KEFLEX ®

Composition | Properties | Indications | Dosage & Administation | Contraindications | Precautions | Side Effects | Presentations

DESCRIPTION
Keflex (cephalexin monohydrate, LILLY) is a semisynthetic cephalosporin antibiotic for oral administration. It is 7- (D-a-amino - a - phenylacetamido) - 3 - methyl - 3 - cephem - 4 - carboxylic acid, monohydrate.

PRESENTATION
Keflex 500mg: - tablets each equivalent to 500mg cephalexin. Keflex 250mg: - Capsules each equivalent to 250mg cephalexin. Keflex 250mg: - granules to obtain 100ml suspensions, equivalent to 250mg cephalexin per tea-spoon (=5ml). Keflex 125mg: - granules to obtain 100ml suspensions, equivalent to 125mg cephalexin per tea-spoon (=5ml).

INDICATIONS
Cephalexin is indicated in the treatment of the following infections due to susceptible micro-organisms: respiratory tract infections; skin and soft tissue infections; bone and joint infections; genito-urinary infections, including acute prostatitis and dental infections. Cephalexin is active against the following organisms in vitro : Beta-haemolytic streptococci; staphylococci, including coagulase-positive, coagulase-negative and penicillinase - producing strains; streptococcus pneumoniae; Escherichia coli; Proteus mirabilis; Klebsiella species; Branhamella catarrhalis. Most strains of enterococci (Streptococcus faecalis) and a few strains of staphylococci are resistant to cephalexin. It is not active against most strains of Enterobacter species, morganella morganii and Pr. vulgaris. It has no activity against Pseudomonas or Herellea species. When tested by in vitro methods, staphylococci exhibit cross-resistance between cephalexin and methicillin - type antibiotics.

DOSAGE AND ADMINISTRATION
Keflex is administered orally. 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 Keflex greater than 4g are required, parenteral cephalosporins, in appropriate doses, should be considered. The elderly and patients with impaired renal function: As for adults. Reduce dosage if renal function is markedly impaired (see PRECAUTIONS). Children: The usual recommended daily dosage for children is 25-50mg/kg 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 to 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.
CHILDREN : (over 2 years): 2.5-5 ml, 2-4 times daily according to age.

CONTRAINDICATIONS
Cephalexin is contra-indicated in patients with known allergy to the cephalosporin group of antibiotics.

WARNINGS
Before instituting therapy with cephalexin, every effort should be made to determine whether the patient has had previous hypersensitivity reactions to the cephalosporins, penicillins or other drugs. Cephalexin should be given cautiously to penicillin-sensitive patients. There is some clinical and laboratory evidence of partial cross-allergenicity of the penicillins and cephalosporins. Patients have had severe reactions (including anaphylaxis) to both drugs. Pseudomembranous colitis has been reported with virtually all broad-spectrum antibiotics, including macrolides, semisynthetic 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. Usage in pregnancy: Although laboratory and clinical studies have shown no evidence of teratogenicity, caution should be exercised when prescribing for the pregnant patient. Usage in nursing mothers: The excretion of cephalexin in human breast milk increased up to 4 hours following a 500mg dose. The drug reached a maximum level of 4 micrograms/ml, then decreased gradually and had disappeared 8 hours after administration. Caution should be exercised when cephalexin is administered to a nursing woman

PRECAUTIONS
If an allergic reaction to cephalexin occurs the drug should be discontinued and the patient treated with the appropriate agents. Prolonged use of cephalexin 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. Cephalexin 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 procedure 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. A false positive reaction for glucose in the urine may occur with Benedict's or Fehling's solutions or with copper sulphate test tablets.

ADVERSE REACTIONS
Gastro-intestinal - Symptoms of pseudomembranous colitis may appear either during or after antibiotic treatment. Nausea and vomiting have been reported rarely. The most frequent side-effect has been diarrhoea. It was very rarely severe enough to warrant cessation of therapy. Dyspepsia and abdominal pain have also occurred. As with some penicillins and some other cephalosporins, transient hepatitis and cholestatic jaundice have been reported rarely. Hypersensitivity - Allergic reactions have been observed in the form of rash, urticaria, angioedema, and rarely erythema multiforme, stevens-Johnson syndrome and toxic epidermal necrolysis. These reactions usually subsided upon discontinuation of the drug, although in some cases supportive therapy may be necessary. Anaphylaxis has also been reported. Other - These have included 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 rarely. Eosinophilia, neutropenia, thrombocytopenia, and slight elevations in AST and ALT have been reported.

OVERDOSAGE:
Treatment of overdosage - Symptoms of oral overdose may include nausea, vomiting, epigastric distress, diarrhoea and haematuria. In the event of severe overdosage, general supportive care is recommended, including close clinical and laboratory monitoring of haematological, renal and hepatic functions, and coagulation status until the patient is stable. Forced diuresis, peritoneal dialysis, haemodialysis, or charcoal haemoperfusion have not been established as beneficial for an overdose of cephalexin. It would be extremely unlikely that one of these procedures would be indicated. Unless 5 to 10 times the normal total daily dose has been ingested, gastro-intestinal decontamination should not be necessary. There have been reports of haematuria without impairment of renal function in children accidentally ingesting more than 3.5g of cephalexin in a day. Treatment has been supportive (fluids) and no sequelae have been reported.

STORAGE
Tablets + Capsules - Keep containers tightly closed. Suspension - After mixing, Keflex suspensions should be stored in a cool place (6_ - 15_C) or in a refrigerator (0_ - 6_C) and be used within 10 days. Where dilution is unavoidable, syrup BP should be used after the suspension has been prepared according to the manufacturer's instructions.