Safexin 500mg capsules

Indications

• Bacterial infections due to sensitive Gram-positive and Gram-negative bacteria
• Skin infections
• Soft-tissue infections
• Uncomplicated urinary-tract infections
• Acute diverticulitis (in combination with metronidazole)
• Prophylaxis of recurrent urinary-tract infections

Dosage

Children: Child 1 month–11 years: 25 mg/kg 2–4 times a day (max. per dose 500 mg). Child

Adults: 250 mg every 6 hours, alternatively 500 mg every 8–12 hours; increased to 1–1.5 g every 6–8 hours for severe infections.

Mechanism of action

Cefalexin inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins located in the bacterial cytoplasmic membrane. This action prevents the cross-linkage of peptidoglycan chains, which is essential for bacterial cell wall strength and rigidity. Consequently, this leads to cell lysis and death, particularly in rapidly dividing bacteria.

Pharmacodynamics

Cefalexin is bactericidal and exhibits activity primarily against Gram-positive bacteria. It is effective in treating superficial infections resulting from minor wounds or lacerations. By interfering with the cross-linking reaction between N-acetyl muramic acid and N-acetylglucosamine in the bacterial cell wall, cefalexin promotes cell lysis, making it a widely used antibiotic in clinical practice.

Pharmacokinetics

Cefalexin is well absorbed when taken orally, with peak plasma concentrations typically occurring within 1 hour of administration. It is widely distributed throughout body tissues and fluids, including bile, urine, and synovial fluid. The drug is primarily excreted unchanged in the urine, and its half-life is approximately 1 hour. Renal impairment may necessitate dosage adjustments.

Contra-indications

• Hypersensitivity to cephalosporins
• History of immediate hypersensitivity to penicillin and other beta-lactams

Adverse effects

• Abdominal pain
• Diarrhoea
• Dizziness
• Eosinophilia
• Headache
• Leucopenia
• Nausea
• Neutropenia
• Pseudomembranous enterocolitis
• Skin reactions
• Thrombocytopenia
• Vomiting
• Vulvovaginal candidiasis
• Anaphylactic reaction
• Angioedema
• Agranulocytosis
• Hemolytic anemia
• Tubulointerstitial nephritis
• Severe cutaneous adverse reactions (SCARs)

Interactions

• Probenecid may increase the serum concentration of cephalexin
• Antacids may decrease the absorption of cephalexin
• Other nephrotoxic drugs may increase the risk of kidney damage

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of superinfection during prolonged therapy
• Caution in patients with a history of gastrointestinal disease, particularly colitis

Pregnancy

Not known to be harmful.

Breast-feeding

Present in milk in low concentration, but generally considered appropriate to use.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Capsules: 250 mg, 500 mg
• Oral suspension: 125 mg/5 mL, 250 mg/5 mL

Mechanism of action

Cephalexin is a first generation cephalosporin antibiotic. Cephalosporins contain a beta lactam and dihydrothiazide. Unlike penicillins, cephalosprins are more resistant to the action of beta lactamase. Cephalexin inhibits bacterial cell wall synthesis, leading breakdown and eventualy cell death. CEPHALOTHIN & ITS CONGENERS INHIBIT BACTERIAL CELL-WALL SYNTHESIS IN MANNER SIMILAR TO THAT OF PENICILLIN. /CEPHALOSPORINS/ The penicillins and their metabolites are potent immunogens because of their ability to combine with proteins and act as haptens for acute antibody-mediated reactions. The most frequent (about 95 percent) or "major" determinant of penicillin allergy is the penicilloyl determinant produced by opening the beta-lactam ring of the penicillin. This allows linkage of the penicillin to protein at the amide group. "Minor" determinants (less frequent) are the other metabolites formed, including native penicillin and penicilloic acids. /Penicillins/ Bactericidal; action depends on ability to reach and bind penicillin-binding proteins located in bacterial cytoplasmic membranes; cephalosporins inhibit bacterial septum and cell wall synthesis, probably by acylation of membrane-bound transpeptidase enzymes. This prevents cross-linkage of peptidoglycan chains, which is necessary for bacterial cell wall strength and rigidity. Also, cell division and growth are inhibited, and lysis and elongation of susceptible bacteria frequently occur. Rapidly dividing bacteria are those most susceptible to the action of cephalosporins. /Cephalosporins/ CEPHALOSPORIN C IS VERY RESISTANT TO ACTION OF PENICILLINASE, FOR WHICH IT IS BOTH COMPETITIVE & NONCOMPETITIVE INHIBITOR, DEPENDING ON SUBSTRATE TESTED... /CEPHALOSPORINS/

Pharmacodynamics

Cephalexin (also called Cefalexin) is a first generation cephalosporin antibiotic. It is one of the most widely prescribed antibiotics, often used for the treatment of superficial infections that result as complications of minor wounds or lacerations. It is effective against most gram-positive bacteria through its inihibition of the cross linking reaction between N-acetyl muramicacid and N-acetylglucosamine in the cell wall, leading to cell lysis.