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Timolol

Prescription
Beta-adrenergic blocker (ophthalmic)
Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
3 available
Formulations
2

Mechanism of action

Non-selective beta-blocker that reduces aqueous humor production by the ciliary body, lowering intraocular pressure

At a glance

Class
Beta-adrenergic blocker (ophthalmic)
Schedule
Prescription
Storage
Store below 25°C, protect from light; discard 28 days after opening

Dosing

🐕

Dog

Glaucoma (adjunct to primary therapy)
Dose
0 mg/kg
Route
Ophthalmic
Frequency
BID
Max dose
0 mg
Duration: Long-term as adjunct; 1 drop per affected eye
🐈

Cat

Glaucoma (adjunct)
Dose
0 mg/kg
Route
Ophthalmic
Frequency
BID
Max dose
0 mg
Duration: Long-term; 1 drop per affected eye
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

🧴

Ophthalmic solution — 2

Strength
0.25%
Available in India
Strength
0.5%
Available in India

Storage

Store below 25°C, protect from light; discard 28 days after opening

Safety

Absolute contraindications — do not use

  • Asthma / Bronchospasm
    Systemic absorption can worsen bronchoconstriction

Use with caution

  • Bradycardia or heart block
    Systemic beta-blockade from ophthalmic absorption
  • Brachycephalic breeds
    Higher respiratory sensitivity

Adverse effects

Common
Mild ocular stinging
Slight decrease in heart rate
Serious
Bradycardia
Bronchospasm (systemic absorption)

Monitoring parameters

Intraocular pressureHeart rateRespiratory rate
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Interactions

No documented interactions.

Brands

International

Timoptic
Merck

India

Iotim
FDC Limited
Glucomol
Allergan India

FAQs

Frequently asked questions

What is Timolol?
Timolol is a beta-adrenergic blocker (ophthalmic) used in pets. Non-selective beta-blocker that reduces aqueous humor production by the ciliary body, lowering intraocular pressure
What is Timolol used for in pets?
Timolol is used in veterinary medicine for: Glaucoma (adjunct to primary therapy); Glaucoma (adjunct).
What is the Timolol dose for dogs?
For dogs, Timolol is typically dosed as follows — Glaucoma (adjunct to primary therapy): 0 mg/kg Ophthalmic BID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the Timolol dose for cats?
For cats, Timolol is typically dosed as follows — Glaucoma (adjunct): 0 mg/kg Ophthalmic BID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What are the side effects of Timolol?
Common: Mild ocular stinging, Slight decrease in heart rate. Serious (call your vet immediately): Bradycardia, Bronchospasm (systemic absorption).
Does Timolol need a prescription?
Yes. Timolol is a prescription medication and should only be administered under veterinary supervision.
When should Timolol not be used?
Do not use Timolol if: Asthma / Bronchospasm.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

References

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

  • Plumb's Veterinary Drug Handbook
  • Withrow & MacEwen's Small Animal Clinical Oncology
  • Merck Veterinary Manual
  • NRC Nutrient Requirements of Dogs and Cats
  • Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

  • ASPCA Animal Poison Control Center Guidelines
  • AAHA Diabetes Management Guidelines
  • ASPCA Poison Control Guidelines
  • RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

  • EPIC Study (J Vet Intern Med 2016)
  • JVIM FAT CAT Study

Regulatory & approvals — 1

  • CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

  • Washington State University VCPL MDR1 Database
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