timolol (Betimol)

  • Pharmacy Author:
    Annette (Gbemudu) Ogbru, PharmD, MBA

    Dr. Gbemudu received her B.S. in Biochemistry from Nova Southeastern University, her PharmD degree from University of Maryland, and MBA degree from University of Baltimore. She completed a one year post-doctoral fellowship with Rutgers University and Bristol Myers Squibb.

  • Medical and Pharmacy Editor: Jay W. Marks, MD
    Jay W. Marks, MD

    Jay W. Marks, MD

    Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

What is timolol and how does it work (mechanism of action)?

Timolol GFS 0.25% and 0.5% are indicated for the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma.

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?

Yes

Do I need a prescription for timolol?

Yes

What are the uses for timolol?

What are the side effects of timolol?

Minor side effects of timolol include:

Major side effects include:

What is the dosage for timolol?

The range of dosing for adults is 10 to 60 mg per day.

SLIDESHOW

Heart Disease: Causes of a Heart Attack See Slideshow

Which drugs or supplements interact with timolol?

  • The concurrent use of timolol and clonidine (Catapres), 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 drugs in lowering blood pressure.
  • Close observation should be carried out when timolol is administered to patients receiving catecholamine-depleting drugs such as reserpine (Harmonyl) because of possible additive effects and the production of hypotension and/or a markedly slow heartbeat, which may produce dizziness, syncope, or postural hypotension (dizziness upon standing).
  • Concurrent use of NSAIDs with timolol may cause the 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 used during pregnancy only if the potential benefit justifies the potential risk.
  • 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

Summary

Timolol (Betimol) is a first-generation beta-blocker drug. Timolol is prescribed for the treatment of high blood pressure, angina, heart attacks, and migraine headache prevention. Off label uses include treatment for cardiomyopathy and mitral valve prolapse. Side effects include fatigue, insomnia, nausea, vomiting, diarrhea, abdominal cramps. Drug interactions, warnings and precautions, and pregnancy and breastfeeding safety information should be reviewed prior to taking this medication.

Treatment & Diagnosis

Medications & Supplements

Prevention & Wellness

QUESTION

In the U.S., 1 in every 4 deaths is caused by heart disease. See Answer

Health Solutions From Our Sponsors

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

See more info: timolol on RxList
Medically Reviewed on 9/5/2019
References
FDA Prescribing Information
CONTINUE SCROLLING FOR RELATED SLIDESHOW