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Drug interactions

Cobicistat + Quetiapine

Severity: Major

Cobicistat and Quetiapine: 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 is a strong CYP3A4 inhibitor and can sharply increase quetiapine concentrations. This may cause marked sedation, hypotension and QT prolongation.

What this interaction means in plain words

Cobicistat and Quetiapine 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; Quetiapine belongs to Central Nervous System.

Evidence level: High

Why it happens

CYP3A4 inhibition by cobicistat reduces quetiapine metabolism.

What to do

Reduce the quetiapine dose to about one-sixth of the current dose and monitor for sedation, hypotension and QTc. Retitrate quetiapine after cobicistat is discontinued.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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References

Frequently asked questions

Can I take Cobicistat with Quetiapine?

MediHelp rates the interaction as major. Cobicistat and Quetiapine 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 is a strong CYP3A4 inhibitor and can sharply increase quetiapine concentrations. This may cause marked sedation, hypotension and QT prolongation.

How serious is the interaction between Cobicistat and Quetiapine?

MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reduce the quetiapine dose to about one-sixth of the current dose and monitor for sedation, hypotension and QTc. Retitrate quetiapine after cobicistat is discontinued.

What other medicines interact with Quetiapine?

MediHelp also lists interactions of Quetiapine with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Quetiapine page.

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