Drug interactions
Captopril-hydrochlorothiazide + Promethazine
Severity: Minor
Captopril-hydrochlorothiazide and Promethazine: minor 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
Promethazine has alpha-blocking and sedative properties that can lower blood pressure. Combined with an ACE inhibitor and thiazide, hypotension and dizziness may be more pronounced.
What this interaction means in plain words
Captopril-hydrochlorothiazide and Promethazine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Captopril-hydrochlorothiazide belongs to Cardiovascular; Promethazine belongs to Respiratory.
Why it happens
Additive hypotensive effect from alpha-adrenergic blockade and central sedation with ACE inhibition and diuresis.
What to do
Monitor blood pressure and counsel patients on rising slowly. Adjust doses if symptomatic hypotension occurs.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Captopril-hydrochlorothiazide
- Aliskiren + Captopril-hydrochlorothiazide Contraindicated
- Captopril-hydrochlorothiazide + Dofetilide Contraindicated
- Captopril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Aceclofenac + Captopril-hydrochlorothiazide Major
- Aldesleukin + Captopril-hydrochlorothiazide Major
- Amifostine + Captopril-hydrochlorothiazide Major
Other interactions of Promethazine
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Frequently asked questions
Can I take Captopril-hydrochlorothiazide with Promethazine?
MediHelp rates the interaction as minor. Captopril-hydrochlorothiazide and Promethazine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Promethazine has alpha-blocking and sedative properties that can lower blood pressure. Combined with an ACE inhibitor and thiazide, hypotension and dizziness may be more pronounced.
How serious is the interaction between Captopril-hydrochlorothiazide and Promethazine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure and counsel patients on rising slowly. Adjust doses if symptomatic hypotension occurs.
What other medicines interact with Captopril-hydrochlorothiazide?
MediHelp also lists interactions of Captopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Sacubitril / valsartan. The full list is on the Captopril-hydrochlorothiazide page.
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