Cephalexin

Cephalexin capsules USP is a cephalosporin antibacterial drug indicated for the treatment of the following infections caused by susceptible isolates of designated bacteria: Respiratory tract infection Otitis media Skin and skin structure infections Bone infections Genitourinary tract infections To reduce the development of drug-resistant bacteria and maintain the effectiveness of cephalexin capsules USP and other antibacterial drugs, cephalexin capsules USP should be used only to treat infections that are proven or strongly suspected to be caused by bacteria.

1.1Respiratory Tract Infections Cephalexin

capsules USP are indicated for the treatment of respiratory tract infections caused by susceptible isolates of Streptococcus pneumoniae and Streptococcus pyogenes .

1.2Otitis Media Cephalexin

capsules USP are indicated for the treatment of otitis media caused by susceptible isolates of Streptococcus pneumoniae , Haemophilus influenzae , Staphylococcus aureus , Streptococcus pyogenes , and Moraxella catarrhalis .

1.3Skin and Skin Structure Infections Cephalexin

capsules USP are indicated for the treatment of skin and skin structure infections caused by susceptible isolates of the following Gram-positive bacteria: Staphylococcus aureus and Streptococcus pyogenes .

1.4Bone Infections Cephalexin

capsules USP are indicated for the treatment of bone infections caused by susceptible isolates of Staphylococcus aureus and Proteus mirabilis .

1.5Genitourinary Tract Infections Cephalexin

capsules USP are indicated for the treatment of genitourinary tract infections, including acute prostatitis, caused by susceptible isolates of Escherichia coli , Proteus mirabilis , and Klebsiella pneumoniae .

1.6Usage To

reduce the development of drug-resistant bacteria and maintain the effectiveness of cephalexin capsules USP and other antibacterial drugs, cephalexin capsules USP should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information is available, this information 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.

Adults and patients at least 15 years of age The usual dose is 250 mg every 6 hours, but a dose of 500 mg every 12 hours may be administered Pediatric patients (over 1 year of age) • Otitis media: 75 to 100 mg/kg in equally divided doses every 6 hours • All other indications: 25 to 50 mg/kg given in equally divided doses • In severe infections: 50 to 100 mg/kg may be administered in equally divided doses Duration of therapy ranges from 7 to 14 days depending on the infection type and severity. Dosage adjustment is required in patients with severe and end stage renal disease (ESRD) defined as creatinine clearance below 30 mL/min.

2.1Adults and Pediatric Patients at Least

15 Years of Age The usual dose of oral cephalexin capsules USP is 250 mg every 6 hours, but a dose of 500 mg every 12 hours may be administered. Treatment is administered for 7 to 14 days. For more severe infections larger doses of oral cephalexin capsules USP may be needed, up to 4 grams daily in two to four equally divided doses.

2.2Pediatric Patients

(Over 1 year of Age) The recommended total daily dose of oral cephalexin capsules USP for pediatric patients is 25 to 50 mg/kg given in equally divided doses for 7 to 14 days. In the treatment of β-hemolytic streptococcal infections, duration of at least 10 days is recommended. In severe infections, a total daily dose of 50 to 100 mg/kg may be administered in equally divided doses.

For the treatment of otitis media, the recommended daily dose is 75 to 100 mg/kg given in equally divided doses.

2.3Dosage Adjustments in Adult and Pediatric Patients

at Least 15 Years of Age with Renal Impairment Administer the following dosing regimens for cephalexin capsules USP to patients with renal impairment . Table1. Recommended Dose Regimen for Patients with Renal Impairment Renal function Dose regimen recommendation Creatinine clearance ≥ 60 mL/min No dose adjustment Creatinine clearance 30 to 59 mL/min No dose adjustment; maximum daily dose should not exceed 1 g Creatinine clearance 15 to 29 mL/min 250 mg, every 8 hours or every 12 hours Creatinine clearance 5 to 14 mL/min not yet on dialysis There is insufficient information to make dose adjustment recommendations in patients on hemodialysis 250 mg, every 24 hours Creatinine clearance 1 to 4 mL/min not yet on dialysis 250 mg, every 48 hours or every 60 hours

Serious hypersensitivity (anaphylactic) reactions : Prior to use, inquire regarding history of hypersensitivity to beta-lactam antibacterial drugs. Discontinue the drug if signs or symptoms of an allergic reaction occur and institute supportive measures. Clostridium difficile -associated diarrhea (CDAD) : Evaluate if diarrhea occurs. Direct Coombs' Test Seroconversion : If anemia develops during or after cephalexin therapy, evaluate for drug-induced hemolytic anemia. Seizure Potential : Use lower dose in patients with renal impairment.

5.1Hypersensitivity Reactions Allergic

reactions in the form of rash, urticaria, angioedema, anaphylaxis, erythema multiforme, Stevens-Johnson syndrome, or toxic epidermal necrolysis have been reported with the use of cephalexin. Before therapy with cephalexin capsules is instituted, inquire whether the patient has a history of hypersensitivity reactions to cephalexin, cephalosporins, penicillins, or other drugs. Cross-hypersensitivity among beta-lactam antibacterial drugs may occur in up to 10% of patients with a history of penicillin allergy.

