Diltiazem and Dorzolamide and timolol interaction
Diltiazem and Dorzolamide and timolol: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Diltiazem (DILTIAZEM HYDROCHLORIDE in SODIUM CHLORIDE) label · effective 2025-04-15
• Concomitant administration with IV beta-blockers.
Beta-blockers Increased risk of bradycardia, AV block, and depression of contractility.
Beta-blocker may need to be decreased [see Warnings and Precautions (5.1, 5.2)].
• Beta-Blockers: Monitor for bradycardia, AV block, and depression of contractility.
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.
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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.