Meds and you

Updated 11 February 2013


Clarithromycin is a broad spectrum antibiotic, effective in the treatment of upper and lower respiratory tract infections.


Clarithromycin is the active ingredient of Clacee, ClariHexal, Klacid, Klarithran, Klarizon and Merck-Clarithromycin.

General Information

Clarithromycin is a broad spectrum antibiotic, effective in the treatment of upper and lower respiratory tract infections, uncomplicated skin and soft tissue infections and middle-ear infections, caused by susceptible organisms.

Clarithromycin is often prescribed to eradicate Helicobacter pylori, a bacterium thought to be responsible for stomach ulcers. It is used in combination with a proton pump-inhibiting drug - a drug that reduces stomach acid secretion - and another antibiotic to decrease recurrence.

It is important to note that this medication is only effective against bacterial infections. If your infection is the result of a viral or fungal infection, it will be ineffective.

Antibiotic resistance - when bacteria develop the ability to defend themselves against the effect of an antibiotic - occurs frequently with many antibiotics. This mostly happens when patients do not complete the prescribed course in full, allowing bacteria to recover from treatment, and by using antibiotics for non-bacterial infections such as cold and flu.

How does clarithromycin work?

Clarithromycin functions by inhibiting bacterial protein synthesis. It thus prevents bacteria from producing specific proteins essential for their survival.

Fast facts

Drug schedule: Schedule 4

Available as: Clarithromycin is available in tablets, modified release tablets, suspension and injection.

What does it do? Clarithromycin is an antibiotic.

Overdose risk: Low

Dependence risk: Low

Is clarithromycin available as a generic? Yes

Is clarithromycin available on prescription only? Yes

User information

Dietary advice: Clarithromycin can be taken with or without food. Ingest plenty of fluid when taking clarithromycin. For optimal results the antibiotic should be taken 1 hour before or 2 hours after a meal.

Stopping this medicine: Do not stop using clarithromycin before you have completed the course prescribed by your doctor, even if you begin to feel better.

Prolonged use: Clarithromycin is generally only used for short periods of time. Prolonged use may be associated with antibiotic resistance.

Special precautions

Consult your doctor before using this drug if:

  • you are allergic to other antibiotics, including erythromycin and clarithromycin
  • You have a liver or kidney disease
  • You are taking cholesterol lowering medication
  • If you have a heart condition.

Pregnancy: Avoid. Potential risk to the foetus has been reported. Consult your doctor before use, or if you are planning to fall pregnant.

Breastfeeding: Avoid. It is unknown how this medication may affect your baby. Consult your doctor before use.

Porphyria: Avoid. It is unknown how this medication may affect your condition. Consult your doctor before use.

Infants and children: This medication is safe for use in children at the recommended dose.

Elderly: No special precautions need to be taken.

Driving and hazardous work: No special precautions need to be taken.

Alcohol: Avoid concomitant use of alcohol with this medication.

Possible side effects

Side effect


Consult your doctor



Only if severe

In all cases

Stomach pain / diarrhoea



Nausea / vomiting






Dizziness / confusion / hallucinations



Swelling of lips / face and neck



Altered sense of taste / smell



Difficulty breathing



Hives, itch, rash



Joint / muscle pain



Yellowish discolouration of skin or eyes




Drug interactions

Statin cholesterol lowering drugs

Possibility of muscle pain and spasms

Zidovudine, ritonavir

Clarithromycin reduces effect of some anti-viral drugs


Increased risk of warfarin toxicity


Increased risk of carbamazepine toxicity


Increased risk of cardiac toxicity


Increased risk of digoxin toxicity

Oral contraceptives

Decreased efficacy of the pill


Increased risk of theophylline toxicity

Disease interactions

Consult your doctor before using this drug if you have a liver or kidney disease or if you have a heart condition.

Overdose action

A small overdose is no cause for concern. In case of intentional large overdose seek emergency medical attention.

Recommended dosage

Adults: 250 -1000 mg/day in 1-2 doses

Children: 7.5-15 mg/kg/dose (maximum 500 mg) 12 hourly


Read Health24’s Comments Policy

Comment on this story
Comments have been closed for this article.