1.1 Septicemia

Septicemia (including bacteremia) caused by β‑lactamase–producing isolates of Klebsiella spp.*, Escherichia coli*, Staphylococcus aureus*, or Pseudomonas aeruginosa* (or other Pseudomonas species*)

1.2 Lower Respiratory Infections

Lower respiratory infections caused by β‑lactamase–producing isolates of S. aureus, Haemophilus influenzae*, or Klebsiella spp.*

1.3 Bone and Joint Infections

Bone and joint infections caused by β‑lactamase–producing isolates of S. aureus

1.4 Skin and Skin Structure Infections

Skin and skin structure infections caused by β‑lactamase–producing isolates of S. aureus, Klebsiella spp.*, or E. coli*

1.5 Urinary Tract Infections

Urinary tract infections (complicated and uncomplicated) caused by β‑lactamase–producing isolates of E. coli, Klebsiella spp., P. aeruginosa* (or other Pseudomonas spp.*), Citrobacter spp.*, Enterobacter cloacae*, Serratia marcescens*, or S. aureus*

1.6 Gynecologic Infections

Endometritis caused by β‑lactamase–producing isolates of Prevotella melaninogenicus*, Enterobacter spp. (including E. cloacae*), E. coli, Klebsiella pneumoniae*, S. aureus, or Staphylococcus epidermidis

1.7 Intra-abdominal Infections

Peritonitis caused by β‑lactamase–producing isolates of E. coli, K. pneumoniae, or Bacteroides fragilis* group

* Efficacy for this organism in this organ system was studied in fewer than 10 infections.

1.8 Usage

To reduce the development of drug‑resistant bacteria and maintain the effectiveness of TIMENTIN and other antibacterial drugs, TIMENTIN should be used only to treat 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.

2.1 Adults

The usual recommended dosage for systemic and urinary tract infections for adults is 3.1 grams of TIMENTIN (3 grams ticarcillin and 100 mg clavulanic acid) given every 4 to 6 hours.

For gynecologic infections, TIMENTIN should be administered as follows (based on ticarcillin content): Moderate infections, 200 mg/kg/day in divided doses every 6 hours; severe infections, 300 mg/kg/day in divided doses every 4 hours.

For patients weighing less than 60 kg, the recommended dosage is 200 to 300 mg/kg/day given in divided doses every 4 to 6 hours.

The duration of therapy depends upon the severity of infection. The usual duration is 10 to 14 days; however, in difficult and complicated infections, more prolonged therapy may be required.

2.2 Pediatric Patients (≥3 Months of Age)

Patients <60 kg: Mild to moderate infections, 200 mg/kg/day based on ticarcillin content in divided doses every 6 hours; severe infections, 300 mg/kg/day in divided doses every 4 hours.

Patients ≥60 kg: Mild to moderate infections, 3.1 grams every 6 hours; severe infections, 3.1 grams every 4 hours.

2.3 Renal Impairment

For patients with renal insufficiency, an initial loading dose of 3.1 grams should be followed by doses based on creatinine clearance and type of dialysis as indicated in Table 1.

a To calculate creatinine clearance1 from a serum creatinine value use the following formula:

Ccr = (140–Age) (weight in kg)/72 x Scr (mg/100 mL)

This is the calculated creatinine clearance for adult males; for females it is 15% less.

b Based on ticarcillin content.

2.4 Administration and Directions for Use

TIMENTIN should be administered by intravenous infusion over a 30-minute period.

Directions for Reconstitution and Further Dilution: 3.1‑gram Glass Vials: The 3.1‑gram vial should be reconstituted by adding approximately 13 mL of Sterile Water for Injection, USP, or Sodium Chloride Injection, USP, and shaking well. When dissolved, the concentration of ticarcillin will be approximately 200 mg/mL with a corresponding concentration of 6.7 mg/mL for clavulanic acid. The color of reconstituted solutions of TIMENTIN normally ranges from light to dark yellow, depending on concentration, duration, and temperature of storage.

The dissolved drug should be further diluted to desired volume using the recommended solution listed under Stability [see Dosage and Administration (2.5)] to a concentration between 10 mg/mL to 100 mg/mL.

Pharmacy Bulk Package: The container closure may be penetrated only one time utilizing a suitable sterile transfer device or dispensing set that allows measured distribution of the contents. A sterile substance that must be reconstituted prior to use may require a separate closure entry.

