Drug interactions
Doxepin + Quetiapine
Severity: Moderate
Doxepin and Quetiapine: moderate 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
Both drugs are sedating and can prolong the QT interval, so combined use increases drowsiness, orthostatic hypotension and arrhythmia risk. Anticholinergic effects such as dry mouth, constipation and confusion may also add up.
What this interaction means in plain words
Doxepin and Quetiapine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Doxepin belongs to Dermatology; Quetiapine belongs to Central Nervous System.
Why it happens
Additive histamine H1 and alpha-adrenergic blockade, anticholinergic effects and QT prolongation.
What to do
Use the lowest effective doses, check ECG in patients with cardiac risk factors, and correct electrolytes. Monitor sedation, blood pressure and anticholinergic effects, especially in the elderly.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Quetiapine
- Adagrasib + Quetiapine Major
- Amiodarone + Quetiapine Major
- Amisulpride + Quetiapine Major
- Amoxapine + Quetiapine Major
- Anagrelide + Quetiapine Major
- Apalutamide + Quetiapine Major
Other interactions of Doxepin
- Doxepin + Isocarboxazid Contraindicated
- Doxepin + Phenelzine Contraindicated
- Doxepin + Procarbazine Contraindicated
- Doxepin + Safinamide Contraindicated
- Doxepin + Selegiline Contraindicated
- Doxepin + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Doxepin with Quetiapine?
MediHelp rates the interaction as moderate. Doxepin and Quetiapine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Both drugs are sedating and can prolong the QT interval, so combined use increases drowsiness, orthostatic hypotension and arrhythmia risk. Anticholinergic effects such as dry mouth, constipation and confusion may also add up.
How serious is the interaction between Doxepin and Quetiapine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective doses, check ECG in patients with cardiac risk factors, and correct electrolytes. Monitor sedation, blood pressure and anticholinergic effects, especially in the elderly.
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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