To reduce the development of drug-resistant bacteria and maintain the effectiveness of clindamycin hydrochloride and other antibacterial drugs, clindamycin hydrochloride should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.

Clindamycin hydrochloride is the hydrated hydrochlo­ride salt of clindamycin. Clindamycin is a semisynthetic antibiotic produced by a 7(S)-chloro-substitution of the 7(R)-hydroxyl group of the parent compound lincomycin.

The chemical name for clindamycin hydrochloride is Methyl 7-chloro-6,7,8-trideoxy-6-(1-methyl-trans-4-propyl-L-2-pyrrolidinecarboxamido)-1-thio-L-threo-α-D-galacto-octopyranoside monohydrochloride.

The structural formula is represented below:

Clindamycin hydrochloride capsules, USP contain clindamycin hydro­chloride USP equivalent to 150 mg or 300 mg of clindamycin. Each capsule also contains the following inactive ingredients: lactose monohydrate, corn starch, talc, and magnesium stearate. The empty hard gelatin capsule shell consists of FD&C Blue #1, titanium dioxide, gelatin, and sodium lauryl sulphate. In addition 150 mg also contains yellow iron oxide. The capsules are printed with edible ink containing black iron oxide and shellac.

Human Pharmacology

Absorption

Pharmacokinetic studies with a 150 mg oral dose of clindamycin hydrochloride in 24 normal adult volunteers showed that clindamycin was rapidly absorbed after oral administration. An average peak serum concentration of 2.5 mcg/mL was reached in 45 minutes; serum concentrations averaged 1.51 mcg/mL at 3 hours and 0.7 mcg/mL at 6 hours. Absorption of an oral dose is virtually complete (90%), and the concomitant admin­istration of food does not appreciably modify the serum concentrations; serum concentrations have been uniform and predictable from person to person and dose to dose. Pharmacokinetic studies following multiple doses of clindamycin hydrochloride for up to 14 days show no evidence of accumulation or altered metabolism of drug. Doses of up to 2 grams of clindamycin per day for 14 days have been well tolerated by healthy volunteers, except that the incidence of gastrointestinal side effects is greater with the higher doses.

Distribution

Concentrations of clindamycin in the serum increased linearly with increased dose. Serum concentrations exceed the MIC (minimum inhibitory concentration) for most indi­cated organisms for at least six hours following adminis­tration of the usually recommended doses. Clindamycin is widely distributed in body fluids and tissues (including bones). No significant concentrations of clindamycin are attained in the cerebrospinal fluid, even in the presence of inflamed meninges.

Metabolism

In vitro studies in human liver and intestinal microsomes indicated that clindamycin is predominantly metabolized by Cytochrome P450 3A4 (CYP3A4), with minor contribution from CYP3A5, to form clindamycin sulfoxide and a minor metabolite, N-desmethylclindamycin.

Excretion

The average biological half-life is 2.4 hours. Approximately 10% of the bioactivity is excreted in the urine and 3.6% in the feces; the remainder is excreted as bioinactive metabolites.

Specific Populations

Patients with Renal/Hepatic Impairment

The elimination half-life of clindamycin is increased slightly in patients with markedly reduced renal or hepatic function. Hemodialysis and peritoneal dialysis are not effective in removing clindamycin from the serum. Dosage schedules do not need to be modified in patients with renal disease.

Geriatric Patients

Pharmacokinetic studies in elderly volunteers (61 to 79 years) and younger adults (18 to 39 years) indicate that age alone does not alter clindamycin pharmacokinetics (clearance, elimination half-life, volume of distribution, and area under the serum concentration-time curve) after IV administration of clindamycin phosphate. After oral administration of clindamycin hydrochloride, the average elimi­nation half-life is increased to approximately 4 hours (range 3.4 to 5.1 h) in the elderly compared to 3.2 hours (range 2.1 to 4.2 h) in younger adults. The extent of absorption, however, is not different between age groups and no dosage alteration is necessary for the elderly with normal hepatic function and normal (age-adjusted) renal function1.

Obese Pediatric Patients Aged 2 to Less than 18 Years and Obese Adults Aged 18 to 20 Years

An analysis of pharmacokinetic data in obese pediatric patients aged 2 to less than 18 years and obese adults aged 18 to 20 years demonstrated that clindamycin clearance and volume of distribution, normalized by total body weight, are comparable regardless of obesity.

Microbiology

Mechanism of Action

Clindamycin inhibits bacterial protein synthesis by binding to the 23S RNA of the 50S subunit of the ribosome. Clindamycin is bacteriostatic.