Restrict use of Pharmacy Bulk Packages to an aseptic area such as a laminar flow hood.

Reconstituted contents of the vial should be withdrawn immediately. However, if this is not possible, aliquoting operations must be completed within 4 hours of reconstitution. Discard the reconstituted stock solution 4 hours after initial entry.

Add 76 mL of Sterile Water for Injection, USP, or Sodium Chloride Injection, USP, to the 31‑gram Pharmacy Bulk Package and shake well. For ease of reconstitution, the diluent may be added in 2 portions. Each 1 mL of the resulting concentrated stock solution contains approximately 300 mg of ticarcillin and 10 mg of clavulanic acid.

The desired dosage should be withdrawn from the stock solution and further diluted to desired volume using the recommended solution listed under Stability [see Dosage and Administration (2.5)] to a concentration between 10 mg/mL to 100 mg/mL.

Directions for Intravenous Infusion: After reconstitution and further dilution and prior to administration, TIMENTIN should be inspected visually for particulate matter. If particulate matter is present, the solution should be discarded.

The solution of reconstituted drug may be administered over a 30-minute period by direct infusion or through a Y‑type intravenous infusion set. If this method of administration is used, it is advisable to temporarily discontinue the administration of any other solutions during the infusion of TIMENTIN.

When TIMENTIN is given in combination with another antimicrobial, such as an aminoglycoside, each drug should be given separately in accordance with the recommended dosage and routes of administration for each drug [see Drug Interactions (7.1)].

GALAXY® Container (PL 2040 Plastic): Prior to administration, TIMENTIN should be inspected visually for particulate matter. If particulate matter is present, the solution should be discarded.

Caution: Do not use plastic containers in series connections. Such use could result in an embolism due to residual air being drawn from the primary container before administration of the fluid from the secondary container is completed.

Preparation for Administration: See How Supplied/Storage and Handling (16) for thawing and handling instructions:

•

Suspend the container from eyelet support.

•

Remove protector from outlet port at bottom of container.

•

Attach administration set. Refer to complete directions accompanying set.

2.5 Stability

NOTE: TIMENTIN is incompatible with Sodium Bicarbonate.

3.1‑gram Glass Vials: The concentrated stock solution at 200 mg/mL is stable for up to 6 hours at room temperature 21° to 24°C (70° to 75°F) or up to 72 hours under refrigeration 4°C (40°F).

If the concentrated stock solution (200 mg/mL) is held for up to 6 hours at room temperature 21° to 24°C (70° to 75°F) or up to 72 hours under refrigeration 4°C (40°F) and further diluted to a concentration between 10 mg/mL and 100 mg/mL with any of the diluents listed below, then the following stability periods apply.

If the concentrated stock solution (200 mg/mL) is stored for up to 6 hours at room temperature and then further diluted to a concentration between 10 mg/mL and 100 mg/mL, solutions of Sodium Chloride Injection, USP, and Lactated Ringer’s Injection, USP, may be stored frozen –18°C (0°F) for up to 30 days. Solutions prepared with Dextrose Injection 5%, USP, may be stored frozen –18°C (0°F) for up to 7 days. All thawed solutions should be used within 8 hours or discarded. Once thawed, solutions should not be refrozen.

Unused solutions must be discarded after the time periods listed above.

Pharmacy Bulk Package: Aliquots of the reconstituted stock solution at 300 mg/mL are stable for up to 6 hours between 21° and 24°C (70° and 75°F) or up to 72 hours under refrigeration 4°C (40°F). The reconstituted stock solution should be held under refrigeration 4°C (40°F).

If the aliquots of the reconstituted stock solution (300 mg/mL) are held up to 6 hours between 21° and 24°C (70° and 75°F) or up to 72 hours under refrigeration 4°C (40°F) and further diluted to a concentration between 10 mg/mL and 100 mg/mL with any of the diluents listed below, then the following stability periods apply.

