Carbachol
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| Brand Name | (company) | [Country] |
| Carbastat | (CIBA Vision) | |
| Carboptic | (?) | [U.S.] |
| Isopto Carbachol | (Alcon) | |
| Miostat | (Alcon) | |
| Generic name (INN): carbachol | ||
| Other names: carbamylcholine | ||
Carbachol (Kar-ba-kol [key]), also known as carbamylcholine, is classified as a cholinergic. It is primarily used in the treatment of glaucoma, but is also used during ophthalmic surgery. In most countries it is only available by prescription. Carbachol eyedrops are used to decrease the pressure in the eye for people with glaucoma. It is sometimes used to constrict the pupils during cataract surgery.
In the cat and rat, carbachol is well-known for its ability to induce rapid eye movement (REM) sleep when microinjected into the pontine reticular formation. Carbachol elicits this REM sleep-like state via activation of postsynaptic muscarinic cholinergic receptors (mAChRs).
| Contents |
Clinical Info
Chemistry and pharmacokinetics
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2-[(Aminocarbonyl)oxy]-N,N,N-trimethylethanaminium chloride | |
| Empiric formula | C6H15N2O2 . Cl |
| Molecular weight | 182.68 |
| SMILE | NC(OCC[N+](C)(C)C)=O |
| Metabolism | |
| Elimination half life | |
| Excretion | |
| Pregnancy category | C (US) |
Carbachol is a choline ester and a positively charged quaternary ammonium compound. It is not well absorbed in the gastro-intestinal tract and does not cross the blood-brain barrier. It is usually administered topical ocular or through intraocular injection. Carbachol is not easily metabolized by cholinesterase, its duration of action is 4 to 8 hours with topical administration and 24 hours for intraocular administration. Since carbachol is poorly absorbed through topical administration, benzalkonium chloride is mixed in to promote absorption.
Mechanisms of action
Carbachol is a parasympathomimetic that stimulates both muscarinic and nicotinic receptors. In topical ocular and intraocular administration its principal effects are miosis and increased aqueous humour outflow.
Indications
Topical occular 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.
Contraindications and precautions
Overdose
Sources
- Brenner, G. M. (2000). Pharmacology. Philadelphia, PA: W.B. Saunders Company. ISBN 0-7216-7757-6
- Canadian Pharmacists Association (2000). Compendium of pharmaceuticals and specialties (25th ed.). Toronto, ON: Webcom. ISBN 0-919115-76-4
- Carbachol (1998). MedlinePlus. Retrieved June 27, 2004, from http://www.nlm.nih.gov/medlineplus/druginfo/uspdi/202110.html
- Carbachol (2003). RxList. Retrieved June 27, 2004, from http://www.rxlist.com/cgi/generic2/carbachol.htm
- National Institute for Occupational Safety and Health. (2002). Choline, chloride, carbamate. In The registry of toxic effects of chemical substances. Retrieved June 27, 2004, from http://www.cdc.gov/niosh/rtecs/gad59f8.html
- Carbachol Chloride (2004). Hazardous Substances Data Bank. Retrieved July 16, 2004, from http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?hsdbb.htm (search carbachol).