Carbachol
Class: Miotics
ATC Class: S01EB02
VA Class: OP102
CAS Number: 51-83-2
Brands: Miostat, Isopto Carbachol
Introduction
Miotic; direct-acting parasympathomimetic agent.
Uses for Carbachol
Open-Angle Glaucoma
Reduction of elevated intraocular pressure (IOP) in patients with primary, open-angle (chronic simple, noncongestive) glaucoma.
Used mainly in patients refractory or hypersensitive to pilocarpine.
May use concomitantly with sympathomimetic agents, β-adrenergic blocking agents, or carbonic anhydrase inhibitors.
Ocular Surgery
Production of miosis during surgery on the anterior chamber of the eye (e.g., cataract extraction, keratoplasty, peripheral iridectomy, cyclodialysis).
Reduction of the intensity of IOP elevation for the first 24 hours after cataract surgery.
Intraocular acetylcholine generally preferred.
Angle-Closure Glaucoma
Reduction of IOP in the emergency treatment of acute (congestive) angle-closure glaucoma† prior to surgery.
Pilocarpine generally preferred.
Ophthalmologic Examinations
Production of miosis to counteract mydriatic effects of sympathomimetic agents (e.g., hydroxyamphetamine, phenylephrine) after ophthalmoscopic examinations† in glaucoma patients.
Pilocarpine generally preferred.
Carbachol Dosage and Administration
Administration
Ophthalmic Administration
Administer ophthalmic topical solution to the conjunctival sac; do not inject.
Administer intraocular injection by injection into the anterior chamber.
Topical Solution
Remove contact lenses before instilling solution.
To minimize adverse effects, begin with a low concentration and increase gradually as needed. Additionally, instill daily dose or one of the daily doses at bedtime.
Following topical instillation, apply finger pressure on the lacrimal sac for 1–2 minutes to minimize drainage into nose and throat and reduce risk of absorption and systemic reactions. Remove excess solution around the eye with a tissue and rinse off any medication on hands immediately.
Intraocular Injection
Instill into anterior chamber of the eye before or after securing sutures, following the manufacturer’s directions. Vials are for single-dose use only; discard unused portion.
Dosage
Adjust concentration and frequency of solution instillation according to patient requirements and response, as determined by tonometric readings before and during therapy.
In patients with heavily pigmented irides, higher solution concentrations may be required.
Adults
Open-Angle Glaucoma
Ophthalmic Topical
1–2 drops of 1.5–3% topical solution up to 3 times daily.
Ocular Surgery
Intraocular
Inject ≤0.5 mL of a 0.01% solution.
Prescribing Limits
Adults
Ocular Surgery
Intraocular
Maximum: 0.5 mL of a 0.01% injection.
Special Populations
No special population dosage recommendations at this time.