If an aliquot of concentrated stock solution (300 mg/mL) is stored for up to 6 hours between 21° and 24°C (70° and 75°F) and then further diluted to a concentration between 10 mg/mL and 100 mg/mL, solutions of Sodium Chloride Injection, USP, Lactated Ringer’s Injection, USP, and Sterile Water for Injection, USP, may be stored frozen –18°C (0°F) for up to 30 days. Solutions prepared with Dextrose Injection 5%, USP, may be stored frozen –18°C (0°F) for up to 7 days. All thawed solutions should be used within 8 hours or discarded. Once thawed, solutions should not be refrozen.

Unused solutions must be discarded after the time periods listed above.

GALAXY Container (PL 2040 Plastic): Do not add supplementary medication to the container. The thawed solution is stable for 24 hours at room temperature 22°C (72°F) or for 7 days under refrigeration at 4°C (39°F).

5.1 Anaphylactic Reactions

Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving beta-lactam antibacterials. These reactions are more likely to occur in individuals with a history of penicillin hypersensitivity and/or a history of sensitivity to multiple allergens. Before initiating therapy with TIMENTIN, inquire about previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens. If an allergic reaction occurs, discontinue TIMENTIN and institute appropriate therapy.

5.2 Clostridium difficile Associated Diarrhea

Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including TIMENTIN, 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 2 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.

5.3 Convulsions

Patients may experience convulsions when the dose of TIMENTIN exceeds the recommended dose, especially in the presence of impaired renal function [see Adverse Reactions (6.2), Overdosage (10)].

5.4 Risk of Bleeding

Some patients receiving β-lactam antibacterials have experienced bleeding associated with abnormalities in coagulation tests. These adverse reactions are more likely to occur in patients with renal impairment. If bleeding manifestations appear, treatment with TIMENTIN should be discontinued and appropriate therapy instituted.

5.5 Potential for Microbial Overgrowth or Bacterial Resistance

The possibility of superinfections with fungal or bacterial pathogens should be considered during therapy. If superinfections occur, appropriate measures should be taken.

5.6 Development of Drug-Resistant Bacteria

Prescribing TIMENTIN in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug‑resistant bacteria.

5.7 Interference with Laboratory Tests

High urine concentrations of ticarcillin may produce false-positive protein reactions (pseudoproteinuria) [see Drug Interactions (7.4)].

Clavulanic acid may cause a nonspecific binding of IgG and albumin by red cell membranes, leading to a false-positive Coombs test [see Drug Interactions (7.4)].

5.8 Electrolyte Imbalance

Hypokalemia has been reported during treatment with TIMENTIN. Serum potassium should be monitored in patients with fluid and electrolyte imbalance and in patients receiving prolonged therapy. The theoretical sodium content is 4.51 mEq (103.6 mg) per gram of TIMENTIN. This should be considered when treating patients requiring restricted salt intake.

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Adverse reactions occurring in ≥1% of 867 patients receiving TIMENTIN 3.1 grams in clinical studies included rash, nausea, diarrhea, and phlebitis at the injection site. The most common laboratory abnormalities (≥3%) were elevations in eosinophils, serum aspartate aminotransferase (AST), and serum alanine aminotransferase (ALT).

Available safety data for pediatric patients treated with TIMENTIN demonstrate a similar adverse event profile to that observed in adult patients.

6.2 Postmarketing Experience

In addition to adverse reactions reported from clinical trials, the following adverse reactions have been identified during postmarketing use of TIMENTIN. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These adverse reactions have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to TIMENTIN.

Hypersensitivity Reactions: Skin rash, pruritus, urticaria, arthralgia, myalgia, drug fever, chills, chest discomfort, anaphylactic reactions, and bullous reactions (including erythema multiforme, toxic epidermal necrolysis, and Stevens‑Johnson syndrome).

Central Nervous System: Headache, giddiness, neuromuscular hyperirritability, or convulsive seizures.

Gastrointestinal Disturbances: Disturbances of taste and smell, stomatitis, flatulence, nausea, vomiting and diarrhea, epigastric pain, and pseudomembranous colitis have been reported. Onset of pseudomembranous colitis symptoms may occur during or after antibacterial treatment [see Warnings and Precautions (5.2)].

Hemic and Lymphatic Systems: Thrombocytopenia, leukopenia, neutropenia, eosinophilia, reduction of hemoglobin or hematocrit, and prolongation of prothrombin time and bleeding time.

