EXTENDED-RELEASE TABLETS safely and effectively. See full prescribing information for CLARITHROMYCIN EXTENDED-RELEASE TABLETS.
CLARITHROMYCIN Extended-release tablets, for oral use
Initial U.S. Approval: 1991
RECENT MAJOR CHANGES
INDICATIONS AND USAGE
Clarithromycin Extended-release Tablets, USP is a macrolide antimicrobial indicated for mild to moderate infections caused by designated, susceptible bacteria in the following:
Limitations of Use
To reduce the development of drug-resistant bacteria and maintain the effectiveness of Clarithromycin Extended-release Tablets, USP and other antibacterial drugs, Clarithromycin Extended-release Tablets, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. (1.4)
DOSAGE AND ADMINISTRATION
DOSAGE FORMS AND STRENGTHS
WARNINGS AND PRECAUTIONS
Most frequent adverse reactions for both adult and pediatric populations in clinical trials: abdominal pain, diarrhea, nausea, vomiting, dysgeusia (6.1)
To report SUSPECTED ADVERSE REACTIONS, contact Lannett Company, Inc. at 1-844-834-0530 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
USE IN SPECIFIC POPULATIONS
Geriatric: Increased risk of torsades de pointes(8.5)
See 17 for PATIENT COUNSELING INFORMATION.
FULL PRESCRIBING INFORMATION: CONTENTS*
5.5 All-Cause Mortality in Patients With Coronary Artery Disease 1 to 10 Years After Clarithromycin Exposure
Clarithromycin Extended-release Tablets, USP are indicated in adults for the treatment of mild to moderate infections caused by susceptible isolates due to Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis, or Streptococcus pneumoniae[see Indications and Usage (1.4)] .
Clarithromycin Extended-release Tablets, USP (in adults) are indicated for the treatment of mild to moderate infections caused by susceptible isolates due to Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae [see Indications and Usage (1.4)] .
Clarithromycin Extended-release Tablets, USP are indicated
[see Indications and Usage
for the treatment of mild to moderate infections caused by susceptible isolates due to:
Clarithromycin Extended-release Tablets, USP are indicated only for acute maxillary sinusitis, acute bacterial exacerbation of chronic bronchitis, and community-acquired pneumonia in adults. The efficacy and safety of Clarithromycin Extended-release Tablets, USP in treating other infections for which other formulations of clarothromycin are approved have not been established.
There is resistance to macrolides in certain bacterial infections caused by Streptococcus pneumoniae and Staphylococcus aureus. Susceptibility testing should be performed when clinically indicated.
To reduce the development of drug-resistant bacteria and maintain the effectiveness of Clarithromycin Extended-release Tablets, USP and other antibacterial drugs, Clarithromycin Extended-release Tablets, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
Clarithromycin Extended-release Tablets, USP should be taken with food. Swallow Clarithromycin Extended-release Tablets, USP whole; do not chew, break or crush Clarithromycin Extended-release Tablets, USP.
The recommended dosages of Clarithromycin Extended-release Tablets, USP for the treatment of mild to moderate infections in adults are listed in Table 1.
|Clarithromycin Extended-release Tablets, USP|
(every 24 hours)
|Acute bacterial exacerbation of chronic bronchitis||1 gram||7|
|Acute maxillary sinusitis||1 gram||14|
|Community-acquired pneumonia||1 gram||7|
See Table 2 for dosage adjustment in patients with moderate or severe renal impairment with or without concomitant atazanavir or ritonavir-containing regimens [see Drug Interactions (7)] .
|Recommended Clarithromycin Dosage Reduction|
|Patients with severe renal impairment (CL cr of <30 mL/min)||Reduce the dosage of clarithromycin by 50%|
|Patients with moderate renal impairment (CL cr of 30 to 60 mL/min) taking concomitant atazanavir or ritonavir-containing regimens||Reduce the dosage of clarithromycin by 50%|
|Patients with severe renal impairment (CL cr of <30 mL/min) taking concomitant atazanavir or ritonavir-containing regimens||Reduce the dosage of clarithromycin by 75%|
Decrease the dose of clarithromycin by 50 % when co-administered with atazanavir [see Drug Interactions (7)] . Dosage adjustments for other drugs when co-administered with clarithromycin may be recommended due to drug interactions [see Drug Interactions (7)] .
Clarithromycin Extended-release Tablets, USP are supplied as white or off-white, capsular-shaped film-coated 500 mg tablets debossed “S58” on one side and blank on the other side.
Clarithromycin is contraindicated in patients with a known hypersensitivity to clarithromycin, erythromycin, or any of the macrolide antibacterial drugs [see Warnings and Precautions (5.1)] .
Concomitant administration of clarithromycin with cisapride and pimozide is contraindicated [see Drug Interactions (7)] .
There have been postmarketing reports of drug interactions when clarithromycin is co-administered with cisapride or pimozide, resulting in cardiac arrhythmias (QT prolongation, ventricular tachycardia, ventricular fibrillation, and torsades de pointes) most likely due to inhibition of metabolism of these drugs by clarithromycin. Fatalities have been reported.
Clarithromycin is contraindicated in patients with a history of cholestatic jaundice or hepatic dysfunction associated with prior use of clarithromycin.
Concomitant administration of clarithromycin and colchicine is contraindicated in patients with renal or hepatic impairment.
Do not use clarithromycin concomitantly with HMG-CoA reductase inhibitors (statins) that are extensively metabolized by CYP3A4 (lovastatin or simvastatin), due to the increased risk of myopathy, including rhabdomyolysis [see Warnings and Precautions (5.4) and Drug Interactions (7)] .
Concomitant administration of clarithromycin and ergotamine or dihydroergotamine is contraindicated [see Drug Interactions (7)] .
In the event of severe acute hypersensitivity reactions, such as anaphylaxis, Stevens-Johnson Syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms (DRESS), Henoch-Schonlein purpura, and acute generalized exanthematous pustulosis, discontinue clarithromycin therapy immediately and institute appropriate treatment.
Clarithromycin has been associated with prolongation of the QT interval and infrequent cases of arrhythmia. Cases of torsades de pointes have been spontaneously reported during postmarketing surveillance in patients receiving clarithromycin. Fatalities have been reported.
Avoid clarithromycin in the following patients:
Elderly patients may be more susceptible to drug-associated effects on the QT interval [see Use in Specific Populations (8.5)] .
Hepatic dysfunction, including increased liver enzymes, and hepatocellular and/or cholestatic hepatitis, with or without jaundice, has been reported with clarithromycin. This hepatic dysfunction may be severe and is usually reversible. In some instances, hepatic failure with fatal outcome has been reported and generally has been associated with serious underlying diseases and/or concomitant medications. Symptoms of hepatitis can include anorexia, jaundice, dark urine, pruritus, or tender abdomen. Discontinue clarithromycin immediately if signs and symptoms of hepatitis occur.
