What is timolol and how does it work (mechanism of action)?
Timolol maleate is a beta1 and beta2 (nonselective) adrenergic receptor inhibitor that does not have significant intrinsic sympathomimetic, direct myocardial depressant, or local anesthetic (membrane-stabilizing) activity. Timolol GFS, when applied topically to the eye, has the action of reducing elevated, as well as normal, intraocular pressure, whether or not accompanied by glaucoma.
Elevated intraocular pressure is a major risk factor in the pathogenesis of glaucomatous visual field loss and optic nerve damage. The precise mechanism of the ocular hypotensive action of Timolol GFS is not clearly established at this time.
Is timolol available as a generic drug?
Do I need a prescription for timolol?
What are the uses for timolol?
- Timolol is prescribed to lower
blood pressure in patients
with high blood pressure (hypertension).
- It also is used to reduce angina (heart
pain), and to stabilize irregular heartbeats (arrhythmias) and prevent
headaches. Off label uses include the treatment of
and mitral valve prolapse.
What are the side effects of timolol?
Minor side effects of timolol include:
Major side effects include:
- vivid dreams,
- memory loss,
- slow heart rate,
- low blood pressure,
- blueness of the hands or feet,
- sore throat,
- shortness of breath, or
What is the dosage for timolol?
The range of dosing for adults is 10 to 60 mg per day.
In the U.S., 1 in every 4 deaths is caused by heart disease.
Which drugs or supplements interact with timolol?
- The concurrent use of timolol and
may cause rebound
hypertension upon abrupt discontinuation of clonidine. It is
advisable, therefore, to stop the beta adrenergic blocking drug by several days
before gradually withdrawing clonidine.
- Fenoldopam (Corlopam), which is used for
the treatment of severe
hypertension should not be taken together with timolol
as the combination may increase the risk of
hypotension due to additive effects
of the two
lowering blood pressure.
- Close observation should be carried out when timolol is administered to
patients receiving catecholamine-depleting drugs such as
because of possible additive effects and the production of
hypotension and/or a
markedly slow heartbeat, which may produce
hypotension (dizziness upon standing).
- Concurrent use of
NSAIDs with timolol may
antihypertensive action of beta-blockers to be decreased. This occurs
because prostaglandins are important in controlling blood pressure.
Is timolol safe to take if I’m pregnant or breastfeeding?
- There are no adequate studies in pregnant women. Timolol should be
pregnancy only if the potential benefit justifies the potential
- Timolol has been detected in
human milk and has a potential
for adverse events in infants.
What else should I know about timolol?
What preparations of timolol are available?
Tablets: 5, 10, and 20 mg.
How should I keep timolol stored?
Timolol should be stored at room temperature, 15 C – 30 C (59 F – 86 F) and kept in a tightly sealed container protected from light