Drug interactions
Chlorthalidone + Olanzapine / samidorphan
Severity: Moderate
Chlorthalidone 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, so combining it with an antihypertensive diuretic such as chlorthalidone may enhance blood pressure lowering. Dizziness, syncope and falls are possible, particularly at initiation.
What this interaction means in plain words
Chlorthalidone 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 antagonism and diuretic-induced volume depletion.
What to do
Monitor blood pressure and orthostatic symptoms when starting or increasing olanzapine/samidorphan. Reduce chlorthalidone 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 Chlorthalidone
Frequently asked questions
Can I take Chlorthalidone with Olanzapine / samidorphan?
MediHelp rates the interaction as moderate. Chlorthalidone 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, so combining it with an antihypertensive diuretic such as chlorthalidone may enhance blood pressure lowering. Dizziness, syncope and falls are possible, particularly at initiation.
How serious is the interaction between Chlorthalidone 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 and orthostatic symptoms when starting or increasing olanzapine/samidorphan. Reduce chlorthalidone dose if hypotension occurs.
What other medicines interact with Chlorthalidone?
MediHelp also lists interactions of Chlorthalidone with, for example, Amifostine, Atenolol-chlorthalidone, Candesartan-hydrochlorothiazide. The full list is on the Chlorthalidone page.
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