In one clinical trial evaluating treatment with clarithromycin on outcomes in patients with coronary artery disease, an increase in risk of all-cause mortality one year or more after the end of treatment was observed in patients randomized to receive clarithromycin. 1 Clarithromycin for treatment of coronary artery disease is not an approved indication. The cause of the increased risk has not been established. Other epidemiologic studies evaluating this risk have shown variable results [see Adverse Ractions (6.1)] . Consider balancing this potential risk with the treatment benefits when prescribing clarithromycin in patients who have suspected or confirmed coronary artery disease.
Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including clarithromycin, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.
C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibacterial use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.
If CDAD is suspected or confirmed, ongoing antibacterial use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibacterial treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.
Clarithromycin should not be used in pregnant women except in clinical circumstances where no alternative therapy is appropriate. If clarithromycin is used during pregnancy, or if pregnancy occurs while the patient is taking this drug, the patient should be apprised of the potential hazard to the fetus. Clarithromycin has demonstrated adverse effects on pregnancy outcome and/or embryo-fetal development in monkeys, rats, mice, and rabbits at doses that produced plasma levels 2 times to 17 times the serum levels achieved in humans treated at the maximum recommended human doses [see Use in Specific Populations (8.1)] .
Exacerbation of symptoms of myasthenia gravis and new onset of symptoms of myasthenic syndrome has been reported in patients receiving clarithromycin therapy.
The following serious adverse reactions are described below and elsewhere in the labeling:
Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.
Based on pooled data across all indications, the most frequent adverse reactions for both adult and pediatric populations observed in clinical trials are abdominal pain, diarrhea, nausea, vomiting and dysgeusia. Also reported were dyspepsia, liver function test abnormal, anaphylactic reaction, candidiasis, headache, insomnia, and rash.
The subsequent subsections list the most common adverse reactions for prophylaxis and treatment of mycobacterial infections and duodenal ulcer associated with H. pylori infection. In general, these profiles are consistent with the pooled data described above.
Prophylaxis of Mycobacterial Infections
In AIDS patients treated with clarithromycin over long periods of time for prophylaxis against M. avium, it was often difficult to distinguish adverse reactions possibly associated with clarithromycin administration from underlying HIV disease or intercurrent illness. Median duration of treatment was 10.6 months for the clarithromycin group and 8.2 months for the placebo group.
|Body System b||Clarithromycin
|Body as a Whole|
|Skin & Appendages|
|Taste Perversion||8% c||0.3%|
a Includes those events possibly or probably related to study drug and excludes concurrent conditions
b 2% or greater Adverse Reaction Incidence Rates for either treatment group
c Significant higher incidence compared to the placebo-treated group
Discontinuation due to adverse reactions occurred in 18% of patients receiving clarithromycin compared to 17% of patients receiving placebo in this trial. Primary reasons for discontinuation in clarithromycin treated patients include headache, nausea, vomiting, depression, and taste perversion.
Changes in Laboratory Values
Selected laboratory adverse experiences that were reported during therapy in greater than 2 % of adult patients treated with clarithromycin in a randomized double-blind clinical trial involving 682 patients are presented in Table 4.
In immunocompromised patients receiving prophylaxis against M. avium, evaluations of laboratory values were made by analyzing those values outside the seriously abnormal value (i.e., the extreme high or low limit) for the specified test.
|Clarithromycin 500 mg
twice a day
|WBC Count||<1 x 10 9/L||2/103 (4%)||0/95|
|SGOT||>5 x ULN b||7/196 (4%)||5/208 (2%)|
|SGPT||>5 x ULN b||6/217 (3%)||4/232 (2%)|
a Includes only patients with baseline values within the normal range or borderline high (hematology variables) and within normal range or borderline low (chemistry variables)
b ULN= Upper Limit of Normal
Treatment of Mycobacterial Infections
The adverse reaction profiles for both the 500 mg and 1000 mg twice a day dose regimens were similar.
In AIDS patients and other immunocompromised patients treated with the higher doses of clarithromycin over long periods of time for mycobacterial infections, it was often difficult to distinguish adverse reactions possibly associated with clarithromycin administration from underlying signs of HIV disease or intercurrent illness.
The following analysis summarizes experience during the first 12 weeks of therapy with clarithromycin. Data are reported separately for trial 1 (randomized, double-blind) and trial 2 (open-labeled, compassionate use) and also combined. Adverse reactions were reported less frequently in trial 2, which may be due in part to differences in monitoring between the two studies.
In adult patients receiving clarithromycin 500 mg twice a day, the most frequently reported adverse reactions, considered possibly or possibly related to study drug, with an incidence of 5% or greater, are listed below (Table 5). Approximately 8% of the patients who received 500 mg twice a day and 12% of the patients who received 1000 mg twice a day discontinued therapy due to drug related adverse reactions during the first 12 weeks of therapy; adverse reactions leading to discontinuation in at least 2 patients included nausea, vomiting, abdominal pain, diarrhea, rash, and asthenia.
|Adverse Reaction||Trial 1
|a Includes those events possibly or probably related to study drug and excludes concurrent conditions|
A limited number of pediatric AIDS patients have been treated with clarithromycin suspension for mycobacterial infections. The most frequently reported adverse reactions excluding those due to the patient’s concurrent conditions were consistent with those observed in adult patients.
Changes in Laboratory Values
In the first 12 weeks of starting on clarithromycin 500 mg twice a day, 3% of patients has SGOT increases and 2% of patients has SGPT increases > 5 times the upper limit of normal in trial 2 (469 enrolled adult patients) while trial 1 (154 enrolled patients) had no elevation of transaminases. This includes only patients with baseline values within the normal range or borderline low.
Duodenal ulcer associated with H. pylori Infection
In clinical trials using combination therapy with clarithromycin plus omeprazole and amoxicillin, no adverse reactions specific to the combination of these drugs have been observed. Adverse reactions that have occurred have been limited to those that have been previously reported with clarithromycin, omeprazole or amoxicillin.
The adverse reaction profiles are shown below (Table 6) for four randomized double-blind clinical trials in which patients received the combination of clarithromycin 500 mg three times a day, and omeprazole 40 mg daily for 14 days, followed by omeprazole 20 mg once a day, (three studies) or 40 mg once a day (one study) for an additional 14 days. Of the 346 patients who received the combination, 3.5% of patients discontinued drug due to adverse reactions.
|Adverse Reaction||Clarithromycin + Omeprazole
% of Patients
% of Patients
% of Patients a
|a Only two of four studies|
Changes in Laboratory Values
Changes in laboratory values with possible clinical significance in patients taking clarithromycin and omeprazole in four randomized double-blind trials in 945 patients are as follows:
Hepatic: elevated direct bilirubin <1%; GGT <1%; SGOT (AST) <1%; SGPT (ALT) <1%, Renal: elevated serum creatinine <1%.
