Carbachol
Is a cholinomimetic drug that binds and activates the acetylcholine receptor.
Classified as a cholinergic agonist.
Primarily used for various ophthalmic purposes, such as for treating glaucoma, or for use during ophthalmic surgery.
Generally administered as an ophthalmic solution.
Trade name Miostat.
Pregnancy category US: C. -Risk not ruled out.
Routes of administration-Topical ophthalmic solution.
Bioavailability is Low.
It is not well absorbed in the gastro-intestinal tract and does not cross the blood–brain barrier.
It is administered topical ophthalmic or through intraocular injection.
Carbachol is not easily metabolized by cholinesterase, and is poorly absorbed through topical administration, so benzalkonium chloride is mixed in to promote absorption.
It has a 2 to 5 minute onset of action and its duration of action is 4 to 8 hours with topical administration and 24 hours for intraocular administration.
A parasympathomimetic agent that stimulates both muscarinic and nicotinic receptors.
Its main effects are miosis and increased aqueous humour outflow.
Primarily used in the treatment of glaucoma, but it is also used during cataract surgery to constrict the pupils.
Topical ocular administration is used to decrease intraocular pressure in people with primary open-angle glaucoma.
Intraocular administration is used to produce miosis after lens implantation during cataract surgery.
Carbachol can also be used to stimulate bladder emptying if the normal emptying mechanism is not working properly, when indicated for urinary retention it is used as an oral (2 mg) tablet.
Use is contraindicated in patients with asthma, coronary insufficiency, gastroduodenal ulcers, and incontinence, as the parasympathomimetic action of this drug will exacerbate the symptoms of these disorders.
When administered ocularly there is little risk of side effects