Ophthalmic glaucoma drops

What is this medication for?

• Primary glaucoma (latanoprost = biggest single-agent IOP reduction) + contralateral-eye prophylaxis (timolol/dorzolamide); secondary glaucomas (dorzolamide — no pupil effect)
• Secondary glaucoma (dorzolamide); latanoprost ineffective/contraindicated (Studer)

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Latanoprost: profound miosis, conjunctival hyperemia, irritation, anterior uveitis risk (Expected/possible)
• Dorzolamide stinging (low pH) (Application pain)
• Timolol: systemic β-blockade (unusually slow heart rate/breathing difficulty/airway tightening — feline asthma caution) (Drop-absorption systemic effect)
• Brimonidine: local allergy, dry mouth (human) (Occasional)

Worth a phone call to your veterinarian

• Any new symptom that worries you.

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Latanoprost: iris darkening (irreversible melanocyte stimulation — human) (Cosmetic-permanent)

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Latanoprost in cats (ineffective) and horses (painful, ineffective); timolol in asthmatic cats (relative)
• has or has had: Miotic agents (latanoprost) contraindicated-adjacent in anterior lens luxation/uveitis glaucoma variants — pupil constriction worsens pupillary-block scenarios per ophthalmology practice

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Deliberate combos
  • Systemic β-blockers + timolol drops

Storage and handling

Latanoprost: refrigerate until opened, then room-temperature ≤6 weeks; others room temperature.

Good to know

• Power ranking in dogs: latanoprost > dorzolamide > timolol for IOP reduction — and combos beat singles (the Cosopt + latanoprost stacking pattern).
• Timolol's honest job: contralateral-eye prophylaxis after one eye lost to primary glaucoma (3–10 mmHg isn't rescue therapy).
• Latanoprost BID in dogs (not human QD) — the canine uveal tract burns through it in 12–15 h.
• Species sanity-check: what works in dogs (latanoprost) fails in cats AND hurts horses — glaucoma pharmacology is species-particular.