Drug information of Dorzolamide and timolol

Dorzolamide and timolol

Drug group:

Dorzolamide ophthalmic reduces the amount of fluid in the eye, which decreases pressure inside the eye.

Timolol ophthalmic is a beta-blocker that also reduces pressure inside the eye.

Dorzolamide and timolol ophthalmic (for the eyes) is a combination medicine used to treat certain types of glaucoma and other causes of high pressure inside the eye

Mechanism of effect

Dorzolamide: Inhibits carbonic anhydrase in the ciliary processes of the eye resulting decreased bicarbonate ion formation which decreases sodium and fluid transport, thus decreasing aqueous humor secretion and reduces intraocular pressure.

Timolol: Blocks both beta1- and beta2-adrenergic receptors, reduces intraocular pressure by reducing aqueous humor production or possibly increases the outflow of aqueous humor

Drug indications

Elevated intraocular pressure: Reduction of elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension who are insufficiently responsive to beta-blockers


Usual Adult Dose for Intraocular Hypertension
 drop in the affected eye(s) 2 times per day
Usual Adult Dose for Glaucoma (Open Angle
 drop in the affected eye(s) 2 times per day
Usual Pediatric Dose for Intraocular Hypertension
 years or older
drop in the affected eye(s) 2 times per day
Usual Pediatric Dose for Glaucoma (Open Angle

years or older
 drop in the affected eye(s) 2 times per day

Drug contraindications

Safety and efficacy have not been established in patients younger than 2 years

Hypersensitivity to dorzolamide, timolol, or any component of the formulation; bronchial asthma or a history of bronchial asthma; severe chronic obstructive pulmonary disease; sinus bradycardia; second- or third-degree atrioventricular block; overt cardiac failure; cardiogenic shock

Side effects

Frequency not always defined. Percentages as reported with combination product. Also see individual agents.
Gastrointestinal: Dysgeusia
Ophthalmic: Burning sensation of eyes, stinging of eyes, blurred vision, conjunctival hyperemia, eye pruritus, superficial punctate keratitis
 to 5%
Cardiovascular: Hypertension
Central nervous system: Dizziness, headache
Dermatologic: Erythema of eyelid
Gastrointestinal: Abdominal pain, dyspepsia, nausea
Genitourinary: Urinary tract infection
Infection: Influenza
Local: Local discoloration (lens nucleus)
Neuromuscular & skeletal: Back pain
Ophthalmic: Blepharitis, cataract (including post-subcapsular), cloudy vision, conjunctival discharge, conjunctival edema, conjunctivitis, corneal erosion, corneal staining, dry eye syndrome, eye discharge (including eyelid), eye disease (debris in eye), eye pain (includes eyelid), eyelid edema, follicular conjunctivitis, foreign body sensation of eye, lacrimation, ocular exudate (eyelid), optic disk cupping (glaucomatous), scaling of eyelid, visual field defect, vitreous detachment
Respiratory: Bronchitis, cough, pharyngitis, sinusitis, upper respiratory tract infection
, postmarketing, and/or case reports: Bradycardia, cardiac failure, cerebrovascular accident, chest pain, choroidal detachment (following filtration procedures), depression, diarrhea, dyspnea, heart block, hypotension, iridocyclitis, myocardial infarction, nasal congestion, paresthesia, photophobia, respiratory failure, skin rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, urolithiasis, vomiting, xerostomia

Acetylcholinesterase Inhibitors, Ajmaline, Alpha-/Beta-Agonists (Indirect-Acting), Alpha1-Blockers, Alpha2-Agonists, Amantadine, Aminoquinolines (Antimalarial), Amiodarone,
Antipsychotic Agents (Phenothiazines), Barbiturates, Beta2-Agonists, Bradycardia-Causing Agents, Bupivacaine, Calcium Channel Blockers (Nondihydropyridine), Carbonic Anhydrase Inhibitors, Cardiac Glycosides, Ceritinib, Cholinergic Agonists, Cobicistat, CYP2D6 Inhibitors (Strong), Dipyridamole, Disopyramide, Dronedarone, EPINEPHrine (Nasal), EPINEPHrine (Oral Inhalation), Epinephrine (Racemic), EPINEPHrine (Systemic), Ergot Derivatives, Fexinidazole [INT], Fingolimod, Floctafenine, Grass Pollen Allergen Extract (5 Grass Extract), Insulins,
Ivabradine, Lacosamide, Lidocaine (Systemic), Lidocaine (Topical), Lumefantrine, Mepivacaine,
Methacholine, Methoxyflurane, Midodrine, NIFEdipine, Nonsteroidal Anti-Inflammatory Agents, Peginterferon Alfa-2b, Propafenone, Regorafenib, Reserpine, Rifamycin Derivatives,
Rivastigmine, Ruxolitinib, Siponimod, Sulfonylureas, Terlipressin, Theophylline Derivatives,


You should not use this medication if you have a history of asthma, chronic obstructive pulmonary disease (COPD), or a serious heart condition such as "AV block," slow heartbeats, heart failure, or if you have recently had a heart attack

Do not use this medicine in a child younger than 2 years old

Dorzolamide and timolol ophthalmic can cause blurred vision. Be careful if you drive or do anything that requires you to be able to see clearly

Dorzolamide is a sulfonamide; although administered ocularly, systemic absorption may occur and could result in hypersensitivity. Discontinue use if signs of hypersensitivity or a serious reaction occur

Systemic absorption and adverse effects (similar to sulfonamides) including blood dyscrasias, Stevens-Johnson syndrome, toxic epidermal necrolysis, and fulminant hepatic necrosis may occur with ophthalmic use

Points of recommendation

You should not use this medication if you are allergic to dorzolamide (Cosopt or Trusopt) or timolol (Blocadren, Betimol, Istalol, Timoptic), or if you have:
a history of asthma
chronic obstructive pulmonary disease (COPD)
a serious heart condition such as "AV block," slow heartbeats, heart failure, or if you have recently had a heart attack

To make sure dorzolamide and timolol ophthalmic is safe for you, tell your doctor if you have:
narrow-angle glaucoma
breathing problems such as bronchitis or emphysema
a history of heart disease or congestive heart failure
a muscle disorder such as myasthenia gravis
kidney disease
liver disease
a thyroid disorder

Do not use this medication while you are wearing contact lenses. This medication may contain a preservative that can be absorbed by soft contact lenses. Wait at least 15 minutes after using the eye drops before putting your contact lenses in

Do not use the eye drops if the liquid has changed colors or has particles in it. Call your pharmacist for new medicine

Tell your doctor right away if you have any eye injury or infection, or if you need to have any type of surgery, especially eye surgery. You may need to stop using dorzolamide and timolol ophthalmic for a short time

Store at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use

Pregnancy level


FDA pregnancy category C. It is not known whether dorzolamide and timolol ophthalmic will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication

Breast feeding warning

It is not known whether dorzolamide and timolol ophthalmic passes into breast milk or if it could harm a nursing baby. You should not breast-feed while you are using dorzolamide and timolol ophthalmic.

Drug forms

Cosopt, Cosopt PF

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