Abnormalities of Hepatic Function Tests: Elevation of AST, ALT, serum alkaline phosphatase, serum LDH, and serum bilirubin. There have been reports of transient hepatitis and cholestatic jaundice, as with some other penicillins and some cephalosporins.

Renal and Urinary Effects: Hemorrhagic cystitis, elevation of serum creatinine and/or BUN, hypernatremia, reduction in serum potassium, and uric acid.

Local Reactions: Pain, burning, swelling, and induration at the injection site and thrombophlebitis with intravenous administration.

7.1 Aminoglycosides

The mixing of TIMENTIN with an aminoglycoside in solutions for parenteral administration can result in substantial inactivation of the aminoglycoside.

7.2 Probenecid

Probenecid interferes with the renal tubular secretion of ticarcillin, thereby increasing serum concentrations and prolonging serum half‑life of ticarcillin. Probenecid does not affect the serum levels of clavulanic acid.

7.3 Oral Contraceptives

Ticarcillin disodium/clavulanate potassium may affect the gut flora, leading to lower estrogen reabsorption and reduced efficacy of combined oral estrogen/progesterone contraceptives.

7.4 Effects on Laboratory Tests

High urine concentrations of ticarcillin may produce false‑positive protein reactions (pseudoproteinuria) with certain methods. The bromphenol blue reagent strip test has been reported to be a reliable method for testing protein reactions [see Warnings and Precautions (5.7)].

Clavulanic acid in TIMENTIN may cause a nonspecific binding of IgG and albumin by red cell membranes, leading to a false‑positive Coombs test. A positive Coombs test should be interpreted with caution during treatment with TIMENTIN [see Warnings and Precautions (5.7)].

8.1 Pregnancy

Pregnancy Category B.

Reproduction studies have been performed in rats given doses up to 1,050 mg/kg/day (approximately half of the recommended human dose based on body surface area) and have revealed no evidence of harm to the fetus due to TIMENTIN. There are, however, no adequate and well‑controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

8.3 Nursing Mothers

It is not known whether ticarcillin or clavulanic acid is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when TIMENTIN is administered to a nursing woman.

8.4 Pediatric Use

The safety and effectiveness of TIMENTIN have been established in the age group of 3 months to 16 years. Use of TIMENTIN in these age groups is supported by evidence from adequate and well‑controlled studies of TIMENTIN in adults with additional efficacy, safety, and pharmacokinetic data from both comparative and non‑comparative studies in pediatric patients. There are insufficient data to support the use of TIMENTIN in pediatric patients under 3 months of age.

If meningitis is suspected or documented, an alternative agent with demonstrated clinical efficacy in this setting should be used.

8.5 Geriatric Use

An analysis of clinical studies of TIMENTIN was conducted to determine whether subjects aged 65 and older respond differently from younger subjects. Of the 1,078 subjects treated with at least one dose of TIMENTIN, 67.5% were <65 years old, and 32.5% were ≥65 years old. No overall differences in safety or efficacy were observed between older and younger subjects, and other reported clinical experience have not identified differences in responses between the elderly and younger patients, but a greater sensitivity of some older individuals cannot be ruled out.

This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function [see Dosage and Administration (2.3)].

TIMENTIN contains 103.6 mg (4.51 mEq) of sodium per gram of TIMENTIN. At the usual recommended doses, patients would receive between 1,285 and 1,927 mg/day (56 and 84 mEq) of sodium. The geriatric population may respond with a blunted natriuresis to salt loading. This may be clinically important with regard to such diseases as congestive heart failure.

8.6 Renal Impairment

Ticarcillin is predominantly excreted by the kidney [see Clinical Pharmacology (12.3)]. Dosage adjustments should be made for patients with renal impairment [see Dosage and Administration (2.3)].

12.1 Mechanism of Action

TIMENTIN is an antibacterial drug [see Clinical Pharmacology (12.4)].

12.3 Pharmacokinetics

Absorption: After an intravenous infusion (30 minutes) of 3.1 grams of TIMENTIN, peak serum concentrations of both ticarcillin and clavulanic acid were attained immediately after completion of the infusion. Ticarcillin serum levels were similar to those produced by the administration of equivalent amounts of ticarcillin alone with a mean peak serum level of 324 mcg/mL. The corresponding mean peak serum level for clavulanic acid was 8 mcg/mL. (See Table 2.)