Less Frequent Adverse Reactions Observed During Clinical Trials of Clarithromycin
Based on pooled data across all indications, the following adverse reactions were observed in clinical trials with clarithromycin at a rate less than 1%:
Blood and Lymphatic System Disorders: Leukopenia, neutropenia, thrombocythemia, eosinophilia
Cardiac Disorders: Electrocardiogram QT prolonged, cardiac arrest, atrial fibrillation, extrasystoles, palpitations
Ear and Labyrinth Disorders: Vertigo, tinnitus, hearing impaired
Gastrointestinal Disorders: Stomatitis, glossitis, esophagitis, gastrooesophageal reflux disease, gastritis, proctalgia, abdominal distension, constipation, dry mouth, eructation, flatulence
General Disorders and Administration Site Conditions: Malaise, pyrexia, asthenia, chest pain, chills, fatigue
Hepatobiliary Disorders: Cholestasis, hepatitis
Immune System Disorders: Hypersensitivity
Infections and Infestations: Cellulitis, gastroenteritis, infection, vaginal infection
Investigations: Blood bilirubin increased, blood alkaline phosphatase increased, blood lactate dehydrogenase increased, albumin globulin ratio abnormal
Metabolism and Nutrition Disorders: Anorexia, decreased appetite
Musculoskeletal and Connective Tissue Disorders: Myalgia, muscle spasms, nuchal rigidity
Nervous System Disorders: Dizziness, tremor, loss of consciousness, dyskinesia, somnolence
Psychiatric Disorders: Anxiety, nervousness
Renal and Urinary Disorders: Blood creatinine increased, blood urea increased
Respiratory, Thoracic and Mediastinal Disorders: Asthma, epistaxis, pulmonary embolism
Skin and Subcutaneous Tissue Disorders: Urticaria, dermatitis bullous, pruritus, hyperhidrosis, rash maculo-papular
Gastrointestinal Adverse Reactions
In the acute exacerbation of chronic bronchitis and acute maxillary sinusitis studies overall gastrointestinal adverse reactions were reported by a similar proportion of patients taking either clarithromycin tablets or clarithromycin extended-release tablets; however, patients taking clarithromycin extended-release tablets reported significantly less severe gastrointestinal symptoms compared to patients taking clarithromycin tablets. In addition, patients taking clarithromycin extended-release tablets had significantly fewer premature discontinuations for drug-related gastrointestinal or abnormal taste adverse reactions compared to clarithromycin tablets.
All-Cause Mortality in Patients with Coronary Artery Disease 1 to 10 Years Following Clarithromycin Exposure
In one clinical trial evaluating treatment with clarithromycin on outcomes in patients with coronary artery disease, an increase in risk of all-cause mortality was observed in patients randomized to clarithromycin. Clarithromycin for treatment of coronary artery disease is not an approved indication. Patients were treated with clarithromycin or placebo for 14 days and observed for primary outcome events (e.g., all-cause mortality or non-fatal cardiac events) for several years.1 A numerically higher number of primary outcome events in patients randomized to receive clarithromycin was observed with a hazard ratio of 1.06 (95% confidence interval 0.98 to 1.14). However, at follow-up 10 years post-treatment, there were 866 (40%) deaths in the clarithromycin group and 815 (37%) deaths in the placebo group that represented a hazard ratio for all-cause mortality of 1.10 (95% confidence interval 1.00 to 1.21). The difference in the number of deaths emerged after one year or more after the end of treatment.
The cause of the difference in all-cause mortality has not been established. Other epidemiologic studies evaluating this risk have shown variable results [see Warnings and Precautions (5.5)] .
The following adverse reactions have been identified during post-approval use of clarithromycin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Blood and Lymphatic System: Thrombocytopenia, agranulocytosis
Cardiac: Ventricular arrhythmia, ventricular tachycardia, torsades de pointes
Ear and Labyrinth: Deafness was reported chiefly in elderly women and was usually reversible.
Gastrointestinal: Pancreatitis acute, tongue discoloration, tooth discoloration was reported and was usually reversible with professional cleaning upon discontinuation of the drug.
There have been reports of clarithromycin extended-release tablets in the stool, many of which have occurred in patients with anatomic (including ileostomy or colostomy) or functional gastrointestinal disorders with shortened GI transit times. In several reports, tablet residues have occurred in the context of diarrhea. It is recommended that patients who experience tablet residue in the stool and no improvement in their condition should be switched to a different clarithromycin formulation (e.g. suspension) or another antibacterial drug.
Hepatobiliary: Hepatic failure, jaundice hepatocellular. Adverse reactions related to hepatic dysfunction have been reported with clarithromycin [see Warnings and Precautions (5.2)] .
Infections and Infestations: Pseudomembranous colitis [see Warnings and Precautions (5.6)]
Immune System: Anaphylactic reactions, angioedema
Investigations: Prothrombin time prolonged, white blood cell count decreased, international normalized ratio increased. Abnormal urine color has been reported, associated with hepatic failure.
Metabolism and Nutrition: Hypoglycemia has been reported in patients taking oral hypoglycemic agents or insulin.
Musculoskeletal and Connective Tissue: Myopathy rhabdomyolysis was reported and in some of the reports, clarithromycin was administered concomitantly with statins, fibrates, colchicine or allopurinol [see Contraindications (4.5) and Warnings and Precautions (5.4)] .
Nervous System: Parosmia, anosmia, ageusia, paresthesia and convulsions
Psychiatric: Abnormal behavior, confusional state, depersonalization, disorientation, hallucination, depression, manic behavior, abnormal dream, psychotic disorder. These disorders usually resolve upon discontinuation of the drug.
Renal and Urinary: Nephritis interstitial, renal failure
Skin and Subcutaneous Tissue: Stevens-Johnson syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms (DRESS), Henoch-Schonlein purpura, acne, acute generalized exanthematous pustulosis
Co-administration of clarithromycin is known to inhibit CYP3A, and a drug primarily metabolized by CYP3A may be associated with elevations in drug concentrations that could increase or prolong both therapeutic and adverse effects of the concomitant drug.