If an allergic reaction to cephalexin occurs, discontinue the drug and institute appropriate treatment.

5.2Clostridium

difficile-Associated Diarrhea Clostridium difficile -associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including cephalexin, 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.

5.3Direct Coombs’ Test Seroconversion Positive

direct Coombs' tests have been reported during treatment with the cephalosporin antibacterial drugs including cephalexin. Acute intravascular hemolysis induced by cephalexin therapy has been reported. If anemia develops during or after cephalexin therapy, perform a diagnostic work-up for drug-induced hemolytic anemia, discontinue cephalexin and institute appropriate therapy.

5.4Seizure Potential Several

cephalosporins have been implicated in triggering seizures, particularly in patients with renal impairment when the dosage was not reduced. If seizures occur, discontinue cephalexin. Anticonvulsant therapy can be given if clinically indicated.

5.5Prolonged Prothrombin Time Cephalosporins

may be associated with prolonged prothrombin time. Those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antibacterial therapy, and patients receiving anticoagulant therapy. Monitor prothrombin time in patients at risk and manage as indicated.

5.6Development of Drug-Resistant Bacteria Prescribing

cephalexin capsules 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. Prolonged use of cephalexin may result in the overgrowth of nonsusceptible organisms. Careful observation of the patient is essential.

If superinfection occurs during therapy, appropriate measures should be taken.

Patients with known hypersensitivity to cephalexin or other members of the cephalosporin class of antibacterial drugs. Cephalexin capsules are contraindicated in patients with known hypersensitivity to cephalexin or other members of the cephalosporin class of antibacterial drugs.

8.1Pregnancy Risk Summary Available

data from published epidemiologic studies and pharmacovigilance case reports over several decades with cephalosporin use, including cephalexin use in pregnant women have not established drug-associated risks of major birth defects, miscarriage, or adverse maternal or fetal outcomes . Animal reproduction studies with mice and rats using oral doses of cephalexin that are 0.6- and 1.2-times the maximum recommended human dose (MRHD) based on body surface area during organogenesis revealed no evidence of harm to the fetus . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Data Human Data: While available studies cannot definitively establish the absence of risk, published data from epidemiologic studies and postmarketing case reports over several decades have not identified a consistent association with cephalosporin use, including cephalexin, during pregnancy, and major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Available studies have methodologic limitations, including small sample size, retrospective data collection, and inconsistent comparator groups. Animal Data: In animal reproduction studies, pregnant mice and rats administered oral cephalexin doses of 250 or 500 mg/kg/day (approximately 0.6 and 1.2 times the MRHD) based on body surface area, respectively during the period of organogenesis showed no adverse effects on embryofetal development.

In a pre-and post-natal developmental toxicity study, pregnant rats that received oral doses of 250 or 500 mg/kg/day of cephalexin from Day 15 of pregnancy to litter Day 21 showed no adverse effects on parturition, litter size, or growth of offspring.

The most common adverse reactions associated with cephalexin include diarrhea, nausea, vomiting, dyspepsia and abdominal pain. To report SUSPECTED ADVERSE REACTIONS, contact Lupin Pharmaceuticals, Inc. at 1-800-399-2561 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. The following serious events are described in greater detail in the Warning and Precautions section: Hypersensitivity reactions Clostridium difficile -associated diarrhea Direct Coombs' Test Seroconversion Seizure Potential Effect on Prothrombin Activity Development of Drug-Resistant Bacteria

6.1Clinical 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. In clinical trials, the most frequent adverse reaction was diarrhea. Nausea and vomiting, dyspepsia, gastritis, and abdominal pain have also occurred.

As with penicillins and other cephalosporins, transient hepatitis and cholestatic jaundice have been reported. Other reactions have included hypersensitivity reactions, genital and anal pruritus, genital candidiasis, vaginitis and vaginal discharge, dizziness, fatigue, headache, agitation, confusion, hallucinations, arthralgia, arthritis, and joint disorder. Reversible interstitial nephritis has been reported.

Eosinophilia, neutropenia, thrombocytopenia, hemolytic anemia, and slight elevations in aspartate transaminase (AST) and alanine transaminase (ALT) have been reported. In addition to the adverse reactions listed above that have been observed in patients treated with cephalexin, the following adverse reactions and other altered laboratory tests have been reported for cephalosporin class antibacterial drugs: Other Adverse Reactions Fever, colitis, aplastic anemia, hemorrhage, renal dysfunction, and toxic nephropathy. Altered Laboratory Tests Prolonged prothrombin time, increased blood urea nitrogen (BUN), increased creatinine, elevated alkaline phosphatase, elevated bilirubin, elevated lactate dehydrogenase (LDH), pancytopenia, leukopenia, and agranulocytosis.