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Generic name: timolol [ TIH-mo-lol ]
Brand name: Blocadren
Dosage form: oral tablet (10 mg; 20 mg; 5 mg)
Drug class: Non-cardioselective beta blockers

Medically reviewed by on Jan 15, 2024. Written by Cerner Multum.

What is timolol?

Timolol is used to treat hypertension (high blood pressure). Timolol is sometimes given with other blood pressure medication.

Timolol is also used to lower the risk of death after a heart attack, or to lower the risk of having another heart attack.

Timolol is also used to prevent migraine headaches.

Timolol may also be used for purposes not listed in this medication guide.

Timolol side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Timolol may cause serious side effects. Call your doctor at once if you have:

Common side effects of timolol may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Use only as directed. Tell your doctor if you use other medicines or have other medical conditions or allergies.

Before taking this medicine

You should not use timolol if you are allergic to it, or if you have:

Tell your doctor if you have ever had:

It is not known whether timolol will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Timolol can pass into breast milk and may harm a nursing baby. You should not breastfeed while using this medicine.

Timolol is not approved for use by anyone younger than 18 years old.

How should I take timolol?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Your blood pressure will need to be checked often.

If you need surgery, tell the surgeon ahead of time that you are using timolol. You may need to stop using the medicine for a short time.

You should not stop using timolol suddenly. Stopping suddenly may make your condition worse.

If you are being treated for high blood pressure: Keep using this medicine even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medicine for the rest of your life.

If you are taking timolol to prevent migraine headaches: It may take 6 to 8 weeks of daily use before timolol is fully effective. Keep using the medication as directed and tell your doctor if you still have migraine headaches.

Store at room temperature away from moisture, heat, and light.

Timolol dosing information

Usual Adult Dose for Hypertension:

Initial dose: 10 mg orally twice a day
Maintenance dose: 10 to 20 mg orally twice a day
Maximum dose: 30 mg orally twice a day

-There should be an interval of at least 7 days between increases in dosages.
-This drug may be used with a thiazide diuretic or with other antihypertensive agents.

Use: For hypertension alone or in combination with other antihypertensive agents, especially thiazide-type diuretics

Usual Adult Dose for Myocardial Infarction:

Initial dose: 10 mg orally twice a day

Use: For patients who have survived the acute phase of myocardial infarction, and are clinically stable, to reduce cardiovascular mortality and the risk of reinfarction

Usual Adult Dose for Migraine Prophylaxis:

Initial dose: 10 mg orally twice a day
Maintenance dose: 10 to 30 mg given in 1 to 2 divided doses

Use: For the prophylaxis of migraine headache

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking timolol?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect timolol?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may affect timolol, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.