NZ Formulary



What does it do?

Erythromycin is an antibiotic used to treat and prevent bacterial infections, and sometimes other conditions.

Before you start

  • Tell your doctor if you have heart or liver problems.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Your doctor may do a heart test (ECG) before you start and while you are taking erythromycin.
  • Tell your doctor if you have phenylketonuria (PKU). The erythromycin liquid may contain aspartame (a source of phenylalanine).

How should you take it?

Take erythromycin regularly as directed. You can take it with or without food. Keep taking it until the course is finished, even if you start to feel better.
Tablet: Take with a glass of water.
Liquid: Shake well before use. Measure each dose carefully with an oral syringe or measuring spoon.

What if you forget a dose?

Take the missed dose as soon as possible and continue as directed.

Can you take other medicines?

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products (e.g. St John's wort) or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Fast or irregular heartbeat, fainting

Symptoms of liver problems including: yellow skin or eyes, itching, dark urine, pale bowel motions, abdominal pain

Tell your doctor immediately

Severe or persistent diarrhoea, abdominal pain

Hearing loss, ringing in the ears

Tell your doctor

Stomach upset

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Store erythromycin liquid as directed. Once the course is finished, take any leftover liquid back to your pharmacy.