Non-selective beta-blocker that reduces aqueous humor production by the ciliary body, lowering intraocular pressure
At a glance
Class
Beta-adrenergic blocker (ophthalmic)
Storage
Store below 25°C, protect from light; discard 28 days after opening
Dosing
Glaucoma (adjunct to primary therapy)
Duration: Long-term as adjunct; 1 drop per affected eye
Glaucoma (adjunct)
Duration: Long-term; 1 drop per affected eye
Safety
Absolute contraindications — do not use
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)
Intraocular pressureHeart rateRespiratory rate
Interactions
No documented interactions.
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.
References
References
Textbooks & handbooks
- Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
- Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
- Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
- National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
- The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/
Clinical guidelines & consensus
- Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
- American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.
Journals & peer-reviewed studies
- Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
- Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
- ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control
Regulatory & approvals
- Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/
Databases
- Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
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.
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