Clarithromycin should be used with caution in patients receiving treatment with other drugs known to be CYP3A enzyme substrates, especially if the CYP3A substrate has a narrow safety margin (e.g., carbamazepine) and/or the substrate is extensively metabolized by this enzyme. Adjust dosage when appropriate and monitor serum concentrations of drugs primarily metabolized by CYP3A closely in patients concurrently receiving clarithromycin.
|Drugs That Are Affected By Clarithromycin|
|Drug(s) with Pharmacokinetics Affected by Clarithromycin||Recommendation||Comments|
|Not Recommended||Disopyramide, Quinidine: There have been postmarketing reports of
torsades de pointes occurring with concurrent use of clarithromycin and quinidine or disopyramide. Electrocardiograms should be monitored for QTc prolongation during coadministration of clarithromycin with these drugs
[see Warnings and Precautions
Serum concentrations of these medications should also be monitored. There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with disopyramide and quinidine.
There have been postmarketing reports of hypoglycemia with the concomitant administration of clarithromycin and disopyramide. Therefore, blood glucose levels should be monitored during concomitant administration of clarithromycin and disopyramide.
|Digoxin||Use With Caution||Digoxin: Digoxin is a substrate for P-glycoprotein (Pgp) and clarithromycin is known to inhibit Pgp. When clarithromycin and digoxin are co-administered, inhibition of Pgp by clarithromycin may lead to increased exposure of digoxin. Elevated digoxin serum concentrations in patients receiving clarithromycin and digoxin concomitantly have been reported in postmarketing surveillance. Some patients have shown clinical signs consistent with digoxin toxicity, including potentially fatal arrhythmias. Monitoring of serum digoxin concentrations should be considered, especially for patients with digoxin concentrations in the upper therapeutic range.
|Warfarin||Use With Caution||Oral anticoagulants: Spontaneous reports in the postmarketing period suggest that concomitant administration of clarithromycin and oral anticoagulants may potentiate the effects of the oral anticoagulants. Prothrombin times should be carefully monitored while patients are receiving clarithromycin and oral anticoagulants simultaneously
[see Warnings and Precautions
|Carbamazepine||Use With Caution||Carbamazepine: Concomitant administration of single doses of clarithromycin and carbamazepine has been shown to result in increased plasma concentrations of carbamazepine. Blood level monitoring of carbamazepine may be considered. Increased serum concentrations of carbamazepine were observed in clinical trials with clarithromycin. There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with carbamazepine.
|Itraconazole||Use With Caution||Itraconazole: Both clarithromycin and itraconazole are substrates and inhibitors of CYP3A, potentially leading to a bi-directional drug interaction when administered concomitantly (see also
Itraconazole under “Drugs That Affect Clarithromycin” in the table below). Clarithromycin may increase the plasma concentrations of itraconazole. Patients taking itraconazole and clarithromycin concomitantly should be monitored closely for signs or symptoms of increased or prolonged adverse reactions.
|Fluconazole||No Dose Adjustment
||Fluconazole: [see Pharmacokinetics (12.3)]|
|Colchicine (in patients with renal or hepatic impairment)
||Contraindicated||Colchicine: Colchicine is a substrate for both CYP3A and the efflux transporter, P-glycoprotein (Pgp). Clarithromycin and other macrolides are known to inhibit CYP3A and Pgp. The dose of colchicine should be reduced when co-administered with clarithromycin in patients with normal renal and hepatic function
(4.4)and Warnings and Precautions
|Colchicine (in patients with normal renal and hepatic function)||Use With Caution|
|Quetiapine||Quetiapine: Quetiapine is a substrate for CYP3A4, which is inhibited by clarithromycin. Co-administration with clarithromycin could result in increased quetiapine exposure and possible quetiapine related toxicities. There have been postmarketing reports of somnolence, orthostatic hypotension, altered state of consciousness, neuroleptic malignant syndrome, and QT prolongation during concomitant administration. Refer to quetiapine prescribing information for recommendations on dose reduction if co-administered with CYP3A4 inhibitors such as clarithromycin.
|Tolterodine (patients deficient in CYP2D6 activity)||Use With Caution||Tolterodine: The primary route of metabolism for tolterodine is via CYP2D6. However, in a subset of the population devoid of CYP2D6, the identified pathway of metabolism is via CYP3A. In this population subset, inhibition of CYP3A results in significantly higher serum concentrations of tolterodine. Tolterodine 1 mg twice daily is recommended in patients deficient in CYP2D6 activity (poor metabolizers) when co-administered with clarithromycin.
|Atazanavir||Use With Caution||Atazanavir: Both clarithromycin and atazanavir are substrates and inhibitors of CYP3A, and there is evidence of a bi-directional drug interaction (see
Atazanavir under “Drugs That Affect Clarithromycin” in the table below)
|Saquinavir (in patients with decreased renal function)||Saquinavir: Both clarithromycin and saquinavir are substrates and inhibitors of CYP3A and there is evidence of a bi-directional drug interaction (see
Saquinavir under “Drugs That Affect Clarithromycin” in the table below)
|Ritonavir, Etravirine: (see
Ritonavir and Etravirine under “Drugs That Affect Clarithromycin” in the table below)
|Maraviroc||Maraviroc: Clarithromycin may result in increases in maraviroc exposures by inhibition of CYP3A metabolism. See Selzentry
® prescribing information for dose recommendation when given with strong CYP3A inhibitors such as clarithromycin.
|Boceprevir (in patients with normal renal function)
|No Dose Adjustment||Boceprevir: Both clarithromycin and boceprevir are substrates and inhibitors of CYP3A, potentially leading to a bi-directional drug interaction when co-administered. No dose adjustments are necessary for patients with normal renal function (see Victrelis
® prescribing information).
|Zidovudine||Zidovudine: Simultaneous oral administration of clarithromycin immediate-release tablets and zidovudine to HIV-infected adult patients may result in decreased steady-state zidovudine concentrations. Administration of clarithromycin and zidovudine should be separated by at least two hours
The impact of co-administration of clarithromycin extended-release tablets or granules and zidovudine has not been evaluated.
|Calcium Channel Blockers:
|Verapamil||Use With Caution||Verapamil: Hypotension, bradyarrhythmias, and lactic acidosis have been observed in patients receiving concurrent verapamil,
[see Warnings and Precautions
|Amlodipine, Diltiazem:[See Warnings and Precautions (5.4)]|
|Nifedipine||Nifedipine: Nifedipine is a substrate for CYP3A. Clarithromycin and other macrolides are known to inhibit CYP3A. There is potential of CYP3A-mediated interaction between nifedipine and clarithromycin. Hypotension and peripheral edema were observed when clarithromycin was taken concomitantly with nifedipine
[see Warnings and Precautions
|Contraindicated||Ergotamine, Dihydroergotamine: Postmarketing reports indicate that coadministration of clarithromycin with ergotamine or dihydroergotamine has been associated with acute ergot toxicity characterized by vasospasm and ischemia of the extremities and other tissues including the central nervous system
|HMG-CoA Reductase Inhibitors:
|Contraindicated||Lovastatin, Simvastatin, Atorvastatin, Pravastatin, Fluvastatin:[See Contraindications
(4.5)and Warnings and Precautions
|Use With Caution|
||No Dose Adjustment
|Use With Caution||Nateglinide, Pioglitazone, Repaglinide, Rosiglitazone:[See Warnings and Precautions
(5.4)and Adverse Reactions
|Insulin||Insulin:[See Warnings and Precautions
(5.4) and Adverse Reactions
|Cyclosporine||Use With Caution||Cyclosporine: There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with cyclosporine.
