CEFALEXIN

Adults The adult dosage ranges from 1-4g daily in divided doses; most infections will respond to a dosage of 500mg every 8 hours. For skin and soft tissue infections, streptococcal pharyngitis and mild, uncomplicated urinary tract infections, the usual dosage is 250mg every 6 hours or 500mg every 12 hours.

For more severe infections or those caused by less susceptible organisms, larger doses may be needed. If daily doses of cefalexin greater than 4g are required, parenteral cephalosporins, in appropriate doses, should be considered. Elderly and patients with impaired renal function As for adults although dosage should be reduced to a daily maximum of 500mg if renal function is severely impaired (glomerular filtration rate < 10ml/min).

Paediatric population The usual recommended daily dosage for children is 25-50mg/kg (10-20mg/lb) in divided doses. For skin and soft tissue infections, streptococcal pharyngitis and mild, uncomplicated urinary tract infections, the total daily dose may be divided and administered every 12 hours.

For most infections the following schedule is suggested:

Children under 5 years: 125mg every 8 hours. Children 5 years and over: 250mg every 8 hours. In severe infections, the dosage may be doubled. In the therapy of otitis media, clinical studies have shown that a dosage of 75-100mg/kg/day in 4 divided doses is required.

In the treatment of beta-haemolytic streptococcal infections, a therapeutic dose should be administered for at least 10 days. Method of administration Oral

Infections and infestations: vaginitis, genital moniliasis Blood and lymphatic system disorders: - eosinophilia, neutropenia, thrombocytopenia haemolytic anaemia and positive Coombs’ test have been reported. Psychiatric disorders: agitation, confusion, hallucinations, nervousness, sleep disturbances, restlessness Nervous system disorders: dizziness, headache, hyperactivity, hypertonia Hepatobiliary disorders; As with some penicillins and some other cephalosporins, transient hepatitis and cholestatic jaundice have been reported rarely.

Slight elevations of AST and ALT have been reported. Musculoskeletal and connective tissue disorders: arthralgia, arthritis, joint disorder Renal and urinary disorders: reversible interstitial nephritis Reproductive system and breast disorders: vaginal discharge General disorders and administration site conditions: fatigue, fever Gastrointestinal disorders: Nausea and vomiting have been reported rarely.

Dyspepsia, and abdominal pain have also occurred. Diarrhoea has been reported most frequently. It is rarely severe enough to warrant cessation of therapy. Colitis, including rare instances of symptoms of pseudomembranous colitis, has been reported either during or after antibiotic treatment.

Hypersensitivity:

Allergies have been observed in the form of rash, urticaria and angioedema, and rarely erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis. These reactions usually subside upon discontinuation of the drug. Anaphylaxis has also been reported.

Other reactions have included genital and anal pruritus.

Skin and subcutaneous tissue disorders:

Not known – Acute generalised exanthematous pustulosis (AGEP) Reporting of suspected adverse reactions Reporting suspected adverse reactions after authorization of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product.

Cefalexin should be given cautiously to patients who have shown hypersensitivity to other drugs. Cephalosporins should be given with caution to penicillin-sensitive patients, as there is some evidence of partial cross-allergenicity between the penicillins and the cephalosporins.

Patients have had severe reactions (including anaphylaxis) to both drugs. If an allergic reaction to cefalexin occurs the drug should be discontinued and the patient treated with the appropriate agents. Prolonged use of cefalexin may result in the overgrowth of non-susceptible organisms.

Careful observation of the patient is essential. If superinfection occurs during therapy, appropriate measures should be taken. Pseudomembranous colitis has been reported with virtually all broad-spectrum antibiotics, including macrolides, semi-synthetic penicillins, and cephalosporins.

It is important, therefore, to consider its diagnosis in patients who develop diarrhoea in association with the use of antibiotics. Such colitis may range in severity from mild to life-threatening. Mild cases of pseudomembranous colitis usually respond to drug discontinuance alone.

In moderate to severe cases, appropriate measures should be taken. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine. Cefalexin should be administered with caution in the presence of markedly impaired renal function.

Careful clinical and laboratory studies should be made because safe dosage may be lower than that usually recommended. Positive direct Coombs' tests have been reported during treatment with the cephalosporin antibiotics. In haematological studies, or in transfusion cross- matching procedures when antiglobulin tests are performed on the minor side, or in Coombs' testing of newborns whose mothers have received cephalosporin antibiotics before parturition, it should be recognised that a positive Coombs' test may be due to the drug.

1. 1. Cefalexin should be given cautiously to patients who have shown hypersensitivity to other drugs. Cephalosporins should be given with caution to penicillin-sensitive patients, as there is some evidence of partial cross-allergenicity between the penicillins and the cephalosporins.

Patients have had severe reactions (including anaphylaxis) to both drugs. Cefalexin is contraindicated in patients with porphyria.