dorzolamide hydrochloride + timolol maleate at a glance
Medicine class
A fixed combination of a carbonic anhydrase inhibitor and a non-selective beta blocker.
Main role
Lowers raised eye pressure when topical beta-blocker treatment alone is insufficient.
Reducing absorption
Closing the eyelid and pressing gently beside the nose for two minutes reduces absorption into the bloodstream.
What is dorzolamide hydrochloride + timolol maleate used for?
Licensed to lower raised intraocular pressure when topical beta-blocker treatment alone is insufficient.
Open-angle glaucoma
Pseudoexfoliative glaucoma
How does dorzolamide hydrochloride + timolol maleate work?
Both ingredients reduce production of aqueous humour, the fluid inside the front of the eye. Dorzolamide inhibits carbonic anhydrase II, while timolol blocks beta receptors. Their complementary actions lower intraocular pressure more than either component alone.
dorzolamide hydrochloride + timolol maleate preparations and strengths
Eye drops
Route: Ophthalmic
Strengths: 20 mg/mL + 5 mg/mL
How to take dorzolamide hydrochloride + timolol maleate
Use exactly as prescribed and follow the container instructions. Food does not affect eye-drop administration.
Wash and dry your hands.
Open a fresh single-use container and check that its tip is undamaged.
Pull down the lower eyelid and apply the medicine without touching the eye, skin or another surface with the tip.
Close the eye and press gently at the inner corner beside the nose for two minutes.
Keep other eye preparations separate as directed by the prescriber or pharmacist.
Discard the opened container and remaining solution immediately after use.
Do not drive or operate machinery until blurred vision clears.
dorzolamide hydrochloride + timolol maleate side effects
Common or expected effects
- Burning or stinging in the eye
- Eye redness, itching or watering
- Temporary blurred vision
- Corneal irritation or erosion
- Unusual or bitter taste
- Sinus symptoms
Get urgent medical advice
- Allergic reaction with swelling, rash or breathing difficulty
- Bronchospasm or severe shortness of breath
- Markedly slow or irregular heartbeat, chest pain, fainting or worsening heart failure
- Severe blistering or peeling skin reactions
- Persistent eye pain, inflammation or worsening vision
dorzolamide hydrochloride + timolol maleate in pregnancy
The selected combination product should not be used during pregnancy according to its UK product information. Evidence for the combination is limited, so pregnancy or plans for pregnancy require prompt review by the eye specialist or prescriber. Do not stop treatment without advice.
dorzolamide hydrochloride + timolol maleate while breastfeeding
Breastfeeding is not recommended when this combination is required because dorzolamide transfer into human milk is unknown. A prescriber should assess treatment needs and feeding options; advice for timolol alone should not automatically be applied to the combination.
dorzolamide hydrochloride + timolol maleate interactions
Systemic interactions remain possible because both ingredients can be absorbed from the eye.
Systemic beta blockers or other beta-blocker eye drops
May increase beta-blocker effects, including a slower heart rate, lower blood pressure or respiratory effects. Two topical beta blockers are not recommended.
Oral carbonic anhydrase inhibitors
May increase systemic carbonic anhydrase inhibition and are not recommended with dorzolamide.
Calcium-channel blockers, digoxin, antiarrhythmics or parasympathomimetics
Additive effects may cause marked bradycardia or hypotension.
Common questions about dorzolamide hydrochloride + timolol maleate
Answers are fully visible for fast scanning and source review.
Why does this treatment contain two ingredients?
They reduce eye-fluid production through different mechanisms, producing a greater pressure-lowering effect than either component alone.
Can it enter the bloodstream?
Yes. Small amounts can be absorbed, so heart, lung and other effects associated with beta blockers or sulfonamides remain possible.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.