Macrolides (Azithromycin, Clarithromycin, Erythromycin)

Medication Information Leaflet

What is this medication for?

Macrolides are a class of antibiotics used to treat or prevent bacterial infections. It is commonly used for respiratory tract, skin and soft tissue, H. pylori and sexually transmitted infections.

How should I take/use this medication?

  • You should complete each course of antibiotics even if you feel better. Incomplete treatment might cause the infection to return or lead to antibiotic resistance. When antibiotic resistance happens, the antibiotic will not be effective anymore.

  • For Azithromycin, Clarithromycin and Erythromycin Suspension (Erythromycin Ethyl succinate): Take with or without food.

  • For Erythromycin Tablets (Erythromycin Stearate): Take on an empty stomach, half to one hour before food.

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What precautions should I take?

Inform your healthcare professional if:

  • You are allergic to this medication or any of the other ingredients of this medication

  • You have myasthenia gravis (a disease that causes muscle weakness)

  • You ever had heart issues e.g. abnormal heartbeats or prolonged QT on ECG

  • You are taking medications to treat abnormal heartbeats

  • You are pregnant, planning to become pregnant, or breastfeeding

  • You are taking any other medications, including supplements, traditional medications and herbal remedies

What are some common side-effects of this medication?

  • Nausea/vomiting, stomach discomfort, diarrhoea

    • Take the medication with or after food.

    • If diarrhoea occurs, drink plenty of water to prevent dehydration.

    • If you experience persistent diarrhoea, stomach pain or bloody stools, do seek medical advice immediately.

What are some rare but serious side-effects that require immediate medical attention?

Allergic Reaction

  • Symptoms of a drug allergy include one or more of the following: swollen face/eyes/lips/tongue, difficulty breathing and skin rashes over your whole body.

  • If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

Liver Injury

  • Very rarely, this medication may affect the liver. Signs of liver injury include yellowing of the eye whites or skin, darkened urine, light coloured stools, stomach pain, loss of appetite and feeling tired.

Experience abnormal or fast heartbeats

What food or medication should I avoid when I take this medication?

Macrolides may affect the levels of other medications in your body. Inform your healthcare providers if you are on long term medications for additional advice.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

Erythromycin and Clarithromycin Suspension: Follow the storage and expiry date as stated on the bottle or as advised by your healthcare professionals.

How should I throw away this medication safely?

Please return any unused or expired antibiotics to the pharmacy where you received it from.


If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Jul 2021

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