Klerimed (Clarithromycin)

Clarithromycin is a macrolide antibiotic indicated for several bacterial infections affecting the respiratory and gastrointestinal tracts as well as skin structures.

• Community‑acquired pneumonia: effective treatment of susceptible bacterial pneumonia in adults.
• Acute bacterial sinusitis: resolves infection of the sinus cavities caused by susceptible organisms.
• Acute bacterial exacerbations of chronic bronchitis: reduces bacterial load during flare‑ups.
• Skin and soft‑tissue infections: treats cellulitis, erysipelas and other infections caused by susceptible bacteria.
• Helicobacter pylori eradication (in combination therapy): part of triple or quadruple regimens to eliminate H. pylori infection.

• 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 Gram‑positive and some Gram‑negative organisms.

Clarithromycin may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Diarrhea: loose stools often occurring early in therapy.
• Abdominal pain: cramping or discomfort in the stomach area.
• Taste disturbance: altered or metallic taste perception.
• Headache: mild to moderate tension‑type headache.
• Vomiting: occasional episodes of emesis.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• QT prolongation: cardiac rhythm disturbance that may lead to arrhythmia.
• Hepatic dysfunction: elevated liver enzymes or hepatitis.
• Clostridioides difficile infection: severe colitis associated with antibiotic use.
• Stevens‑Johnson syndrome: rare but life‑threatening skin reaction.
• Severe neutropenia: marked reduction in white blood cells.

Before prescribing clarithromycin, clinicians should evaluate patient‑specific factors and monitor for potential complications.

• Renal impairment: assess kidney function and consider dose adjustment.
• Hepatic impairment: use with caution in patients with liver disease.
• Cardiac risk: avoid in patients with known QT prolongation or arrhythmias.
• Drug interactions: review concomitant medications for potential interactions.
• Pregnancy and lactation: safety not established; weigh benefits against risks.
• Store at ambient temperature below 25°C: keep in the original pack, protect from moisture.

Clarithromycin interacts with several medicines; some require avoidance while others need close monitoring.

Major Interactions (Avoid)

• Erythromycin: combined use increases risk of cardiac arrhythmias.
• Cisapride: may cause severe QT prolongation.
• Theophylline: clarithromycin can raise serum theophylline levels, leading to toxicity.

Moderate Interactions (Monitor Closely)

• Warfarin: may enhance anticoagulant effect, requiring INR monitoring.
• Simvastatin: increased risk of myopathy; consider dose reduction.
• Carbamazepine: may reduce clarithromycin concentrations, decreasing efficacy.