Drug interactions
Hydrochlorothiazide + Olanzapine / samidorphan
Severity: Moderate
Hydrochlorothiazide and Olanzapine / samidorphan: 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
Olanzapine can cause orthostatic hypotension and may add to the blood pressure lowering of hydrochlorothiazide. Patients may experience dizziness or syncope, especially at the start of therapy or after dose increases.
What this interaction means in plain words
Hydrochlorothiazide and Olanzapine / samidorphan 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.
Why it happens
Additive hypotension from olanzapine alpha-1 adrenergic blockade and diuretic-induced volume depletion.
What to do
Monitor blood pressure, including orthostatic readings, and reduce the antihypertensive dose if hypotension occurs.
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 Hydrochlorothiazide
Frequently asked questions
Can I take Hydrochlorothiazide with Olanzapine / samidorphan?
MediHelp rates the interaction as moderate. Hydrochlorothiazide and Olanzapine / samidorphan 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. Olanzapine can cause orthostatic hypotension and may add to the blood pressure lowering of hydrochlorothiazide. Patients may experience dizziness or syncope, especially at the start of therapy or after dose increases.
How serious is the interaction between Hydrochlorothiazide and Olanzapine / samidorphan?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure, including orthostatic readings, and reduce the antihypertensive dose if hypotension occurs.
What other medicines interact with Hydrochlorothiazide?
MediHelp also lists interactions of Hydrochlorothiazide with, for example, Dofetilide, Amifostine, Amiodarone. The full list is on the Hydrochlorothiazide page.
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