Zitromax (Azithromycin) 500 mg: Uses, Safety and Interactions

Azithromycin and brand names

The Zitromax 500 mg record contains azithromycin, a macrolide antibiotic. This summary uses current UK azithromycin tablet and US Zithromax information. Brand spelling, authorised uses and available packs differ between countries; these sources do not establish that every brand or pack is interchangeable. Oral tablets also have different instructions from suspensions or intravenous formulations.

Which infections can it treat?

The UK tablet label includes selected bacterial respiratory, ear, skin and chlamydial infections, subject to its age, weight and clinical restrictions. A clinician must consider local resistance and current treatment guidance. Azithromycin is not an answer to every sore throat, cough or sexually transmitted infection, and it does not treat viral colds. In particular, an old treatment schedule found online should not be used to self-treat suspected gonorrhoea, where resistance and appropriate testing matter.

Common effects and urgent warnings

Diarrhoea, nausea, abdominal pain and vomiting are common problems. Severe or persistent diarrhoea may reflect antibiotic-associated colitis and needs assessment. Rare serious reactions include liver injury and severe allergy or skin reactions. Yellow eyes, dark urine, facial swelling, breathing difficulty, or a widespread blistering rash warrant urgent medical help. Azithromycin can prolong the QT interval and cause a dangerous heart rhythm in susceptible people. Fainting, marked palpitations or new chest symptoms should not be ignored. Risk assessment matters with known QT prolongation, slow heart rate, low potassium or magnesium, or significant heart disease.

Medicine review and individual circumstances

Other QT-prolonging medicines can add risk. Warfarin may require additional clotting tests; digoxin and colchicine merit careful review because azithromycin can affect P-glycoprotein transport. The UK label advises against combining it with ergot derivatives. Nelfinavir can increase azithromycin exposure. Azithromycin is not pharmacologically identical to clarithromycin, so another macrolide's interaction list should not simply be copied. Tell the prescriber about liver disease, myasthenia gravis, pregnancy and breastfeeding. Treatment choice and duration depend on the diagnosed infection; this overview does not provide a personal antibiotic course.

Sources

• Azithromycin 500 mg tablets — UK SmPC, Sandoz — Text revision 27 February 2026; emc update 30 April 2026
• ZITHROMAX oral tablets — US prescribing information, Pfizer — US prescribing information revised July 2026

Source check: 30 October 2026. This date records verification of the cited sources, not a clinical review by a doctor or pharmacist. Use the current leaflet for your product and seek professional advice for personal treatment decisions.