INDICATIONS AND USAGE Cephalexin tablets are indicated for the treatment of the following infections when caused by susceptible strains of the designated microorganisms: Respiratory tract infections caused by susceptible isolates of Streptococcus pneumoniae and Streptococcus pyogenes Otitis media due to susceptible isolates of Streptococcu pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes , and Moraxella Catarrhalis.

Skin and skin structure infections caused by susceptible isolates of the following Gram-positive bacteria: Staphylococcus aureus , and Streptococcus pyogenes .

Bone infections caused by susceptible isolates of Staphylococcus aureus and Proteus Mirabilis.

Genitourinary tract infections, including acute prostatitis, caused by susceptible isolates of Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniare.

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

WARNINGS Hypersensitivity 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 tablets.

Before therapy with cephalexin tablets 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 tablets occurs, discontinue the drug and institute appropriate treatment.

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

Direct Coomb’s 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.

Seizure 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 tablets.

Anticonvulsant therapy can be given if clinically indicated.

Prolonged 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.

ADVERSE REACTIONS 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.

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 tablets, 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.