Does Timolol Interact with Timolol Hemihydrate?
Timolol and Timolol Hemihydrate have a moderate drug interaction according to U.S. FDA drug labeling data. (7.4) Potentiated systemic beta-blockade (e.g., decreased heart rate) has been reported during combined treatment with quinidine and timolol. (7.5) 7.1 Beta-Adrenergic Blocking Agents Patients who are receiving a beta-adrenergic blocking agent orally and timolol maleate ophthalmic solution should be observed for potential additive effects of beta-blockade, both systemic and on intraocular pressure. 7.2 Calcium Antagonists Caution should be used in the co-administration of beta-adrenergic blocking agents, such as timolol maleate ophthalmic solution, and oral or intravenous calcium antagonists because of possible atrioventricular conduction disturbances, left ventricular failure, and hypotension. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Moderate
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
What To Tell Your Doctor or Pharmacist
If you are taking Timolol and your doctor is considering prescribing Timolol Hemihydrate (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider