Drug interactions
Cobicistat + Nortriptyline
Severity: Major
Cobicistat and Nortriptyline: 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
Cobicistat strongly inhibits CYP3A and CYP2D6, which can raise nortriptyline concentrations. This may lead to anticholinergic effects, sedation, and cardiac conduction abnormalities.
What this interaction means in plain words
Cobicistat and Nortriptyline 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.
Cobicistat belongs to Miscellaneous; Nortriptyline belongs to Central Nervous System.
Why it happens
Inhibition of CYP2D6 and CYP3A-mediated metabolism of nortriptyline.
What to do
Start nortriptyline at a low dose and titrate to response, and monitor ECG and tricyclic levels. Reduce the dose if toxicity occurs.
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 Nortriptyline
- Disopyramide + Nortriptyline Contraindicated
- Dofetilide + Nortriptyline Contraindicated
- Dronedarone + Nortriptyline Contraindicated
- Ibutilide + Nortriptyline Contraindicated
- Isocarboxazid + Nortriptyline Contraindicated
- Methylene blue + Nortriptyline Contraindicated
Other interactions of Cobicistat
- Alfuzosin + Cobicistat Contraindicated
- Apalutamide + Cobicistat Contraindicated
- Cobicistat + Colchicine Contraindicated
- Cobicistat + Dronedarone Contraindicated
- Cobicistat + Eletriptan Contraindicated
- Cobicistat + Eplerenone Contraindicated
Frequently asked questions
Can I take Cobicistat with Nortriptyline?
MediHelp rates the interaction as major. Cobicistat and Nortriptyline 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. Cobicistat strongly inhibits CYP3A and CYP2D6, which can raise nortriptyline concentrations. This may lead to anticholinergic effects, sedation, and cardiac conduction abnormalities.
How serious is the interaction between Cobicistat and Nortriptyline?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start nortriptyline at a low dose and titrate to response, and monitor ECG and tricyclic levels. Reduce the dose if toxicity occurs.
What other medicines interact with Nortriptyline?
MediHelp also lists interactions of Nortriptyline with, for example, Disopyramide, Dofetilide, Dronedarone. The full list is on the Nortriptyline page.
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