Meropenem Milpharm (Meropenem Trihydrate)

Meropenem is a broad‑spectrum carbapenem antibiotic indicated for serious infections caused by susceptible bacteria.

• Complicated intra‑abdominal infections: provides bactericidal activity against mixed flora, aiding resolution of severe abdominal sepsis.
• Complicated urinary tract infections: eliminates resistant Gram‑negative pathogens, facilitating cure of pyelonephritis and catheter‑associated infections.
• Nosocomial pneumonia: treats hospital‑acquired and ventilator‑associated pneumonia caused by multidrug‑resistant organisms.
• Septicemia: rapidly clears bloodstream infections by targeting a wide range of Gram‑positive and Gram‑negative bacteria.
• Meningitis: penetrates the cerebrospinal fluid to eradicate bacterial meningitis pathogens when susceptibility is confirmed.

• Meropenem binds with high affinity to penicillin‑binding proteins (PBPs) on bacterial cell walls, inhibiting the final transpeptidation step of peptidoglycan synthesis. This disruption weakens the cell wall, leading to osmotic instability and bacterial cell death. Its broad spectrum includes many Gram‑negative, Gram‑positive, and anaerobic organisms, and it is resistant to most β‑lactamases. The drug’s stability against most β‑lactamases allows it to retain activity against organisms that produce extended‑spectrum β‑lactamases (ESBL) and carbapenemases, though susceptibility testing remains essential.

Meropenem may be associated with a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Nausea: mild gastrointestinal upset occurring in many patients.
• Diarrhea: loose stools, occasionally leading to dehydration.
• Rash: skin erythema or pruritus without systemic involvement.
• Headache: transient cephalic discomfort.
• Elevated liver enzymes: mild, reversible increases in transaminases.
• Injection site pain: discomfort at the intravenous infusion site.

Serious or Rare Side Effects

• Seizures: especially in patients with renal impairment or CNS disorders.
• Anaphylaxis: acute, potentially life‑threatening hypersensitivity reaction.
• Clostridioides difficile‑associated diarrhea: severe colitis due to gut flora disruption.
• Stevens‑Johnson syndrome/toxic epidermal necrolysis: severe skin and mucous membrane reactions.
• Renal toxicity: acute kidney injury in susceptible individuals.
• Hemolytic anemia: rare immune‑mediated destruction of red blood cells.

Prior to initiating Meropenem therapy, clinicians should evaluate patient-specific factors and monitor for potential complications.

• Renal function: assess creatinine clearance and adjust dose in renal impairment.
• Hypersensitivity: avoid use in patients with known allergy to β‑lactam antibiotics.
• Seizure risk: use caution in patients with a history of epilepsy or CNS disorders.
• Concomitant valproic acid: monitor for decreased serum levels and possible seizure breakthrough.
• Superinfection: watch for overgrowth of non‑susceptible organisms, including fungi.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Meropenem can interact with other medicines, influencing efficacy or safety.

Major Interactions (Avoid)

• Valproic acid: meropenem reduces plasma concentrations, risking loss of seizure control.
• Probenecid: may increase meropenem plasma levels, heightening toxicity risk.
• Carbapenem‑resistant organisms: co‑administration with other carbapenems offers no benefit and may promote resistance.

Moderate Interactions (Monitor Closely)

• Aminoglycosides: combined nephrotoxic potential requires renal function monitoring.
• Loop diuretics: may enhance renal clearance, affecting meropenem exposure.
• Warfarin: monitor INR as antibiotic therapy can alter anticoagulant effect.
• Oral contraceptives: possible reduction in efficacy; advise alternative contraception.