What are the side effects of erythromycin?

It is important to tell your health professional about any medicines you may be taking, or if you have any current illness, allergies or long-term health conditions. This will help them decide if erythromycin is suitable for you.

Side effects of erythromycin

(1 to 10 in 100 people)
(fewer than 1 in 100 people)
(fewer than 1 in 1000 people at high doses)
Stomach pain and cramps
Thrush (candida infection)
Severe allergic reactions
Infection with other bacteria (Clostridium difficile-associated disease)
Ear problems (dizziness, hearing loss, ringing in the ears [tinnitus])
Liver abnormalities (cholestatic hepatitis)
Inflammation of the pancreas (pancreatitis)
Slowed heart rate
Note: this is not a complete list of all the possible side effects of erythromycin.

Heart problems

Erythromycin can affect your heart rate, so you must tell your doctor if you have any heart problems (e.g. irregular heart beat or arrhythmia).

Intestinal blockage in babies

Erythromycin can occasionally cause a blockage in the opening from the stomach to the small intestine in very young babies (pyloric stenosis). Seek medical advice if your baby starts vomiting or is irritable while feeding.

Antibiotics and allergic reactions

Some people experience an allergic reaction to erythromycin or other antibiotics. This is due to an over-reaction of their immune system to the antibiotic.

Symptoms of an allergic reaction can include:

  • hives (large, red raised areas on the skin)
  • swollen lips, tongue or mouth
  • fever (a temperature of 38.5°C or higher)
  • breathing problems
  • fainting.

Seek medical advice if you experience any of these symptoms while you are taking an antibiotic.

It is not known why this happens to some people and not others, but it may mean that you will have to avoid taking the antibiotic in the future. There are other types of antibiotics which don’t cause this reaction that will be suitable for you.

Read more about the common side effects of antibiotics.

Who can I ask about side effects?

If you’re concerned that you or someone in your care may have had side effects related to a medicine, seek medical advice. People with questions about their medicines or seeking general information about side effects can also call the NPS Medicines Line on 1300 633 424 (Monday-Friday, 9am-5pm AEST). To report possible side effects call the Adverse Medicine Events (AME) line on 1300 134 237 from anywhere in Australia (Monday–Friday, 9am–5pm AEST).

  • Rossi S, ed. Australian Medicines Handbook [online]. Adelaide: AMH, July 2012.
  • Sweetman S, ed. Martindale: The complete drug reference [online]. London: Pharmaceutical Press (accessed 18 October 2011).
  • Antibiotic Expert Group. Therapeutic Guidelines: Antibiotic version 14; Erythromycin. Melbourne: Therapeutic Guidelines Limited, 2012 (accessed 27 March 2012).