The mean area under the serum concentration curve was 485 mcg•hr/mL for ticarcillin and 8.2 mcg•hr/mL for clavulanic acid.

Distribution: Ticarcillin has been found to be approximately 45% bound to human serum protein and clavulanic acid approximately 25% bound. Ticarcillin can be detected in tissues and interstitial fluid following parenteral administration.

Distribution of ticarcillin into bile and pleural fluid has been demonstrated. The results of experiments involving the administration of clavulanic acid to animals suggest that this compound, like ticarcillin, is well distributed in body tissues.

Elimination: Approximately 60% to 70% of ticarcillin and approximately 35% to 45% of clavulanic acid are excreted unchanged in urine during the first 6 hours after administration of a single dose of TIMENTIN to normal volunteers with normal renal function. Two hours after an intravenous injection of 3.1 grams of TIMENTIN, concentrations of ticarcillin in urine generally exceed 1,500 mcg/mL. The corresponding concentrations of clavulanic acid in urine generally exceed 40 mcg/mL. By 4 to 6 hours after injection, the urine concentrations of ticarcillin and clavulanic acid usually decline to approximately 190 mcg/mL and 2 mcg/mL, respectively.

The mean serum half‑life of both ticarcillin and clavulanic acid in healthy volunteers was 1.1 hours.

Pediatrics: In pediatric patients receiving approximately 50 mg/kg of TIMENTIN (30:1 ratio ticarcillin to clavulanate), mean ticarcillin serum half‑lives were 4.4 hours in neonates (n = 18) and 1.0 hour in infants and children (n = 41). The corresponding clavulanate serum half‑lives averaged 1.9 hours in neonates (n = 14) and 0.9 hour in infants and children (n = 40). Area under the serum concentration time curves averaged 339 mcg•hr/mL in infants and children (n = 41), whereas the corresponding mean clavulanate area under the serum concentration time curves was approximately 7 mcg•hr/mL in the same population (n = 40).

Renal Impairment: An inverse relationship exists between the serum half‑life of ticarcillin and creatinine clearance. The half‑life of ticarcillin in patients with renal failure is approximately 13 hours. The dosage of TIMENTIN need only be adjusted in cases of severe renal impairment [see Dosage and Administration (2.3)].

Ticarcillin may be removed from patients undergoing dialysis; the actual amount removed depends on the duration and type of dialysis.

12.4 Microbiology

Mechanism of Action: Ticarcillin disrupts bacterial cell wall development by inhibiting peptidoglycan synthesis and/or by interacting with penicillin‑binding proteins.

Ticarcillin is susceptible to degradation by β‑lactamases, so the spectrum of activity does not normally include organisms which produce these enzymes.

Clavulanic acid is a β‑lactam, structurally related to the penicillins, which inactivates some β‑lactamase enzymes that are commonly found in bacteria resistant to penicillins and cephalosporins. In particular, it has good activity against the clinically important plasmid‑mediated β‑lactamases frequently responsible for transferred drug resistance.

The formulation of ticarcillin with clavulanic acid in TIMENTIN protects ticarcillin from degradation by β‑lactamase enzymes, effectively extending the antibacterial spectrum of ticarcillin to include many bacteria normally resistant to ticarcillin and other β‑lactam antibacterials.

Interaction With Other Antimicrobials: In vitro synergism between TIMENTIN and gentamicin, tobramycin, or amikacin against multi-resistant isolates of Pseudomonas aeruginosa has been demonstrated.

Ticarcillin/clavulanic acid has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections [see Indications and Usage (1)].

Susceptibility to ticarcillin/clavulanic acid will vary with geography and time; local susceptibility data should be consulted, if available.

Gram-positive bacteria

Staphylococcus aureus (methicillin-susceptible isolates only)

Staphylococcus epidermidis (methicillin-susceptible isolates only)

Gram-negative bacteria

Citrobacter spp.a

Enterobacter spp.a

E. cloacaea

Escherichia colia

Haemophilus influenzaeb

Klebsiella spp.a

K. pneumoniaea

Pseudomonas spp.a

P. aeruginosaa

Serratia marcescensa

Anaerobic bacteria

Bacteroides fragilis group

Prevotella melaninogenicus

a Some extended spectrum β‑lactamase (ESBL)–producing isolates are resistant to ticarcillin/clavulanic acid. Most carbapenemase-producing isolates are resistant to ticarcillin/clavulanic acid.

b β‑lactamase‑negative, ampicillin‑resistant (BLNAR) isolates of H. influenzae must be considered resistant to ticarcillin/clavulanic acid.

