Dorzolamide-Timolol Maleate

What Is Dorzolamide-Timolol Maleate?

Dorzolamide-timolol maleate is a prescription eye drop that combines two medicines in one bottle:

• Dorzolamide hydrochloride, a carbonic anhydrase inhibitor
• Timolol maleate, a beta-adrenergic blocker (beta-blocker)

It is used only in the eye. It is not taken by mouth or injected.

Approved use

• Lowering eye pressure (intraocular pressure) in people with open-angle glaucoma or ocular hypertension who need more than one medicine to reach their target pressure.

Available formulations and strengths

• Ophthalmic solution: dorzolamide 2% / timolol 0.5%, a fixed-dose combination
• Multi-dose bottles (which contain a preservative) and preservative-free single-use or multi-dose preservative-free versions in some countries
• Available as brand-name and generic products. Availability and labeling vary by country.

This is different from other combination eye drops, such as brimonidine-timolol, which contain a different second ingredient. Each strength has its own detailed page.

What Is the Recommended Dosage of Dorzolamide-Timolol Maleate?

Dosing depends on several factors:

• Condition: The product is used for glaucoma or high eye pressure, as directed by an eye specialist.
• Age: Safety and effectiveness in children have not been fully established in all regions. Use in children should only be directed by a pediatric eye specialist.
• Body weight: Weight is generally not used to set the dose of eye drops.
• Organ function: People with kidney or liver problems may need closer monitoring, because both ingredients can be absorbed into the body and processed by these organs. Use is not recommended in people with severe kidney impairment.
• Other medicines: Some medicines can raise the amount of timolol absorbed in the body.

Dosage form: Eye drop solution in a multi-dose bottle or preservative-free container.

The prescriber decides how many drops to use, in which eye or eyes, and how often. Always follow the prescription and the label. Using extra drops does not improve results and may increase side effects. Do not change your schedule without speaking with your specialist.

How Dorzolamide-Timolol Maleate Works

Each ingredient lowers eye pressure by reducing the amount of fluid the eye produces, using different pathways:

• Dorzolamide blocks an enzyme called carbonic anhydrase, which helps the eye make fluid.
• Timolol blocks beta receptors in the eye, which also reduces fluid production.

Using two medicines with different actions can lower eye pressure more than one alone for some people. Lower eye pressure helps protect the optic nerve from damage.

Dorzolamide-timolol manages glaucoma but does not cure it. Glaucoma is a long-term condition. Eye pressure may rise again if treatment is stopped, and lost vision cannot be restored.

Is a Prescription Required to Buy Dorzolamide-Timolol Maleate Online?

Yes. Dorzolamide-timolol maleate is prescription-only. A licensed ophthalmologist (or another licensed eye care professional) must evaluate you and diagnose your condition first.

Safety when buying online

• Buy only from licensed, verified pharmacies that require a valid prescription.
• Avoid websites that sell prescription eye medicines without a prescription.
• Counterfeit, expired, or improperly stored eye drops can cause eye infection or vision harm. Do not use veterinary products.
• Check the packaging, label, and seal when it arrives. Ask a pharmacist if anything looks unusual.

Side Effects of Dorzolamide-Timolol Maleate

Common Side Effects

• Eye burning, stinging, or discomfort right after using the drops
• A bitter or unusual taste in the mouth after use
• Eye redness, itching, or tearing
• Blurred vision
• Dry eyes or a feeling that something is in the eye
• Headache
• Inflammation or irritation of the eyelids or the surface of the eye

Serious Side Effects

These are uncommon but need prompt attention.

• Signs of a severe allergic reaction: swelling of the face, lips, tongue, or throat; hives; trouble breathing
• Severe skin reactions: widespread rash, blistering, or peeling skin (dorzolamide is a sulfonamide)
• Breathing problems, such as wheezing, shortness of breath, or worsening asthma or COPD symptoms (timolol can be absorbed into the body)
• Very slow or irregular heartbeat, fainting, severe dizziness, or very low blood pressure
• Signs of heart failure: swelling of the ankles, sudden weight gain, or new shortness of breath
• Kidney stones: severe pain in the side or back, or blood in the urine
• Eye pain, sudden vision changes, swelling or cloudiness of the cornea, or signs of eye infection
• Muscle weakness that is new or worsening

Seek emergency medical care for trouble breathing, swelling of the face or throat, widespread skin blistering or peeling, fainting, or chest pain. Contact your specialist promptly if side effects are bothersome or do not go away.

