Maxigan (Clarithromycin)

Clarithromycin is used to treat infections caused by susceptible bacteria across several organ systems.

• Community‑acquired pneumonia: eradicates typical bacterial pathogens and improves respiratory function.
• Acute bacterial sinusitis: relieves sinus inflammation and clears infection.
• Skin and soft tissue infections: eliminates susceptible Gram‑positive organisms.
• Helicobacter pylori eradication: forms part of combination therapy to eradicate the bacterium.
• Other susceptible bacterial infections: provides coverage for a range of Gram‑positive and some Gram‑negative organisms.

• Clarithromycin binds to the 50S subunit of bacterial ribosomes, blocking the translocation step of protein synthesis. This inhibition prevents peptide chain elongation, halting bacterial growth and leading to a bacteriostatic effect against susceptible organisms.

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

Common Side Effects

• Nausea: mild to moderate upset stomach.
• Diarrhea: loose stools, often self‑limiting.
• Abdominal pain: cramping or discomfort.
• Taste disturbance: altered or metallic taste.
• Headache: mild to moderate intensity.
• Vomiting: occasional episodes.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• QT prolongation: potential cardiac arrhythmia risk.
• Hepatic dysfunction: elevated liver enzymes or hepatitis.
• Clostridioides difficile‑associated diarrhea: severe colitis.
• Stevens‑Johnson syndrome: rare severe skin reaction.
• Neutropenia: marked reduction in white blood cells.

Before initiating Clarithromycin therapy, consider the following safety measures.

• Assess renal function: adjust use in severe renal impairment.
• Review hepatic status: use cautiously in patients with liver disease.
• Monitor cardiac rhythm: avoid in individuals with known QT prolongation.
• Avoid use with macrolide‑resistant organisms: ensure susceptibility testing.
• Counsel on gastrointestinal upset: advise taking with food if tolerated.
• Store at ambient temperature: keep in the original pack, protect from moisture and light.

Clarithromycin interacts with several medicines; awareness helps prevent adverse outcomes.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., itraconazole, ketoconazole): may increase clarithromycin levels and toxicity.
• QT‑prolonging drugs (e.g., quinidine, sotalol): combined use raises risk of arrhythmia.
• Statins metabolized by CYP3A4 (e.g., simvastatin): heightened risk of myopathy.

Moderate Interactions (Monitor Closely)

• Warfarin: clarithromycin can enhance anticoagulant effect; monitor INR.
• Antacids containing aluminum or magnesium: may reduce absorption; separate dosing by at least 2 hours.
• Oral contraceptives: possible reduction in efficacy; advise backup contraception.