Diltiazem and Dorzolamide and timolol interaction
Diltiazem and Dorzolamide and timolol: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Diltiazem (Cardizem LA) label · effective 2025-11-11
Concomitant use of diltiazem with beta-blockers or digitalis may result in additive effects on cardiac conduction.
• Beta-blockers, digitalis, and other agents known to impair cardiac contractility and conduction may increase risk for hypotension, bradycardia, and heart failure.
Experience with the use of diltiazem in combination with beta-blockers in patients with impaired ventricular function is limited.
From the Dorzolamide and timolol (COSOPT PF) label · effective 2026-05-13
Oral or intravenous calcium antagonists may cause atrioventricular conduction disturbances, left ventricular failure, and hypotension.
Digitalis and calcium antagonists may have additive effects in prolonging atrioventricular conduction time.
Calcium Antagonists Caution should be used in the coadministration of beta-adrenergic blocking agents, such as COSOPT PF, and oral or intravenous calcium antagonists because of possible atrioventricular conduction disturbances, left ventricular failure, and hypotension.
Digitalis and Calcium Antagonists The concomitant use of beta-adrenergic blocking agents with digitalis and calcium antagonists may have additive effects in prolonging atrioventricular conduction time.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.