|Tacrolimus||Tacrolimus: There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with tacrolimus.
|Use With Caution||Sildenafil, Tadalafil, Vardenafil: Each of these phosphodiesterase inhibitors is primarily metabolized by CYP3A, and CYP3A will be inhibited by concomitant administration of clarithromycin. Co-administration of clarithromycin with sildenafil, tadalafil, or vardenafil will result in increased exposure of these phosphodiesterase inhibitors. Co-administration of these phosphodiesterase inhibitors with clarithromycin is not recommended. Increased systemic exposure of these drugs may occur with clarithromycin; reduction of dosage for phosphodiesterase inhibitors should be considered (see their respective prescribing information).
|Proton Pump Inhibitors:
|Omeprazole||No Dose Adjustment||Omeprazole: The mean 24-hour gastric pH value was 5.2 when omeprazole was administered alone and 5.7 when coadministered with clarithromycin as a result of increased omeprazole exposures
Omeprazole under “Drugs That Affect Clarithromycin” in the table below).
|Theophylline||Use With Caution||Theophylline: Clarithromycin use in patients who are receiving theophylline may be associated with an increase of serum theophylline concentrations
. Monitoring of serum theophylline concentrations should be considered for patients receiving high doses of theophylline or with baseline concentrations in the upper therapeutic range.
|Triazolobenzodiazepines and Other Related Benzodiazepines:
|Midazolam||Use With Caution||Midazolam: When oral midazolam is co-administered with clarithromycin, dose adjustments may be necessary and possible prolongation and intensity of effect should be anticipated
[see Warnings and Precautions
|Triazolam, Alprazolam: Caution and appropriate dose adjustments should be considered when triazolam or alprazolam is co-administered with clarithromycin. There have been postmarketing reports of drug interactions and central nervous system (CNS) effects (e.g., somnolence and confusion) with the concomitant use of clarithromycin and triazolam. Monitoring the patient for increased CNS pharmacological effects is suggested.
In postmarketing experience, erythromycin has been reported to decrease the clearance of triazolam and midazolam, and thus, may increase the pharmacologic effect of these benzodiazepines.
|No Dose Adjustment||Temazepam, Nitrazepam, Lorazepam: For benzodiazepines which are not metabolized by CYP3A (e.g., temazepam, nitrazepam, lorazepam), a clinically important interaction with clarithromycin is unlikely.
|Cytochrome P450 Inducers:
|Rifabutin||Use With Caution||Rifabutin: Concomitant administration of rifabutin and clarithromycin resulted in an increase in rifabutin, and decrease in clarithromycin serum levels together with an increased risk of uveitis (see
Rifabutin under “Drugs That Affect Clarithromycin” in the table below).
|Other Drugs Metabolized by CYP3A:
St. John’s Wort
|Use With Caution||There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with alfentanil, methylprednisolone, cilostazol, bromocriptine, vinblastine, phenobarbital, and St. John’s Wort.|
|Other Drugs Metabolized by CYP450 Isoforms Other than CYP3A:
|Use With Caution||There have been postmarketing reports of interactions of clarithromycin with drugs not thought to be metabolized by CYP3A, including hexobarbital, phenytoin, and valproate.
|Drugs that Affect Clarithromycin|
|Drug(s) that Affect the Pharmacokinetics of Clarithromycin||Recommendation||Comments|
||Use With Caution||Itraconazole: Itraconazole may increase the plasma concentrations of clarithromycin. Patients taking itraconazole and clarithromycin concomitantly should be monitored closely for signs or symptoms of increased or prolonged adverse reactions (see also
Itraconazole under “Drugs That Are Affected By Clarithromycin” in the table above).
|Atazanavir||Use With Caution||Atazanavir: When clarithromycin is co-administered with atazanavir, the dose of clarithromycin should be decreased by 50%
[see Clinical Pharmacology
Since concentrations of 14-OH clarithromycin are significantly reduced when clarithromycin is co-administered with atazanavir, alternative antibacterial therapy should be considered for indications other than infections due to Mycobacterium avium complex. Doses of clarithromycin greater than 1000 mg per day should not be co-administered with protease inhibitors.
|Ritonavir (in patients with decreased renal function)||Ritonavir: Since concentrations of 14-OH clarithromycin are significantly reduced when clarithromycin is co-administered with ritonavir, alternative antibacterial therapy should be considered for indications other than infections due to
Mycobacterium avium[see Pharmacokinetics
Doses of clarithromycin greater than 1000 mg per day should not be co-administered with protease inhibitors.
|Saquinavir (in patients with decreased renal function)||Saquinavir: When saquinavir is co-administered with ritonavir, consideration should be given to the potential effects of ritonavir on clarithromycin (refer to ritonavir above)
|Etravirine||Etravirine: Clarithromycin exposure was decreased by etravirine; however, concentrations of the active metabolite, 14-OH-clarithromycin, were increased. Because 14-OH-clarithromycin has reduced activity against
Mycobacterium avium complex (MAC), overall activity against this pathogen may be altered; therefore alternatives to clarithromycin should be considered for the treatment of MAC.
|Saquinavir (in patients with normal renal function)||No Dose Adjustment|
|Ritonavir (in patients with normal renal function)
|Proton Pump Inhibitors:
|Omeprazole||Use With Caution||Omeprazole: Clarithromycin concentrations in the gastric tissue and mucus were also increased by concomitant administration of omeprazole
|Miscellaneous Cytochrome P450 Inducers:
|Use With Caution||Inducers of CYP3A enzymes, such as efavirenz, nevirapine, rifampicin, rifabutin, and rifapentine will increase the metabolism of clarithromycin, thus decreasing plasma concentrations of clarithromycin, while increasing those of 14-OH-clarithromycin. Since the microbiological activities of clarithromycin and 14-OH-clarithromycin are different for different bacteria, the intended therapeutic effect could be impaired during concomitant administration of clarithromycin and enzyme inducers. Alternative antibacterial treatment should be considered when treating patients receiving inducers of CYP3A. There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with rifabutin (see
Rifabutin under “Drugs That Are Affected By Clarithromycin” in the table above).
Pregnancy Category C
Clarithromycin should not be used in pregnant women except in clinical circumstances where no alternative therapy is appropriate. If pregnancy occurs while taking this drug, the patient should be apprised of the potential hazard to the fetus [see Warnings and Precautions (5.7)] .
