Clarithromycin

Lower respiratory tract infections, sinusitis, skin infections, H. pylori eradication (with PPI and amoxicillin/metronidazole), and mycobacterial infections.

Clarithromycin inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. It has excellent tissue penetration and intracellular accumulation, making it effective against atypical organisms like Mycoplasma, Chlamydophila and Legionella.

Adults and children. Important drug interactions - inhibits CYP3A4 and can increase levels of statins, colchicine, warfarin and many others. Caution in liver and kidney impairment. Avoid with certain cardiac medications.

Order online and we review your request. A prescriber checks your consultation form for clinical appropriateness and contacts you if anything else is needed. Once approved, your medication is dispensed and delivered to your door.

Tracked: Tracked delivery, arrives in two working days - Free

When it arrives: Every order is sent tracked. Where this page says in post today, it goes out today. Where it says in post tomorrow, it goes out the next working day. On the rare occasions a medicine is unavailable, we will contact you to talk about timing and alternatives.

We dispense clinically equivalent generic medications where available. Prices shown are for the generic version. If you prefer the branded version, let us know in your order form and we will confirm any price difference.

Clarithromycin from £20.99 per course.

Common: diarrhoea, nausea, rash, abdominal discomfort. Amoxicillin/co-amoxiclav: common rash (especially with viral infections). Metronidazole: metallic taste, nausea. Doxycycline: photosensitivity, oesophageal irritation. Rare but serious: Clostridium difficile colitis (persistent diarrhoea), anaphylaxis (penicillins), tendon damage (ciprofloxacin).

Penicillin allergy: do not take amoxicillin, co-amoxiclav, or flucloxacillin. Ciprofloxacin: avoid in tendon disorders, epilepsy, myasthenia gravis. Metronidazole: avoid alcohol during treatment and for 48 hours after. Doxycycline: avoid in children under 12 (teeth staining).

Metronidazole: severe reaction with alcohol (disulfiram-like). Warfarin: many antibiotics alter INR - more frequent monitoring needed. Ciprofloxacin: avoid dairy, calcium, iron, and antacids within 2 hours. Oral contraceptives: no evidence that most antibiotics reduce efficacy (except rifampicin).

Penicillins (amoxicillin, flucloxacillin): generally considered safe in pregnancy and breastfeeding. Metronidazole: avoid in 1st trimester if possible. Doxycycline/lymecycline: contraindicated in pregnancy (teeth/bone effects). Ciprofloxacin: avoid (joint cartilage risk). Nitrofurantoin: avoid at term (neonatal haemolysis). Trimethoprim: avoid in 1st trimester (folate antagonist).

Take twice daily for 7-14 days (or as directed). Can be taken with or without food. Common side effects: nausea, taste disturbance (metallic taste), diarrhoea. Important: check all your other medications for interactions. QT prolongation risk - avoid with other QT-prolonging drugs. Can worsen myasthenia gravis.