Can you take other medicines with ondansetron?

Medically reviewed by Dr Roger Henderson, words by Rita Ghelani (BPharm, MRPharmS)
·2-min read
Photo credit: Navinpeep - Getty Images
Photo credit: Navinpeep - Getty Images

From Netdoctor

Ondansetron is an anti-sickness medicine (sometimes called an antiemetic) that is mainly used in hospitals to help with nausea and vomiting associated with cancer treatments or operations under general anaesthetics.

Here's everything you need to know about taking other medicines with ondansetron, including which it makes less effective and when it might increase the chance of side effects:

What medicines can't you take with ondansetron?

It's important to tell your pharmacist if you're already taking any medicines, including herbal medicines and those bought without a prescription, before you start treatment with ondansetron.

Similarly, always check with your pharmacist before taking any new medicines while you're taking ondansetron, to make sure that the combination is safe.

Ondansetron should not be used in combination with apomorphine (used to treat Parkinson's disease).

Does ondansetron make any medicines less effective?

Ondansetron may reduce the painkilling effect of tramadol.

The following medicines may increase the removal of ondansetron from the body and could therefore make it less effective:

  • carbamazepine

  • fosphenytoin

  • phenobarbital

  • phenytoin

  • rifampicin.

Does ondansetron affect any other medicines?

There may be an increased risk of a side effect called the serotonin syndrome if ondansetron is taken with SSRI antidepressants such as citalopram, fluoxetine or paroxetine.

There may be an increased risk of developing an abnormal heart rhythm, seen as a 'prolonged QT interval' on an ECG, if ondansetron is taken with other medicines that can affect the heart, such as the following:

  • antiarrhythmics (medicines to treat abnormal heartbeats), such as amiodarone, procainamide, disopyramide, sotalol

  • anti-cancer medicines that can affect the heart, for example trastuzumab or anthracyclines such as doxorubicin or daunorubicin

  • the antihistamines astemizole, mizolastine or terfenadine

  • arsenic trioxide

  • atomoxetine

  • certain antidepressants, such as citalopram, escitalopram, clomipramine

  • certain antimalarials, such a§s halofantrine, chloroquine, quinine, mefloquine, Riamet

  • certain antipsychotics, such as thioridazine, chlorpromazine, sertindole, haloperidol

  • cisapride

  • certain antimicrobials, eg erythromycin given by injection, telithromycin, levofloxacin, moxifloxacin, voriconazole or pentamidine

  • medicines that can cause the amount of potassium in the blood to drop too low, for example diuretics such as furosemide, bendroflumethiazide, acetazolamide

  • methadone

  • panobinostat

  • sildenafil

  • tolterodine

  • vandetanib

  • vardenafil.

Last updated: 22.11.2020

You Might Also Like