CEPHACOR

What it is

Cephalexin monohydrate is a semisynthetic cephalosporin antibiotic for oral administration. In vitro tests demonstrate that the cephalosporins are bactericidal because of their inhibition of cell-wall synthesis. CEPHACOR is available as 250 mg and 500 mg capsules containing cephalexin monohydrate.

Approved indications

Cephalexin is indicated in the treatment of the following infections when caused by susceptible strains of the designated microorganisms: — Respiratory tract infections caused by S. pneumoniae and group A beta-haemolytic streptococci — Bacterial sinusitis caused by streptococci, S. pneumoniae and S. aureus (methicillin-sensitive only) — Otitis media due to S. pneumoniae and staphylococci — Skin and soft-tissue infections caused by staphylococci and/or streptococci — Genitourinary tract infections, including acute prostatitis caused by E. coli, P. mirabilis, and Klebsiella sp.

Dosing overview

The adult dosage ranges from 1 to 4 g daily in divided doses, with the usual adult dose being 250 mg every 6 hours. For streptococcal pharyngitis or tonsillitis, mild uncomplicated urinary tract infections, and skin and soft tissue infections, a dosage of 500 mg may be administered every 12 hours. The usual recommended daily dosage for children is 25 to 50 mg/kg in divided doses. In the therapy of otitis media, a dosage of 75 to 100 mg/kg/day in 4 divided doses is recommended. CEPHACOR 250 mg and 500 mg are administered orally.

Key safety warnings

Before initiating therapy with cephalexin, every attempt should be made to determine if the patient has had previous hypersensitivity reactions to the cephalosporins, penicillins or other drugs. This product should be given cautiously to penicillin-sensitive patients. There is some clinical and laboratory evidence of partial cross-allergenicity of the penicillins and the cephalosporins, and patients have been reported to have had severe reactions including anaphylaxis to both drugs. Antibiotic-associated pseudomembranous colitis has been reported with virtually all broad-spectrum antibiotics. A toxin produced with Clostridium difficile appears to be the primary cause. The severity of the colitis may range from mild to life-threatening. It is important to consider the diagnosis in patients who develop diarrhoea or colitis in association with antibiotic use, which may occur up to several weeks after cessation of antibiotic therapy. There have been reports of neurotoxicity associated with cephalosporin treatment, with symptoms including encephalopathy, seizures and/or myoclonus. Risk factors for developing neurotoxicity include being elderly, renal impairment, central nervous system disorders and intravenous administration. Severe cutaneous adverse reactions, such as Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms, and acute generalised exanthematous pustulosis, have been reported in patients taking beta-lactam antibiotics. When such reactions are suspected, cephalexin should be discontinued immediately and an alternative treatment should be considered.

Contraindications

Cephalexin is contraindicated in patients with known allergy to the cephalosporin group of antibiotics or who have previously experienced a major allergy to penicillin.

Key safety warnings

Cephalexin should be administered with caution in the presence of markedly impaired renal function, and careful clinical and laboratory studies should be made because safe dosage may be lower than that usually recommended. Cephalexin is excreted in milk. Caution should be exercised when cephalexin is administered to a nursing woman, and alternative feeding arrangements for the infant should be considered.

Regulatory history

CEPHACOR cefalexin 500 mg capsules and 250 mg capsules were first listed on the ARTG on 2 October 2013.