Drug interactions
Hydrochlorothiazide-telmisartan + Timolol
Severity: Moderate
Hydrochlorothiazide-telmisartan and Timolol: 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
Timolol, even as a systemic beta-blocker, adds to the antihypertensive effect of the combination and may cause bradycardia or hypotension. Beta-blockers can also slightly raise potassium, adding to the effect of telmisartan. Ophthalmic timolol has lower but not absent systemic exposure.
What this interaction means in plain words
Hydrochlorothiazide-telmisartan and Timolol 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.
Hydrochlorothiazide-telmisartan belongs to Cardiovascular; Timolol belongs to Cardiovascular.
Why it happens
Additive blood pressure lowering through different mechanisms, with minor additive potassium retention from beta-blockade and angiotensin receptor blockade.
What to do
Monitor blood pressure, heart rate and serum potassium when starting or adjusting therapy and reduce doses if symptomatic hypotension or bradycardia 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-telmisartan
- Aliskiren + Hydrochlorothiazide-telmisartan Contraindicated
- Dofetilide + Hydrochlorothiazide-telmisartan Contraindicated
- Hydrochlorothiazide-telmisartan + Sparsentan Contraindicated
- Aldesleukin + Hydrochlorothiazide-telmisartan Major
- Amifostine + Hydrochlorothiazide-telmisartan Major
- Amiloride + Hydrochlorothiazide-telmisartan Major
Other interactions of Timolol
- Acebutolol + Timolol Major
- Albuterol + Timolol Major
- Aldesleukin + Timolol Major
- Amifostine + Timolol Major
- Amiodarone + Timolol Major
- Arformoterol + Timolol Major
Frequently asked questions
Can I take Hydrochlorothiazide-telmisartan with Timolol?
MediHelp rates the interaction as moderate. Hydrochlorothiazide-telmisartan and Timolol 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. Timolol, even as a systemic beta-blocker, adds to the antihypertensive effect of the combination and may cause bradycardia or hypotension. Beta-blockers can also slightly raise potassium, adding to the effect of telmisartan. Ophthalmic timolol has lower but not absent systemic exposure.
How serious is the interaction between Hydrochlorothiazide-telmisartan and Timolol?
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, heart rate and serum potassium when starting or adjusting therapy and reduce doses if symptomatic hypotension or bradycardia occurs.
What other medicines interact with Hydrochlorothiazide-telmisartan?
MediHelp also lists interactions of Hydrochlorothiazide-telmisartan with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Hydrochlorothiazide-telmisartan page.
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