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 ticarcillin/clavulanic acid. However, the efficacy of ticarcillin/clavulanic acid in treating clinical infections due to these bacteria have not been established in adequate and well-controlled clinical trials.

Gram-positive bacteria

Staphylococcus saprophyticus (methicillin-susceptible isolates only)

Streptococcus agalactiae (Group B)

Streptococcus bovis

Streptococcus pneumoniae (penicillin-susceptible isolates only)

Streptococcus pyogenes

Streptococcus spp. viridans group (penicillin-susceptible isolates only)

Gram-negative bacteria

Moraxella catarrhalis

Pasteurella multocida

Anaerobic bacteria

Clostridium spp.

C. perfringens

C. difficile

C. sporogenes

C. ramosum

C. bifermentans

Eubacterium spp.

Fusobacterium spp.

F. nucleatum

F. necrophorum

Peptostreptococcus spp.

Veillonella spp.

Susceptibility Testing: When available, the clinical microbiology laboratory should provide the results of in vitro susceptibility test results for antimicrobial drug products used in local hospitals and practice areas to the physician as periodic reports that describe the susceptibility profile of nosocomial and community-acquired pathogens. These reports should aid the physician in selecting an antibacterial drug product for treatment.

Dilution Techniques: Quantitative methods are used to determine antimicrobial minimum inhibitory concentrations (MICs). These MICs provide estimates of the susceptibility of bacteria to antimicrobial compounds. The MICs should be determined using a standardized test method2,4 (broth and/or agar). The MIC values should be interpreted according to criteria provided in Table 3.

Diffusion Techniques: Quantitative methods that require measurement of zone diameters can also provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. The zone size provides an estimate of the susceptibility of bacteria to antimicrobial compounds. The zone size should be determined using a standardized test method.3,4 These procedures use paper disks impregnated with 85 mcg of ticarcillin/clavulanate potassium (75 mcg ticarcillin plus 10 mcg clavulanate potassium) to test the susceptibility of bacteria to ticarcillin/clavulanic acid. The disc diffusion interpretive criteria are provided in Table 3.

Anaerobic Techniques: For anaerobic bacteria, susceptibility to ticarcillin/clavulanic acid can be determined by standardized test methods.4,5 The MIC values obtained should be interpreted according to the criteria in Table 3.

Susceptibility of staphylococci to ticarcillin/clavulanate may be deduced by testing penicillin and either oxacillin or cefoxitin.4

A report of “Susceptible” indicates the antimicrobial is likely to inhibit growth of the pathogen if the antimicrobial compound reaches the concentrations at the infection site necessary to inhibit growth of the pathogen. A report of “Intermediate” indicates that the result should be considered equivocal, and, if the bacterium is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. This category implies possible clinical applicability in body sites where the drug product is physiologically concentrated or in situations where a high dosage of the drug product can be used. This category also provides a buffer zone that prevents small uncontrolled technical factors from causing major discrepancies in interpretation. A report of “Resistant” indicates that the antimicrobial is not likely to inhibit growth of the pathogen if the antimicrobial compound reaches the concentrations usually achievable at the infection site; other therapy should be selected.

Quality Control: Standardized susceptibility test procedures require the use of laboratory controls to monitor and ensure the accuracy and precision of supplies and reagents used in the assay, and the techniques of the individual performing the tests.2,3,4,5 Standard ticarcillin/clavulanic acid powder should provide the following range of MIC values noted in Table 4. For the diffusion technique using the 85 mcg of ticarcillin/clavulanate potassium (75 mcg ticarcillin plus 10 mcg clavulanate potassium), the criteria in Table 4 should be achieved.

ATCC = American Type Culture Collection

MIC = Minimum Inhibitory Concentration

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Long‑term studies in animals have not been performed to evaluate carcinogenic potential. Results from in vitro assays in bacteria (Ames tests), yeast, and human lymphocytes, and in vivo in mouse bone marrow (micronucleus test) indicate TIMENTIN is without genotoxic potential.