Medolexin (Cefalexin)

Cefalexin is employed to manage infections caused by susceptible bacteria across several organ systems.

• Skin and soft tissue infections: effective in treating mild to moderate cellulitis, impetigo and wound infections.
• Respiratory tract infections: used for acute bronchitis, sinusitis and community‑acquired pneumonia caused by susceptible strains.
• Urinary tract infections: clears uncomplicated cystitis and pyelonephritis when bacteria are sensitive.
• Bone and joint infections: aids in managing osteomyelitis and septic arthritis caused by susceptible organisms.

• Cefalexin inhibits bacterial cell wall synthesis by binding to penicillin‑binding proteins (PBPs) located on the inner surface of the bacterial membrane. This binding blocks the cross‑linking of peptidoglycan strands, weakening the cell wall and leading to osmotic lysis of susceptible Gram‑positive and some Gram‑negative organisms.

Cefalexin may cause a range of adverse reactions, most of which are mild and reversible.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Diarrhea: loose stools, often self‑limiting.
• Rash: mild skin erythema or itching.
• Headache: transient tension‑type headache.

Serious or Rare Side Effects

• Clostridioides difficile‑associated colitis: severe diarrhea requiring medical attention.
• Anaphylaxis: rapid onset of breathing difficulty, swelling and hypotension.
• Stevens‑Johnson syndrome: severe skin blistering and mucosal involvement.

Before prescribing or dispensing cefalexin, consider the following safety measures.

• Assess renal function: adjust dose in patients with impaired renal clearance.
• Monitor for allergic reactions: discontinue immediately if severe rash or anaphylaxis occurs.
• Use with caution in pregnancy: category B, benefits generally outweigh potential risks.
• Avoid use in patients with known hypersensitivity to cephalosporins or penicillins.
• Store at ambient temperature: keep in the original pack, protect from moisture and heat.

Cefalexin can interact with several medicines, altering efficacy or safety.

Major Interactions (Avoid)

• Probenecid: may increase cefalexin plasma concentrations, raising toxicity risk.
• Warfarin: can enhance anticoagulant effect; monitor INR closely.
• Oral contraceptives: may reduce hormonal efficacy, consider alternative contraception.

Moderate Interactions (Monitor Closely)

• Aminoglycosides: concurrent nephrotoxicity risk; observe renal function.
• Loop diuretics: may increase renal clearance of cefalexin; dose adjustment may be needed.