Drug Interactions

Dorzolamide-timolol maleate may interact with:

• Oral carbonic anhydrase inhibitors, such as acetazolamide, which may add to side effects and acid-base effects
• Blood pressure medicines, including other beta-blockers and calcium channel blockers, which may cause very low blood pressure or a slow heart rate
• Heart rhythm medicines, such as digoxin, amiodarone, and quinidine
• CYP2D6-inhibiting medicines, such as certain antidepressants (for example, fluoxetine and paroxetine) and quinidine, which can increase the amount of timolol in the body
• Catecholamine-depleting medicines, such as reserpine
• Clonidine: stopping clonidine while using a beta-blocker may cause a sharp rise in blood pressure
• High-dose aspirin and other salicylates, which may build up in the body when combined with carbonic anhydrase inhibitors
• Diabetes medicines, including insulin: timolol may hide some warning signs of low blood sugar
• Epinephrine: beta-blockers may make allergic reactions harder to treat
• Other eye drops: wait at least 10 minutes between different eye medicines

OTC medicines, supplements, and herbal products, including cold and allergy remedies, aspirin-containing pain relievers, and decongestants, may also interact. Give your licensed specialist and pharmacist a full list of everything you take, including eye drops, creams, vitamins, and supplements.

Safety & Important Considerations

• Asthma and lung disease: Timolol can cause serious breathing problems in people with asthma or COPD, even as an eye drop.
• Heart conditions: Use caution with heart failure, slow heart rate, heart block, low blood pressure, or circulation problems such as Raynaud’s phenomenon.
• Sulfa allergy: Tell your specialist if you have ever had a reaction to sulfonamide (sulfa) medicines.
• Diabetes: Timolol may hide symptoms of low blood sugar, such as a fast heartbeat.
• Thyroid disease: Timolol may hide signs of an overactive thyroid.
• Muscle weakness conditions: Tell your specialist if you have myasthenia gravis or similar conditions.
• Liver or kidney disease: Tell your specialist. Use is not recommended with severe kidney impairment, and kidney stone history should also be shared.
• Corneal health: Dorzolamide may cause swelling of the cornea in people with existing corneal problems. Your specialist may monitor this.
• Pregnancy and breastfeeding: Human data are limited. Timolol can pass into breast milk. Discuss risks and benefits with your specialist before use.
• Children: Use only under the direction of a pediatric eye specialist.
• Older adults: May be more sensitive to dizziness, low blood pressure, and slow heart rate.
• Contact lenses: The preservative (benzalkonium chloride) in many eye drops can be absorbed by soft contact lenses. Remove lenses before use and wait at least 15 minutes before reinserting them, unless your label says otherwise.
• Driving and machinery: The medicine may cause dizziness, blurred vision, or tiredness. Avoid these activities until you know how it affects you.
• Surgery: Tell your surgeon or anesthesiologist that you use a beta-blocker eye drop.
• Monitoring: Glaucoma treatment requires regular eye pressure checks and eye exams. Your specialist may also check your heart rate and blood pressure.
• Hygiene: Do not touch the dropper tip to your eye or any surface. This lowers the risk of contamination.

Who This Medication Is For

• Adults diagnosed with open-angle glaucoma or ocular hypertension by an eye specialist
• People whose eye pressure is not controlled enough with a single medicine, as determined by their specialist

Who Should Not Take Dorzolamide-Timolol Maleate

• Anyone allergic to dorzolamide, timolol, sulfonamides, or any ingredient in the product
• People with asthma, a history of asthma, or severe COPD
• People with a very slow heart rate, certain types of heart block, overt heart failure, or cardiogenic shock
• People with severe kidney impairment, unless a specialist advises otherwise

Tell your specialist about all medical conditions before starting treatment.

What to Do If You Miss a Dose

• Use the missed dose as soon as you remember.
• If it is almost time for the next dose, skip the missed one and return to your usual schedule.
• Do not double the dose to make up for a missed one.
• If you are unsure what to do, contact your licensed specialist or pharmacist.

Related medications to Dorzolamide-Timolol Maleate

Only a licensed specialist can decide whether a different treatment suits you.

• Prostaglandin analogs (for example, latanoprost)
• Beta-blockers alone (for example, timolol)
• Carbonic anhydrase inhibitors alone (for example, dorzolamide or brinzolamide)
• Alpha-2 agonists (for example, brimonidine)
• Other combination eye drops, such as brimonidine-timolol or brimonidine-brinzolamide
• Rho kinase inhibitors
• Laser therapy or surgery in some cases

Do not stop or switch treatments on your own. Changes should be made only after consultation with your specialist.

Storage Instructions

• Store at room temperature, typically 59°F to 77°F (15°C to 25°C), unless your label says otherwise.
• Keep the bottle tightly closed and protect it from moisture, heat, and direct light.
• Do not freeze.
• Keep out of reach and sight of children. Accidental swallowing of eye drops can be dangerous for young children. Seek emergency help if this happens.
• Do not use past the expiration date. Many eye drop bottles should be discarded within a set time after opening (often about 4 weeks). Preservative-free single-use containers should be discarded after use. Follow your label and pharmacist’s guidance.

Disclaimer

This page is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Patients must consult a licensed ophthalmologist or another relevant medical specialist before starting, changing, or stopping treatment. Treatment decisions must be based on a full clinical evaluation by a qualified specialist.