Pilocarpine

Pilocarpine In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Direct-acting parasympathomimetic that stimulates cholinergic receptors.
• It lowers intraocular pressure by causing ciliary body muscle contraction, miosis and improved aqueous humour outflow.

Uses of Pilocarpine

• Pilocarpine, once employed in glaucoma treatment, has been overshadowed by other topical drugs like carbonic anhydrase inhibitors and prostaglandin analogues.
• It induces pupil constriction (miosis) within 10–15 minutes, persisting for 6–8 hours in dogs.
• Oral pilocarpine boosts tear production and proves beneficial for neurogenic keratoconjunctivitis (dry eye) in dogs.
• Additionally, topical ophthalmic pilocarpine can be utilized, albeit with a potential for irritation.
• Pilocarpine is rarely used for ophthalmic purposes in cats because of potential toxicity.

Dose of Pilocarpine in Dogs and Cats

Dogs:

• Open-angle glaucoma: 1 drop per eye of 1% solution q8–12h.
• Neurogenic KCS: 1 drop of 1–2% solution per 10 kg p.o. q12h (with food) as the initial dose.
• The dose is increased by 1 drop q2–3days until Schirmer tear test (STT) values improve or signs of systemic toxicity are observed (see Adverse Reactions) and then lowered to the previously tolerated dose.

Cats:

• No information is available.

Side Effects of Pilocarpine in Dogs and Cats

• Conjunctival hyperaemia (vasodilation) and local irritation (due to low pH).
• Signs of systemic toxicity include salivation, lacrimation, urinary incontinence, gastrointestinal disturbances, and cardiac arrhythmias.

Contraindications of Pilocarpine in Dogs and Cats

• Avoid in uveitis and anterior lens luxation.

Some Notes: