Interactions with erythromycin

What are the interactions with erythromycin?

Tell your doctor about all the medicines you are taking.

Erythromycin can interact with many different medicines so it is very important that you tell your health professional about all the medicines you are taking — including prescription, over-the-counter and complementary medicines (herbal, ‘natural’, and vitamin and mineral supplements). This is because all medicines, including herbal and natural medicines, can cause side effects and may interact with erythromycin.

Do not take erythromycin if you are taking medicines containing any of the active ingredients below.

  • Atorvastatin and simvastatin (used to treat high cholesterol): erythromycin may increase the concentration of atorvastatin or simvastatin in your blood. You may need to stop taking atorvastatin or simvastatin for a while, or change to another medicine
  • Carbamazepine (used to treat epilepsy and bipolar disorder): erythromycin increases the amount of carbamazepine in the blood, and this can increase the chance of side effects. These two medicines should not be taken together.
  • Cilostazol (used to treat circulatory problems [peripheral vascular disease]): erythromycin increases the amount of cilostazol in your blood, increasing the chance of side effects, including bleeding. These two medicines should not be taken together if possible.
  • Cisapride (used to treat stomach acid reflux): this medicine is not available in Australia, but erythromycin and cisapride should not be taken together. This is because both erythromycin and cisapride can affect heart rate. Erythromycin increases the amount of cisapride in the blood, increasing the risk of the effect on heart rate.
  • Cyclosporin, everolimus, sirolimus and tacrolimus (used to suppress the immune system, e.g. to prevent transplant rejection): erythromycin increases the amount of these medicines in the blood, and increases the chance of side effects. Erythromycin should not be taken together with these medicines if possible.
  • Colchicine (used to prevent and treat gout): erythromycin may increase the amount of colchicine in the blood. This increases the toxicity of colchicine (which can be fatal). These two medicines should not be taken together if possible.
  • Ergot alkaloids (e.g. ergotamine used to treat migraines): erythromycin increases the amount of these medicines in your blood, which can be toxic. Erythromycin should not be taken with these medicines.
  • Disopyramide (used to treat irregular heart beat): erythromycin may increase the concentration of disopyramide in your blood and increase the risk of side effects. These two medicines should not be taken together if possible.
  • Theophylline (used to treat severe asthma and COPD): erythromycin may increase the amount of theophylline in your blood and increases the risk of side effects. Theophylline can also decrease erythromycin concentration, affecting how well it works. These two medicines should not be taken together if possible.
  • Triazolam and midazolam (triazolam is a benzodiazepine used to treat sleeplessness [insomnia]; midazolam is used as a sedative during short medical procedures): erythromycin may increase the concentration of triazolam or midozalam in the blood and increase its sedative and other side effects. Erythromycin should not be taken with these medicines if possible.
  • Verapamil (used to treat high blood pressure and heart problems) may increase the amount of erythromycin in your blood, increasing the chance of affecting your heart rate. Erythromycin itself can increase the amount of verapamil in your blood, which increases the chance of verapamil levels being toxic to the heart (cardiotoxicity), and further affecting heart rate. These medicines should not be taken together if possible.

Tell your health professional if you are taking medicines containing any of the following active ingredients as they may need to adjust your dose of these medicines.

  • Bromocriptine (used to treat Parkinson’s disease): erythromycin may increase the amount of bromocriptine in the blood. This may increase the chance of side effects. You may need to take a lower dose of bromocriptine.
  • Buspirone (used to treat anxiety disorders): erythromycin increases the amount of buspirone in your blood, which may increase the chance of side effects. You may need a lower dose of buspirone if you also need to take erythromycin.
  • Cabergoline (used to treat Parkinson’s disease): erythromycin may increase the amount of cabergoline in your blood. This may increase the effect of the medicines and increase the chance of side effects. You may need to take a lower dose of cabergoline.
  • Digoxin (used to treat congestive heart failure): erythromycin may increase the amount of digoxin in your system, so your doctor may need to alter your dose of digoxin.
  • Eletriptan (used to treat migraine): erythromycin increases the amount of eletriptan in the blood and increases the risk of reduced blood supply to the heart (ischaemia). If you have been taking erythromycin, you must wait 48 hours before taking eletriptan.
  • Eplerenone (used to treat heart failure): erythromycin increases the amount of eplerenone in the blood and increases the risk of side effects. You may need a smaller dose of eplerenone.
  • Felodipine (used to treat high blood pressure): erythromycin may increase the amount of felodipine in your blood, which may increase the chance of side effects of felodipine. You may need a smaller dose of felodipine.
  • Lignocaine (a local anaesthetic): erythromycin can increase the amount of lignocaine in your blood, which may increase the chance of side effects of lignocaine.
  • Quetiapine (used to treat anxiety, depression, schizophrenia and bipolar disorder): erythromycin increases the amount of quetiapine in your blood and increases the risk of side effects. You may need a smaller dose of quetiapine.
  • Sildenafil and vardenafil (used to treat erectile dysfunction): erythromycin may increase the concentration of these medicines, increasing the risk of side effects. You may need a lower dose of sildenafil or vardenafil.
  • Vinblastine (used to treat some types of cancer including breast cancer): erythromycin can prevent vinblastine being used up by the body, which can increase the amount of vinblastine in the blood, increasing its side effects. These medicines should not be taken at the same time. Erythromycin can be given 48 hours after vinblastine.
  • Warfarin (used to treat and prevent blood clots): erythromycin can increase the blood-thinning effect of warfarin and increase the risk of bleeding. Your dose of warfarin may need to be adjusted and you may need to have additional INR tests and be monitored for signs of bleeding.

Medicinewise tip

To check if your medicine contains this active ingredient, look on the packaging of your medicine for the active ingredient name, or use our Medicines Finder.

Can I drink alcohol if I am taking erythromycin?

Drinking alcohol in moderation is unlikely to interact with erythromycin or cause additional side effects.

Find out more about drinking alcohol when you are taking antibiotics.

Will erythromycin affect my contraceptive?

Erythromycin won’t affect your hormone contraceptive.

Rifampicin and rifabutin are the only types of antibiotic that are known to interact with some forms of hormone contraceptives, such as the combined contraceptive pill, making it less effective.

Find out more about antibiotics and contraception.

Phone for medicines information

Call NPS Medicines Line on 1300 MEDICINE (1300 633 424) to get information about your prescription, over-the-counter and complementary medicines (herbal, ‘natural’, vitamins and mineral supplements) from a pharmacist. Your call will be answered by healthdirect Australia.

References
  • 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).