Drug interactions
Cimetidine + Lomitapide
Severity: Major
Cimetidine and Lomitapide: major interaction.
Last updated Sources: US FDA label
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
Cimetidine, a weak CYP3A4 inhibitor, may raise lomitapide levels and increase risk of hepatotoxicity and gastrointestinal adverse effects. Lomitapide exposure is highly sensitive to CYP3A4 inhibition.
What this interaction means in plain words
Cimetidine and Lomitapide 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.
Cimetidine belongs to Gastrointestinal Tract; Lomitapide belongs to Cardiovascular.
Why it happens
Inhibition of CYP3A4 metabolism of lomitapide increases its plasma levels.
What to do
Limit lomitapide dose to the label-recommended maximum with weak inhibitors, or choose famotidine instead. Monitor liver enzymes and tolerability.
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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References
Other interactions of Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Other interactions of Lomitapide
- Aprepitant + Lomitapide Contraindicated
- Clarithromycin + Lomitapide Contraindicated
- Crizotinib + Lomitapide Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Efavirenz + Lomitapide Contraindicated
- Ensitrelvir + Lomitapide Contraindicated
Frequently asked questions
Can I take Cimetidine with Lomitapide?
MediHelp rates the interaction as major. Cimetidine and Lomitapide 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. Cimetidine, a weak CYP3A4 inhibitor, may raise lomitapide levels and increase risk of hepatotoxicity and gastrointestinal adverse effects. Lomitapide exposure is highly sensitive to CYP3A4 inhibition.
How serious is the interaction between Cimetidine and Lomitapide?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Limit lomitapide dose to the label-recommended maximum with weak inhibitors, or choose famotidine instead. Monitor liver enzymes and tolerability.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
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