Four teratogenicity studies in rats (three with oral doses and one with intravenous doses up to 160 mg/kg/day administered during the period of major organogenesis) and two in rabbits at oral doses up to 125 mg/kg/day (approximately twice the recommended maximum human dose based on mg/m 2) or intravenous doses of 30 mg/kg/day administered during gestation days 6 to 18 failed to demonstrate any teratogenicity from clarithromycin. Two additional oral studies in a different rat strain at similar doses and similar conditions demonstrated a low incidence of cardiovascular anomalies at doses of 150 mg/kg/day administered during gestation days 6 to 15. Plasma levels after 150 mg/kg/day were twice the human serum levels. Four studies in mice revealed a variable incidence of cleft palate following oral doses of 1000 mg/kg/day (2 and 4 times the recommended maximum human dose based on mg/m 2, respectively) during gestation days 6 to 15. Cleft palate was also seen at 500 mg/kg/day. The 1000 mg/kg/day exposure resulted in plasma levels 17 times the human serum levels. In monkeys, an oral dose of 70 mg/kg/day produced fetal growth retardation at plasma levels that were twice the human serum levels.
Caution should be exercised when clarithromycin is administered to nursing women. The development and health benefits of human milk feeding should be considered along with the mother’s clinical need for clarithromycin and any potential adverse effects on the human milk fed child from the drug or from the underlying maternal condition.
Clarithromycin and its active metabolite 14-hydroxy clarithromycin are excreted in human milk. Serum and milk samples were obtained after 3 days of treatment, at steady state, from one published study of 12 lactating women who were taking clarithromycin 250 mg orally twice daily. Based on the limited data from this study, and assuming milk consumption of 150 mL/kg/day, an exclusively human milk fed infant would receive an estimated average of 136 mcg/kg/day of clarithromycin and its active metabolite, with this maternal dosage regimen. This is less than 2% of the maternal weight-adjusted dose (7.8 mg/kg/day, based on the average maternal weight of 64 kg), and less than 1% of the pediatric dose (15 mg/kg/day) for children greater than 6 months of age.
A prospective observational study of 55 breastfed infants of mothers taking a macrolide antibacterial (6 were exposed to clarithromycin) were compared to 36 breastfed infants of mothers taking amoxicillin. Adverse reactions were comparable in both groups. Adverse reactions occurred in 12.7% of infants exposed to macrolides and included rash, diarrhea, loss of appetite, and somnolence.
The safety and effectiveness of clarithromycin extended-release tablets in the treatment of pediatric patients has not been established.
Safety and effectiveness of clarithromycin in pediatric patients under 6 months of age have not been established. The safety of clarithromycin has not been studied in MAC patients under the age of 20 months.
In a steady-state study in which healthy elderly subjects (65 years to 81 years of age) were given 500 mg of clarithromycin every 12 hours, the maximum serum concentrations and area under the curves of clarithromycin and 14-OH clarithromycin were increased compared to those achieved in healthy young adults. These changes in pharmacokinetics parallel known age-related decreases in renal function. In clinical trials, elderly patients did not have an increased incidence of adverse reactions when compared to younger patients. Consider dosage adjustment in elderly patients with severe renal impairment. Elderly patients may be more susceptible to development of torsades de pointes arrhythmias than younger patients [see Warnings and Precautions (5.3)] .
Most reports of acute kidney injury with calcium channel blockers metabolized by CYP3A4 (e.g., verapamil, amlodipine, diltiazem, nifedipine) involved elderly patients 65 years of age or older [see Warnings and Precautions (5.4)] .
Especially in elderly patients, there have been reports of colchicine toxicity with concomitant use of clarithromycin and colchicine, some of which occurred in patients with renal insufficiency. Deaths have been reported in some patients [see Contraindications (4.4)and Warnings and Precautions (5.4)] .
Clarithromycin is principally excreted via the liver and kidney. Clarithromycin may be administered without dosage adjustment to patients with hepatic impairment and normal renal function. However, in the presence of severe renal impairment with or without coexisting hepatic impairment, decreased dosage or prolonged dosing intervals may be appropriate [see Dosage and Administration (2.5)] .
Overdosage of clarithromycin can cause gastrointestinal symptoms such as abdominal pain, vomiting, nausea, and diarrhea.
Treat adverse reactions accompanying overdosage by the prompt elimination of unabsorbed drug and supportive measures. As with other macrolides, clarithromycin serum concentrations are not expected to be appreciably affected by hemodialysis or peritoneal dialysis.
Clarithromycin is a semi-synthetic macrolide antimicrobial for oral use. Chemically, it is 6- 0-methylerythromycin. The molecular formula is C 38H 69NO 13, and the molecular weight is 747.96. The structural formula is:
Figure 1: Structure of Clarithromycin
Clarithromycin is a white to off-white crystalline powder. It is soluble in acetone, slightly soluble in methanol, ethanol, and acetonitrile, and practically insoluble in water.
Clarithromycin is available as extended-release tablets.
Each white or off-white, capsular-shaped film-coated Clarithromycin Extended-release Tablets, USP contains 500 mg of clarithromycin and the following inactive ingredients: glyceryl dibehenate, hypromellose, lactose monohydrate, magnesium stearate, polyethylene glycol, and titanium dioxide.
Clarithromycin Extended-release Tablets, USP meets the dissolution specifications which were established according to the USP monograph-Clarithromycin Extended-release Tablets Test 2.
Clarithromycin is a macrolide antimicrobial drug [see Microbiology (12.4)] .
Clarithromycin Immediate-Release Tablets
The absolute bioavailability of 250 mg clarithromycin tablets was approximately 50%. For a single 500 mg dose of clarithromycin, food slightly delays the onset of clarithromycin absorption, increasing the peak time from approximately 2 to 2.5 hours. Food also increases the clarithromycin peak plasma concentration by about 24%, but does not affect the extent of clarithromycin bioavailability. Food does not affect the onset of formation of the active metabolite, 14-OH clarithromycin or its peak plasma concentration but does slightly decrease the extent of metabolite formation, indicated by an 11% decrease in area under the plasma concentration-time curve (AUC). Therefore, clarithromycin tablets may be given without regard to food. In non-fasting healthy human subjects (males and females), peak plasma concentrations were attained within 2 to 3 hours after oral dosing.
