Cefalexin

FORMULATION
Each capsule contains:
Cefalexin Monohydrate equivalent to
Cefalexin             …………………………………    500 mg

PHARMACOKINETICS
Cefalexin is almost completely absorbed from the gastrointestinal tract and produces a peak plasma concentration of about 18 micrograms /ml 1 hour after a 500 mg oral dose, if Cefalexin is taken with food, absorption may be delayed but the total amount absorbed is not appreciably altered. Up to 15% of a dose is bound to plasma proteins. The plasma half-life is about I hour; it increases with reduced renal function. Cefalexin is widely distributed in the body but does not enter the CSF in significant quantities. It crosses the placenta and small quantities are found in breastmilk. Cefalexin is not metabolised. About 80% or more of a dose is excreted unchanged in the urine in the first 6 hours by glomerular filtration and tubular secretion; urinary concentrations greater than I mg / ml have been achieved after a dose of 500 mg. Probenecid delays urinary excretion. Therapeutically effective concentrations may be found in the bile and some may be excreted by this route. Cefalexin is removed by haemodialysis and peritoneal
dialysis.

INDICATIONS
Cefalexin is a first-generation cephalosporin antibacterial, used for the treatment of susceptible infections including those of respiratory, urinary tracts, skin and soft tissue infections.

DRUG INTERACTIONS
Metformin — In healthy subjects given single 500 mg doses of Cefalexin and metformin, plasma metformin mean Cmax and AUC increased by an average of 34% and 24%, respectively, and metformin mean renal clearance decreased by 14%. No information is available about the interaction of Cefalexin and metformin following multiple doses of either drug. Although not observed in this study, adverse effects could potentially arise from co-administration of Cefalexin and metformin by inhibition of tubular secretion via organic cationic transporter systems. Accordingly, careful patient monitoring and dose adjustment of metformin is recommended in patients concomitantly taking Cefalexin and metformin. Probenecid — As with other ß-lactams, the renal excretion of Cefalexin is inhibited by probenecid.

DRUG 1 LABORATORY TEST INTERACTIONS
As a result of administration of Cefalexin, a false-positive reaction for glucose in the urine may occur. This has been observed with Benedict’s and Fehling’s solutions and also with Clinitesttablets.

DOSAGE AND ADMINISTRATION
Adults: 1 to 2 g daily given in divided doses at 6-, 8-, or 12 – hourly intervals, in severe or deep-seated infections, the dose can be increased to up to 6 g daily.
Children: 25 to 100 mg / kg daily in divided doses to a maximum of 4 g daily. For the prophylaxis of recurrent urinary-tract infection, Cefalexin may be given in a dose of 125 mg at right dose of Cefalexin should be reduced in renal impairment.

CONTRAINDICATION
Patients who are known or suspected to be allergic to other cephalosporins should not be treated with Cefalexin.

ADVERSE EFFECTS & SPECIALFRECAUTIONS
Side effects include nausea, vomiting, diarrhea and abdominal discomfort. Skin rashes occur in about 1% of patients treated with Cefalexin and rises in serum transaminases have been noted. Eosinophilia and neutropenia have occurred in a few patients. Super- infection with resistant micro-organisms, particularly Candida, may follow treatment. Care is necessary in treating patients known to be hypersensitive to penicillin or with known histories of allergy. Reduced dosage is necessary in patients with impaired kidney function. The urine of patients taking Cefalexin may give a false positive reaction for glucose with copper-reduction reagents. Positive results to the Coomb’s test have been reported with Cefalexin.

CAUTION
Foods, Drugs, Devices, & Cosmetics Act prohibits dispensing without prescription.

KEEP ALL MEDICINES OUT OF REACH OF CHILDREN.

STORAGE CONDITION
Store at temperatures not exceeding 300C.

AVAILABILITY
Alu/PVC Blister of 10’s, box of 100’s.

“For suspected adverse drug reaction, report to the FDA: www.fda.gov.ph“