Monuril (Fosfomycin Trometamol)

Monuril (fosfomycin trometamol) is indicated for bacterial infections of the urinary tract, specifically uncomplicated lower urinary tract infections.

• Uncomplicated urinary tract infection: provides a single‑dose oral therapy that eradicates common uropathogens.
• Acute uncomplicated cystitis: resolves symptoms and clears bacterial growth in adult women.
• Single‑dose treatment of E. coli urinary infection: achieves microbiological cure with one administration.

• Fosfomycin trometamol is a phosphonic acid derivative that penetrates bacterial cells through glycerophosphate transporters. Inside the cell it inactivates the enzyme MurA (UDP‑N‑acetylglucosamine enolpyruvyl transferase), blocking the first step of peptidoglycan synthesis. By preventing formation of N‑acetylmuramic acid, the drug halts bacterial cell‑wall construction, leading to bactericidal activity against a broad range of Gram‑negative and some Gram‑positive organisms.

Fosfomycin trometamol may cause adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Nausea: mild stomach upset often reported.
• Diarrhea: loose stools occurring during treatment.
• Headache: transient cranial discomfort.
• Abdominal pain: cramping or discomfort in the abdomen.
• Dyspepsia: indigestion or feeling of fullness.

Serious or Rare Side Effects

• Allergic reaction: rash, itching, swelling that may indicate hypersensitivity.
• Severe skin eruption: Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Clostridioides difficile infection: colitis associated with antibiotic use.
• Hepatic dysfunction: elevated liver enzymes or jaundice.
• Anaphylaxis: life‑threatening systemic allergic response.
• Renal impairment: acute kidney injury in susceptible patients.

Before prescribing Monuril, consider the following precautions to ensure safe use.

• Renal function: assess creatinine clearance, dose may need adjustment in severe impairment.
• Pregnancy: use only if clearly needed after risk‑benefit evaluation.
• Breastfeeding: evaluate infant exposure; consider alternative therapy.
• Known hypersensitivity: avoid in patients with previous fosfomycin allergy.
• Concomitant nephrotoxic drugs: monitor renal parameters closely.
• Store at below 25°C: keep in the original packaging, protect from moisture and heat.

Fosfomycin trometamol can interact with other medicines; awareness of major and moderate interactions helps prevent adverse outcomes.

Major Interactions (Avoid)

• Antacids containing aluminum or magnesium: may markedly reduce fosfomycin absorption.
• Probenecid: can increase fosfomycin plasma concentrations, raising toxicity risk.
• Warfarin: may potentiate anticoagulant effect, requiring INR monitoring.

Moderate Interactions (Monitor Closely)

• Oral contraceptives: fosfomycin may reduce hormonal efficacy, advise backup contraception.
• Diuretics: monitor electrolytes and renal function during combined use.
• Ciprofloxacin or other fluoroquinolones: additive nephrotoxic potential, observe kidney function.