Resistance

Resistance to clindamycin is most often caused by modification of specific bases of the 23S ribosomal RNA. Cross-resistance between clindamycin and lincomycin is complete. Because the binding sites for these antibacterial drugs overlap, cross-resistance is sometimes observed among lincosamides, macrolides and streptogramin B. Macrolide-inducible resistance to clindamycin occurs in some isolates of macrolide-resistant bacteria. Macrolide-resistant isolates of staphylococci and beta-hemolytic streptococci should be screened for induction of clindamycin resistance using the D-zone test.

Antimicrobial Activity

Clindamycin 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):

Gram-positive bacteria

Staphylococcus aureus (methicillin-susceptible strains)
Streptococcus pneumoniae (penicillin-susceptible strains)
Streptococcus pyogenes

Anaerobic bacteria

Clostridium perfringens
Fusobacterium necrophorum
Fusobacterium nucleatum
Peptostreptococcus anaerobius
Prevotella melaninogenica

The following in vitro data are available, but their clinical significance is unknown. At least 90 percent of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for clindamycin against isolates of a similar genus or organism group. However, the efficacy of clindamycin in treating clinical infections due to these bacteria has not been established in adequate and well-controlled clinical trials.

Gram-positive bacteria

Staphylococcus epidermidis (methicillin-susceptible strains)
Streptococcus agalactiae
Streptococcus anginosus
Streptococcus mitis
Streptococcus oralis

Anaerobic bacteria

Actinomyces israelii
Clostridium clostridioforme
Eggerthella lenta
Finegoldia (Peptostreptococcus) magna
Micromonas (Peptostreptococcus) micros
Prevotella bivia
Prevotella intermedia
Cutibacterium acnes

Susceptibility Testing

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. 

Clindamycin hydrochloride capsules are indicated in the treatment of serious infections caused by susceptible anaerobic bacteria.

Clindamycin hydrochloride capsules are also indicated in the treatment of seri­ous infections due to susceptible strains of streptococci, pneumococci, and staphylococci. Its use should be reserved for penicillin-allergic patients or other patients for whom, in the judgment of the physician, a penicillin is inappropriate. Because of the risk of colitis, as described in the BOXED WARNING, before selecting clindamycin, the physician should consider the nature of the infection and the suitability of less toxic alternatives (e.g., erythromycin).

Anaerobes: Serious respiratory tract infections such as empyema, anaerobic pneumonitis, and lung abscess; serious skin and soft tissue infections; septicemia; intra-abdominal infections such as peritonitis and intra-abdominal abscess (typically resulting from anaerobic organisms resident in the normal gastroin­testinal tract); infections of the female pelvis and geni­tal tract such as endometritis, nongonococcal tubo-ovarian abscess, pelvic cellulitis, and postsurgical vaginal cuff infection.

Streptococci: Serious respiratory tract infections; seri­ous skin and soft tissue infections.

Staphylococci: Serious respiratory tract infections; serious skin and soft tissue infections.

Pneumococci: Serious respiratory tract infections.

Bacteriologic studies should be performed to deter­mine the causative organisms and their susceptibility to clindamycin.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of clindamycin hydrochloride and other antibacterial drugs, clindamycin hydrochloride 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.

Clindamycin hydrochloride capsules are contraindicated in individuals with a history of hypersensitivity to preparations containing clindamycin or lincomycin.

See BOXED WARNING

Clostridioides difficile-Associated Diarrhea

Clostridioides difficile-associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including clindamycin hydrochloride, 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 antibiotic 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 antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.

Anaphylactic and Severe Hypersensitivity Reactions

Anaphylactic shock and anaphylactic reactions have been reported (See ADVERSE REACTIONS).

Severe hypersensitivity reactions, including severe skin reactions such as toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and Stevens-Johnson syndrome (SJS), some with fatal outcome, have been reported (See ADVERSE REACTIONS).

In case of such an anaphylactic or severe hypersensitivity reaction, discontinue treatment permanently and institute appropriate therapy.

A careful inquiry should be made concerning previous sensitivities to drugs and other allergens.

Nephrotoxicity

Clindamycin is potentially nephrotoxic and cases with acute kidney injury have been reported. Consider monitoring of renal function particularly in patients with pre-existing renal dysfunction or those taking concomitant nephrotoxic drugs. In case of acute kidney injury, discontinue clindamycin hydrochloride when no other etiology is identified.

Usage in Meningitis - Since clindamycin does not diffuse adequately into the cerebrospinal fluid, the drug should not be used in the treatment of meningitis.

The following reactions have been reported with the use of clindamycin.

Infections and Infestations: Clostridioides difficile colitis

Gastrointestinal: Abdominal pain, pseudomembranous colitis, nausea, vomiting, and diarrhea (See BOXED WARNING). The onset of pseudomembranous coli­tis symptoms may occur during or after antibacterial treatment (See WARNINGS). Esophagitis and esophageal ulcer have been reported, particularly when taken in a lying position or with a small amount of water. An unpleasant or metallic taste has been reported after oral administration.