Clarithromycin Extended-Release Tablets
Clarithromycin extended-release tablets provide extended absorption of clarithromycin from the gastrointestinal tract after oral administration. Relative to an equal total daily dose of immediate-release clarithromycin tablets, clarithromycin extended-release tablets provide lower and later steady-state peak plasma concentrations but equivalent 24-hour AUCs for both clarithromycin and its microbiologically-active metabolite, 14-OH clarithromycin. While the extent of formation of 14-OH clarithromycin following administration of clarithromycin extended-release tablets (2 x 500 mg tablets once daily) is not affected by food, administration under fasting conditions is associated with approximately 30% lower clarithromycin AUC relative to administration with food. Therefore, clarithromycin extended-release tablets should be taken with food.
Figure 2: Steady-State Clarithromycin Plasma Concentration-Time Profiles
Clarithromycin Granules For Oral Suspension
When 250 mg doses of clarithromycin as an oral suspension were administered to fasting healthy adult subjects, peak plasma concentrations were attained around 3 hours after dosing.
For adult patients, the bioavailability of 10 mL of the 125 mg/5 mL suspension or 10 mL of the 250 mg/5 mL suspension is similar to a 250 mg or 500 mg tablet, respectively.
In adults given 250 mg clarithromycin as suspension (n = 22), food appeared to decrease mean peak plasma clarithromycin concentrations from 1.2 (± 0.4) mcg/mL to 1.0 (± 0.4) mcg/mL and the extent of absorption from 7.2 (± 2.5) hr•mcg/mL to 6.5 (± 3.7) hr•mcg/mL.
Clarithromycin and the 14-OH clarithromycin metabolite distribute readily into body tissues and fluids. There are no data available on cerebrospinal fluid penetration. Because of high intracellular concentrations, tissue concentrations are higher than serum concentrations. Examples of tissue and serum concentrations are presented below.
|CONCENTRATION (after 250 mg every 12 hours)|
Metabolism and Elimination
Clarithromycin Immediate-Release Tablets
Steady-state peak plasma clarithromycin concentrations were attained within 3 days and were approximately 1 mcg/mL to 2 mcg/mL with a 250 mg dose administered every 12 hours and 3 mcg/mL to 4 mcg/mL with a 500 mg dose administered every 8 hours to 12 hours. The elimination half-life of clarithromycin was about 3 hours to 4 hours with 250 mg administered every 12 hours but increased to 5 hours to 7 hours with 500 mg administered every 8 hours to 12 hours. The nonlinearity of clarithromycin pharmacokinetics is slight at the recommended doses of 250 mg and 500 mg administered every 8 hours to 12 hours. With a 250 mg every 12 hours dosing, the principal metabolite, 14-OH clarithromycin, attains a peak steady-state concentration of about 0.6 mcg/mL and has an elimination half-life of 5 hours to 6 hours. With a 500 mg every 8 hours to 12 hours dosing, the peak steady-state concentration of 14-OH clarithromycin is slightly higher (up to 1 mcg/mL), and its elimination half-life is about 7 hours to 9 hours. With any of these dosing regimens, the steady-state concentration of this metabolite is generally attained within 3 days to 4 days.
After a 250 mg tablet every 12 hours, approximately 20% of the dose is excreted in the urine as clarithromycin, while after a 500 mg tablet every 12 hours, the urinary excretion of clarithromycin is somewhat greater, approximately 30%. In comparison, after an oral dose of 250 mg (125 mg/5 mL) suspension every 12 hours, approximately 40% is excreted in urine as clarithromycin. The renal clearance of clarithromycin is, however, relatively independent of the dose size and approximates the normal glomerular filtration rate. The major metabolite found in urine is 14-OH clarithromycin, which accounts for an additional 10% to 15% of the dose with either a 250 mg or a 500 mg tablet administered every 12 hours.
Clarithromycin Extended-Release Tablets
In healthy human subjects, steady-state peak plasma clarithromycin concentrations of approximately 2 mcg/mL to 3 mcg/mL were achieved about 5 hours to 8 hours after oral administration of 1000 mg clarithromycin extended-release tablets once daily; for 14-OH clarithromycin, steady-state peak plasma concentrations of approximately 0.8 mcg/mL were attained about 6 hours to 9 hours after dosing. Steady-state peak plasma clarithromycin concentrations of approximately 1 mcg/mL to 2 mcg/mL were achieved about 5 hours to 6 hours after oral administration of a single 500 mg clarithromycin extended-release tablets once daily; for 14-OH clarithromycin, steady-state peak plasma concentrations of approximately 0.6 mcg/mL were attained about 6 hours after dosing.
Steady-state peak plasma concentrations were attained in 2 days to 3 days and were approximately 2 mcg/mL for clarithromycin and 0.7 mcg/mL for 14-OH clarithromycin when 250-mg doses of the clarithromycin suspension were administered every 12 hours. Elimination half-life of clarithromycin (3 hours to 4 hours) and that of 14-OH clarithromycin (5 hours to 7 hours) were similar to those observed at steady state following administration of equivalent doses of clarithromycin immediate-release tablets.
Specific Populations for Clarithromycin Immediate-release Tablets, Clarithromycin Extended-release Tablets, and Clarithromycin Granules Formulations
Clarithromycin Granules For Oral Suspension in Pediatric Patients
Clarithromycin penetrates into the middle ear fluid of pediatric patients with secretory otitis media.
|CONCENTRATION (after 7.5 mg/kg every 12 hours for 5 doses)|
|Analyte||Middle Ear Fluid
When pediatric patients (n = 10) were administered a single oral dose of 7.5 mg/kg clarithromycin as an oral suspension, food increased mean peak plasma clarithromycin concentrations from 3.6 (± 1.5) mcg/mL to 4.6 (± 2.8) mcg/mL and the extent of absorption from 10.0 (± 5.5) hr•mcg/mL to 14.2 (± 9.4) hr•mcg/mL.
In pediatric patients requiring antibacterial therapy, administration of 7.5 mg/kg every 12 hours of clarithromycin as an oral suspension generally resulted in steady-state peak plasma concentrations of 3 mcg/mL to 7 mcg/mL for clarithromycin and 1 mcg/mL to 2 mcg/mL for 14-OH clarithromycin.
In HIV-infected pediatric patients taking 15 mg/kg of clarithromycin as an oral suspension every 12 hours, steady-state clarithromycin peak concentrations generally ranged from 6 mcg/mL to 15 mcg/mL.
Steady-state concentrations of clarithromycin and 14-OH clarithromycin observed following administration of 500 mg doses of clarithromycin every 12 hours to adult patients with HIV infection were similar to those observed in healthy volunteers. In adult HIV-infected patients taking 500-mg or 1000-mg doses of clarithromycin every 12 hours, steady-state clarithromycin C max values ranged from 2 mcg/mL to 4 mcg/mL and 5 mcg/mL to 10 mcg/mL, respectively.
The steady-state concentrations of clarithromycin in subjects with impaired hepatic function did not differ from those in normal subjects; however, the 14-OH clarithromycin concentrations were lower in the hepatically impaired subjects. The decreased formation of 14-OH clarithromycin was at least partially offset by an increase in renal clearance of clarithromycin in the subjects with impaired hepatic function when compared to healthy subjects.
