Drug interactions
Doxazosin + Fosinopril-hydrochlorothiazide
Severity: Moderate
Doxazosin and Fosinopril-hydrochlorothiazide: 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 agents lower blood pressure, and the combination can cause excessive hypotension, especially after the first doxazosin dose or dose increases. Dizziness, syncope and falls are the main concerns.
What this interaction means in plain words
Doxazosin and Fosinopril-hydrochlorothiazide 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.
Doxazosin belongs to Genitourinary; Fosinopril-hydrochlorothiazide belongs to Cardiovascular.
Why it happens
Additive vasodilation and volume reduction through alpha-1 blockade, ACE inhibition and diuresis.
What to do
Start doxazosin at a low dose at bedtime and titrate gradually. Monitor blood pressure including orthostatic readings.
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 Fosinopril-hydrochlorothiazide
- Aliskiren + Fosinopril-hydrochlorothiazide Contraindicated
- Dofetilide + Fosinopril-hydrochlorothiazide Contraindicated
- Fosinopril-hydrochlorothiazide + Protein a column Contraindicated
- Fosinopril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Aldesleukin + Fosinopril-hydrochlorothiazide Major
- Amifostine + Fosinopril-hydrochlorothiazide Major
Other interactions of Doxazosin
- Alfuzosin + Doxazosin Major
- Amifostine + Doxazosin Major
- Avanafil + Doxazosin Major
- Doxazosin + Dutasteride-tamsulosin Major
- Doxazosin + Phentolamine Major
- Doxazosin + Prazosin Major
Frequently asked questions
Can I take Doxazosin with Fosinopril-hydrochlorothiazide?
MediHelp rates the interaction as moderate. Doxazosin and Fosinopril-hydrochlorothiazide 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 agents lower blood pressure, and the combination can cause excessive hypotension, especially after the first doxazosin dose or dose increases. Dizziness, syncope and falls are the main concerns.
How serious is the interaction between Doxazosin and Fosinopril-hydrochlorothiazide?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start doxazosin at a low dose at bedtime and titrate gradually. Monitor blood pressure including orthostatic readings.
What other medicines interact with Fosinopril-hydrochlorothiazide?
MediHelp also lists interactions of Fosinopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Protein a column. The full list is on the Fosinopril-hydrochlorothiazide page.
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