Hypersensitivity Reactions: Generalized mild to moder­ate morbilliform-like (maculopapular) skin rashes are the most frequently reported adverse reactions. Vesiculobullous rashes, as well as urticaria, have been observed during drug therapy. Severe skin reactions such as Toxic Epidermal Necrolysis, some with fatal outcome, have been reported (See WARNINGS). Cases of Acute Generalized Exanthematous Pustulosis (AGEP), erythema multiforme, some resembling Stevens-Johnson syndrome, anaphylactic shock, anaphylactic reaction and hypersensitivity have also been reported.

Skin and Mucous Membranes: Pruritus, vaginitis, angioedema and rare instances of exfoliative dermatitis have been reported (See Hypersensitivity Reactions).

Liver: Jaundice and abnormalities in liver function tests have been observed during clindamycin therapy.

Renal: Acute kidney injury (See WARNINGS).

Hematopoietic: Transient neutropenia (leukopenia) and eosinophilia have been reported. Reports of agranulocytosis and thrombocytopenia have been made. No direct etiologic relationship to concurrent clindamycin therapy could be made in any of the foregoing. 

Immune System: Drug reaction with eosinophilia and systemic symptoms (DRESS) cases have been reported.

Musculoskeletal: Cases of polyarthritis have been reported.

Significant mortality was observed in mice at an intra­venous dose of 855 mg/kg and in rats at an oral or sub­cutaneous dose of approximately 2618 mg/kg. In the mice, convulsions and depression were observed.

Hemodialysis and peritoneal dialysis are not effective in removing clindamycin from the serum.

If significant diarrhea occurs during therapy, this antibacterial drug should be discontinued (See BOXED WARNING).

Administer clindamycin hydrochloride capsules with a full glass of water (6 to 8 ounces, approximately 200 to 250 mL) and at least 30 minutes before lying down to reduce the potential for esophageal irritation (See ADVERSE REACTIONS).

Adults: Serious infections -  150 to 300 mg every 6 hours. More severe infections - 300 to 450 mg every 6 hours.

Pediatric Patients (who are able to swallow capsules): Serious infections - 8 to 16 mg/kg/day (4 to 8 mg/lb/day) divided into three or four equal doses. More severe infections - 16 to 20 mg/kg/day (8 to 10 mg/lb/day) divided into three or four equal doses. Clindamycin should be dosed based on total body weight regardless of obesity.

Clindamycin hydrochloride capsules are not suitable for pediatric patients who are unable to swallow them whole. The capsules do not provide exact mg/kg doses therefore it may be necessary to use the clindamycin palmitate oral solution in some cases.

Serious infections due to anaerobic bacteria are usu­ally treated with clindamycin injection. However, in clinically appropriate circum­stances, the physician may elect to initiate treatment or continue treatment with clindamycin hydrochloride capsules. 

In cases of β-hemolytic streptococcal infections, treat­ment should continue for at least 10 days.

Clindamycin Hydrochloride Capsules USP, 150 mg are light blue opaque/light green transparent size ‘1’ hard gelatin capsule filled with white to off-white powder and imprinted with ‘C’ on light blue opaque cap and ‘39’ on light green transparent body with black ink.

                     Bottles of 100                         NDC 65862-185-01
                     Bottles of 500                         NDC 65862-185-05

Clindamycin Hydrochloride Capsules USP, 300 mg are light blue opaque/light blue opaque size ‘0’ hard gelatin capsule filled with white to off-white powder and imprinted with ‘C’ on light blue opaque cap and ‘40’ on light blue opaque body with black ink.

                      Bottles of 16                             NDC 65862-186-16
                      Bottles of 100                           NDC 65862-186-01
                      Bottles of 500                           NDC 65862-186-05

Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].

Pharmacist: Dispense in a tight container with child-resistant closure.

1. Smith RB, Phillips JP: Evaluation of CLEOCIN HCl and CLEOCIN Phosphate in an Aged Population. Upjohn TR 8147-82-9122-021, December 1982.

Trademarks are the property of their respective owners.

Distributed by:
Aurobindo Pharma USA, Inc.
279 Princeton-Hightstown Road
East Windsor, NJ 08520

Manufactured by:
Aurobindo Pharma Limited
Hyderabad–500 032, India

Revised: 08/2024

NDC 65862-185-01
Rx only   
Clindamycin
Hydrochloride
Capsules, USP
150 mg*

AUROBINDO                           100 Capsules

NDC 65862-186-01
Rx only
Clindamycin
Hydrochloride
Capsules, USP
300 mg*
AUROBINDO             100 Capsules