Mechanism of action of cephalexin is similar to penicillin. It acts by inhibiting bacterial cell wall synthesis, lack of bacterial cell wall results in death due to lysis of bacteria. Food does not interfere with absorption of cephalexin. Duration of action is prolonged in patients with impaired renal function.
Probenecid delays urinary excretion of cephalexin and prolong its action. Cephalexin is not active against most strains of Enterobacter species, Morganella morganii, Proteus vulgaris, Pseudomonas species, Acinetobacter calcoaceticus and MRSA. Cephalexin is used in treatment of respiratory tract infection, otitis media, skin infections, bone infection and genitourinary infection caused by sensitive organisms. Cephalexin is normally effective in the eradication of streptococci from the nasopharynx.
For the prophylaxis of recurrent urinary-tract infection, doxycycline and cephalexin, cephalexin may be given in a dose of mg doxycycline and cephalexin night. Cephalexin dose reduction is needed in patients with renal impairment. Cephalexin is contraindicated in patients with known allergy to the cephalosporin group of antibiotics.
Cephalexin is avoided in porphyria. Prolonged administration of cephalexin may lead to doxycycline and cephalexin of nonsusceptible microorganisms. Like other cephalosporins cephalexin consists of a dihydrothiazine ring fused to a beta-lactam ringand has a D-phenylglycyl group doxycycline and cephalexin a substitute at the 7-amino position and an unsubstituted methyl group at the 3-position.
The doxycycline and cephalexin structure is:. Like other cephalosporins, cephalexin possesses a mechanism of action similar to penicillins i. Thus cephalexin is also a bactericidal drug.
Also cephalexin is not active against most strains of Enterobacter species, Morganella morganii, doxycycline and cephalexin, Proteus vulgaris, Pseudomonas species and Acinetobacter calcoaceticus. This can lead to the binding of the cephalosporin to Beta —lactamases which hydrolyses the Beta-lactam ring and inactivates the cephalosporin, doxycycline and cephalexin.
The most predominant mechanism of resistance to cephalexin like other cephalosporins is destruction of the cephalosporins by hydrolysis of the Beta-lactam ring. Enormous amounts of Beta-lactamase are released into the surrounding medium by many gram positive organisms. Though the secretion of Beta-lactamase by gram-negative bacteria is less, doxycycline and cephalexin, the position of their enzyme in the periplasmic space make it more effective in destroying cephalosporins because they diffuse to their targets on the inner membrane, as is the case for the penicillins.
Cephalexin is rapidly and completely absorbed orally. It can be administered without food or with betel and oral cancer. It achieves peak plasma concentration 1 hour after oral administration. The plasma half-life is about 1 hour; it increases with reduced renal function. Cephalexin is extensively distributed in the body but does not enter the CSF in substantial quantities. It crosses the placenta and small quantities are found in breast milk.
Cephalexin is not metabolised. The major route of elimination is renal. Cephalexin is eliminated unchanged in urine by glomerular filtration and tubular secretion.
Probenecid delays urinary excretion. Therapeutically effective concentrations may be found in the bile and some may be excreted by this route. Cephalexin is removed by haemodialysis and peritoneal dialysis. No data is available to validate the effectiveness of cefuroxime in the treatment of penicillin-resistant strains of Streptococcus pyogenes. Cephalexin is typically given as the monohydrate although the hydrochloride is sometimes used. Doses are expressed in terms of the equivalent amount of anhydrous Cephalexin; 1.
Doses of cephalexin may need to be reduced in patients with renal impairment, doxycycline and cephalexin. The following maximum daily doses are recommended according to doxycycline and cephalexin clearance CC:. It is a pregnancy category B drug, doxycycline and cephalexin. Animal studies have not shown any harmful effects to foetus.
But well doxycycline and cephalexin clinical trials have not been conducted in humans. Cephalexin is excreted in human milk; care should be taken while prescribing it to nursing mothers. No general differences in safety or effectiveness were seen between elderly subjects and younger adult subjects. Antibiotic Drugs Doxycycline and cephalexin Cephalexin is an orally active first generation bactericidal cephalosporin.