Drug interactions
Macimorelin + Ondansetron
Severity: Major
Macimorelin and Ondansetron: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Macimorelin has a modest QT-prolonging effect and ondansetron also lengthens the QT interval. Used together they may add to arrhythmia risk, and an abnormal ECG could confound the diagnostic test.
What this interaction means in plain words
Macimorelin and Ondansetron can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Macimorelin belongs to Endocrine; Ondansetron belongs to Gastrointestinal Tract.
Why it happens
Additive pharmacodynamic QT prolongation.
What to do
Avoid giving ondansetron around the time of the macimorelin test and allow adequate washout before testing. Choose an alternative antiemetic if one is needed.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Ondansetron
- Apomorphine + Ondansetron Contraindicated
- Ondansetron + Thioridazine Contraindicated
- Ondansetron + Vandetanib Contraindicated
- Adagrasib + Ondansetron Major
- Amiodarone + Ondansetron Major
- Amisulpride + Ondansetron Major
Other interactions of Macimorelin
Frequently asked questions
Can I take Macimorelin with Ondansetron?
MediHelp rates the interaction as major. Macimorelin and Ondansetron can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Macimorelin has a modest QT-prolonging effect and ondansetron also lengthens the QT interval. Used together they may add to arrhythmia risk, and an abnormal ECG could confound the diagnostic test.
How serious is the interaction between Macimorelin and Ondansetron?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid giving ondansetron around the time of the macimorelin test and allow adequate washout before testing. Choose an alternative antiemetic if one is needed.
What other medicines interact with Ondansetron?
MediHelp also lists interactions of Ondansetron with, for example, Apomorphine, Thioridazine, Vandetanib. The full list is on the Ondansetron page.
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