Following administration of fluconazole 200 mg daily and clarithromycin 500 mg twice daily to 21 healthy volunteers, the steady-state clarithromycin C min and AUC increased 33% and 18%, respectively. Clarithromycin exposures were increased and steady-state concentrations of 14-OH clarithromycin were not significantly affected by concomitant administration of fluconazole.
When a single dose of colchicine 0.6 mg was administered with clarithromycin 250 mg BID for 7 days, the colchicine C max increased 197% and the AUC 0-∞ increased 239% compared to administration of colchicine alone.
Following administration of clarithromycin (500 mg twice daily) with atazanavir (400 mg once daily), the clarithromycin AUC increased 94%, the 14-OH clarithromycin AUC decreased 70% and the atazanavir AUC increased 28%.
Concomitant administration of clarithromycin and ritonavir (n = 22) resulted in a 77% increase in clarithromycin AUC and a 100% decrease in the AUC of 14-OH clarithromycin.
Following administration of clarithromycin (500 mg bid) and saquinavir (soft gelatin capsules, 1200 mg tid) to 12 healthy volunteers, the steady-state saquinavir AUC and C max increased 177% and 187% respectively compared to administration of saquinavir alone. Clarithromycin AUC and C max increased 45% and 39% respectively, whereas the 14–OH clarithromycin AUC and C max decreased 24% and 34% respectively, compared to administration with clarithromycin alone.
Simultaneous administration of clarithromycin tablets and didanosine to 12 HIV-infected adult patients resulted in no statistically significant change in didanosine pharmacokinetics.
Following administration of clarithromycin 500 mg tablets twice daily with zidovudine 100 mg every 4 hours, the steady-state zidovudine AUC decreased 12% compared to administration of zidovudine alone (n=4). Individual values ranged from a decrease of 34% to an increase of 14%. When clarithromycin tablets were administered two to four hours prior to zidovudine, the steady-state zidovudine C max increased 100% whereas the AUC was unaffected (n=24).
Clarithromycin 500 mg every 8 hours was given in combination with omeprazole 40 mg daily to healthy adult subjects. The steady-state plasma concentrations of omeprazole were increased (C max, AUC 0-24, and t½ increases of 30%, 89%, and 34%, respectively), by the concomitant administration of clarithromycin.
The plasma levels of clarithromycin and 14–OH clarithromycin were increased by the concomitant administration of omeprazole. For clarithromycin, the mean C max was 10% greater, the mean C min was 27% greater, and the mean AUC 0-8 was 15% greater when clarithromycin was administered with omeprazole than when clarithromycin was administered alone. Similar results were seen for 14–OH clarithromycin, the mean C max was 45% greater, the mean C min was 57% greater, and the mean AUC 0-8 was 45% greater. Clarithromycin concentrations in the gastric tissue and mucus were also increased by concomitant administration of omeprazole.
|Clarithromycin Tissue Concentrations 2 hours after Dose (mcg/mL)/(mcg/g)|
|Clarithromycin||5||10.48 ± 2.01||20.81 ± 7.64||4||4.15 ± 7.74|
|Clarithromycin + Omeprazole||5||19.96 ± 4.71||24.25 ± 6.37||4||39.29 ± 32.79|
In two studies in which theophylline was administered with clarithromycin (a theophylline sustained-release formulation was dosed at either 6.5 mg/kg or 12 mg/kg together with 250 or 500 mg q12h clarithromycin), the steady-state levels of C max, C min, and the area under the serum concentration time curve (AUC) of theophylline increased about 20%.
When a single dose of midazolam was co-administered with clarithromycin tablets (500 mg twice daily for 7 days), midazolam AUC increased 174% after intravenous administration of midazolam and 600% after oral administration.
For information about other drugs indicated in combination with clarithromycin, refer to their full prescribing information, CLINICAL PHARMACOLOGY section.
Mechanism of Action
Clarithromycin exerts its antibacterial action by binding to the 50S ribosomal subunit of susceptible bacteria resulting in inhibition of protein synthesis.
The major routes of resistance are modification of the 23S rRNA in the 50S ribosomal subunit to insensitivity or drug efflux pumps. Beta-lactamase production should have no effect on clarithromycin activity.
Most isolates of methicillin-resistant and oxacillin-resistant staphylococci are resistant to clarithromycin.
Clarithromycin has been shown to be active against most of the isolates of the following microorganisms both in vitro and in clinical infections [see Indications and Usage (1)] .
At least 90 percent of the microorganisms listed below exhibit in vitro minimum inhibitory concentrations (MICs) less than or equal to the clarithromycin susceptible MIC breakpoint for organisms of similar type to those shown in Table 11. However, the efficacy of clarithromycin in treating clinical infections due to these microorganisms has not been established in adequate and well-controlled clinical trials.
Susceptibility Testing Methods (Excluding Mycobacteria and Helicobacter)
For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC.
The following in vitro mutagenicity tests have been conducted with clarithromycin:
All tests had negative results except the in vitro chromosome aberration test which was positive in one test and negative in another. In addition, a bacterial reverse-mutation test (Ames test) has been performed on clarithromycin metabolites with negative results.
Impairment of Fertility
Fertility and reproduction studies have shown that daily doses of up to 160 mg/kg/ to male and female rats caused no adverse effects on the estrous cycle, fertility, parturition, or number and viability of offspring. Plasma levels in rats after 150 mg/kg/day were twice the human serum levels.
Testicular atrophy occurred in rats at doses 7 times, in dogs at doses 3 times, and in monkeys at doses 8 times greater than the maximum human daily dose (on a body surface area basis).
Corneal opacity occurred in dogs at doses 12 times and in monkeys at doses 8 times greater than the maximum human daily dose (on a body surface area basis). Lymphoid depletion occurred in dogs at doses 3 times greater than and in monkeys at doses 2 times greater than the maximum human daily dose (on a body surface area basis).
NDC: 50090-4059-0 14 TABLET, FILM COATED, EXTENDED RELEASE in a BOTTLE
Provide the following instructions or information about clarithromycin extended-release tablets to patients:
Clarithromycin Extended-release Tablets, USP
* All trademark names are the property of their respective owners.
Sunshine Lake Pharma Co., Ltd.
Northern Industry Road 1#,
Song Shan Lake, DongGuan,
GuangDong Province, 523808,
Lannett Company Inc.
Philadelphia, PA 19154
clarithromycin tablet, film coated, extended release
|Labeler - A-S Medication Solutions (830016429)|
|A-S Medication Solutions||830016429||RELABEL(50090-4059) , REPACK(50090-4059)|