Clarithromycin

Clarithromycin has an antimicrobial spectrum similar to that of erythromycin.Clarithromycin is more acid-stable than erythromycin and is rapidly absorbed in the body. Its oral bioavailability is ~50% due to first-pass metabolism.

Indication.

• Upper and lower respiratory tract infections, sinusitis, otitis media, whooping cough, atypical pneumonia, skin and skin structure infections due to Strep. pyogenes and Staph. Aureus.
• They are used as a component of a triple-drug regimen to eradicate H. pylori in 2 weeks.
• As a first-line drug in combination regimens for MAC infection in AIDS patients and a second-line drug for other atypical mycobacterial diseases and leprosy.

Adverse effects

• GI disturbance.
• Diarrhoea is occasional.
• Reversible hearing impairment.
• Pseudomembranous enterocolitis, hepatic dysfunction or rhabdomyolysis.
• Hypersensitivity; rashes and fever.
• Hepatitis with cholestatic jaundice resembling viral hepatitis and extrahepatic biliary obstruction occurs.
• Taste disturbances.

Drug interactions.

• Sensitivity to other macrolide antibiotics.

Contraindications.

• Impaired liver functions.
• Jaundice and syphilis in pregnancy.

Dosage.

• 250 mg BD for 7 days; severe cases 500 mg BD up to 14 days.
• CLARIBID 250, 500 mg tablets, 250 mg/5 ml dry syrup;
• CLARIMAC 250, 500 mg tablets; SYNCLAR 250 mg tablets, 125 mg/5 ml dry syrup.