Clarithromycin is a prescription macrolide antibiotic that stops susceptible bacteria from growing. In the UK it is used for selected respiratory, ear, skin and soft-tissue infections, and in combination treatment to eradicate Helicobacter pylori.
Macrolide antibiotic.
Immediate-release or prolonged-release tablets, oral suspension and intravenous infusion.
Prescription-only medicine in the UK; intravenous treatment is normally given in hospital.
Licensed uses vary by product, formulation, age and route and require infection with a susceptible organism.
Adults and children aged 12 years or over: susceptible lower respiratory infections, sinusitis, pharyngitis, and mild-to-moderate skin or soft-tissue infections.
Selected immediate-release tablets: eradication of Helicobacter pylori associated with ulcer disease, only as part of a combination regimen.
Children aged 6 months to 12 years using selected oral suspensions: bacterial pharyngitis, acute otitis media, bacterial sinusitis, exacerbations of chronic bronchitis, mild-to-moderate community-acquired pneumonia, and skin or soft-tissue infections.
Intravenous clarithromycin: susceptible respiratory or skin and soft-tissue infections when parenteral treatment is required.
Clarithromycin binds to the bacterial 50S ribosomal subunit and inhibits protein production. This usually stops susceptible bacteria multiplying, allowing the immune system to clear the infection.
Regimens vary with the infection, severity, age, weight, kidney function, formulation and interacting medicines. The prescription and product instructions should be followed.
500 mg once daily with food; 1,000 mg once daily may be used for more severe infection.
Usually 6 to 14 days.
1,000 mg daily, divided into two 500 mg doses, each administered as an intravenous infusion over 60 minutes.
Intravenous therapy may be given for 2 to 5 days, changing to oral treatment when clinically appropriate.
7.5 mg/kg twice daily, up to a maximum of 500 mg twice daily.
Take clarithromycin exactly as prescribed and complete the course unless a clinician tells you to stop.
Swallow tablets with water. Immediate-release tablets can generally be taken with or without food.
Take Xetinin XL prolonged-release tablets with food and do not crush or chew them.
Shake oral suspension before measuring each dose. Use the supplied oral syringe or medicine spoon, not a kitchen teaspoon.
Food or a drink immediately after oral suspension may reduce its bitter aftertaste.
Intravenous clarithromycin must be prepared and administered by a healthcare professional.
Clarithromycin can be used during pregnancy when a doctor considers it appropriate. Available information does not show impaired fetal development, but the infection, treatment benefits and possible alternatives should be considered with the prescriber; routine extra monitoring for major birth defects is not usually required solely because of exposure.
Clarithromycin can generally be used while breastfeeding a healthy, full-term infant with precautionary monitoring. Watch for diarrhoea, vomiting, oral thrush, rash, irritability or reduced feeding and seek advice if concerns arise; specialist assessment may be needed for premature or unwell infants.
Clarithromycin inhibits CYP3A4 and transport proteins and can also prolong cardiac repolarisation. A medication review is important before treatment.
The combination is contraindicated because markedly increased statin exposure can cause myopathy or rhabdomyolysis.
Exposure may increase; the prescriber may pause treatment, reduce the dose or select an alternative.
Concurrent use is contraindicated because QT prolongation and serious ventricular arrhythmias may occur.
Clarithromycin can substantially increase colchicine exposure and toxicity; some combinations are contraindicated, particularly with kidney or liver impairment.
Anticoagulant effects or bleeding risk may increase, requiring clinical review and, for warfarin, closer coagulation monitoring.
Digoxin exposure may rise, increasing toxicity risk; clinical assessment and concentration monitoring may be required.
Concentrations or adverse effects may increase, so monitoring and dose adjustment may be necessary.
Concurrent use is contraindicated because severe ergot toxicity and ischaemia can occur.
It may reduce clarithromycin exposure and should not be started without checking with a pharmacist or prescriber.
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No. Clarithromycin is a macrolide antibiotic and may sometimes be selected when a penicillin-type antibiotic is unsuitable, depending on the infection.
No. It acts against susceptible bacteria and does not treat viral infections such as colds or influenza.
Symptoms often begin improving within a few days. Seek medical advice if they worsen or do not start improving as expected.
Immediate-release tablets can generally be taken with or without food. Xetinin XL prolonged-release tablets must be taken with food.
No. They must be swallowed whole so that the prolonged-release mechanism works correctly.
Altered taste is a recognised adverse effect. Taking food or a drink immediately after oral suspension may help with its bitter aftertaste.
There is no specific prohibition, but alcohol may worsen dizziness, nausea or stomach upset. Avoid driving if clarithromycin makes you dizzy.
Not directly. However, vomiting or severe or prolonged diarrhoea can reduce oral contraceptive protection, so follow the contraceptive packet instructions.
Clarithromycin can markedly alter the concentrations of several medicines and can combine with some drugs to increase heart-rhythm, bleeding or muscle-toxicity risks.
Yes, when prescribed appropriately. Selected oral suspensions are licensed for children aged 6 months to 12 years, with doses based on body weight; tablet suitability depends on age and formulation.
Yes. Reduced kidney function can increase exposure and require dose adjustment. Prolonged-release tablets may be unsuitable when the necessary reduced dose cannot be provided.
Maintain fluids for mild diarrhoea, but seek prompt medical advice for severe, persistent, bloody or mucus-containing diarrhoea. Do not self-treat severe diarrhoea without professional advice.
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.