Cardiac safety of ophthalmic timolol.

Article Details

Citation

Maenpaa J, Pelkonen O

Cardiac safety of ophthalmic timolol.

Expert Opin Drug Saf. 2016 Nov;15(11):1549-1561. doi: 10.1080/14740338.2016.1225718. Epub 2016 Aug 31.

PubMed ID
27534869 [ View in PubMed
]
Abstract

INTRODUCTION: It is generally believed that topical administration of eye drops safeguards against harmful systemic effects. However, about 80% of the drug in the ophthalmic products is systemically absorbed and the first-pass metabolism is avoided. Ophthalmic timolol is widely prescribed in the treatment of glaucoma either alone or in the combination eye drop products, many of which have been launched fairly recently. Ophthalmic timolol may cause serious adverse effects such as symptomatic bradycardia, various conduction disorders in the heart, orthostatic hypotension, syncope and falls. Areas covered: In this review we document a number of factors associated with the properties of ophthalmic timolol and specific features of a patient, which may jeopardize patient's cardiac safety even after topical treatment. Expert opinion: Plasma timolol levels are correlated with cardiovascular adverse effects in patients, since timolol is mainly metabolized by cytochrome P450 2D6 (CYP2D6) enzyme in the liver. Patients who are lacking the functional CYP2D6 or who are concomitantly using potent CYP2D6 inhibitor drugs (e.g. paroxetine or fluoxetine) or verapamil or other beta-blockers are at risk of getting serious cardiac adverse effects. Prior to treatment initiation, ECG should be always performed and CYP2D6 genotyping should be considered, if routinely available.

DrugBank Data that Cites this Article

Drugs
Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
TimololCytochrome P450 2D6ProteinHumans
Unknown
Substrate
Details
Drug Interactions
DrugsInteraction
Acebutolol
Verapamil
The risk or severity of adverse effects can be increased when Verapamil is combined with Acebutolol.
Atenolol
Verapamil
The risk or severity of adverse effects can be increased when Verapamil is combined with Atenolol.
Betaxolol
Verapamil
The risk or severity of adverse effects can be increased when Verapamil is combined with Betaxolol.
Bisoprolol
Verapamil
The risk or severity of adverse effects can be increased when Verapamil is combined with Bisoprolol.
Carteolol
Verapamil
The risk or severity of adverse effects can be increased when Verapamil is combined with Carteolol.