Carbachol

Description

Unlike acetylcholine and methacholine, carbachol contains a carbamino functional group instead of an acetyl group, which is not responsive to hydrolysis by cholinesterase. In vitro studies have shown that the rate of hydrolysis is at least twice as slow as that of acetylcholine.

Chemical properties

white crystalline powder

Chemical properties

Carbachol chloride is a crystalline odorless powder which, on standing in an open container, develops a faint odor resembling that of an aliphatic amine.

Originator

Miostat,Alcon,US,1979

The Uses of Carbachol

Carbachol is a cholinergic agonist and is used for the treatment of glaucoma. It is also used as ophthalmic solution (eye drops) during ophthalmic surgery.

The Uses of Carbachol

Carbamylcholine Chloride is a cholinergic receptor agonist. Studies show that Carbamylcholine Chloride is resistant to the action of cholinesterases. Carbamylcholine Chloride also displays antiapoptotic effects in cerebellar granule neurons.

The Uses of Carbachol

cholinergic, miotic

The Uses of Carbachol

Carbachol is a powerful cholinic ester that stimulates both muscarinic and nicotinic receptors, as well as exhibits all of the pharmacological properties of acetylcholine while in addition resulting in vasodilation, a decrease in heart rate, an increase in tone and contractability of smooth muscle, stimulation of salivary, ocular, and sweat glands as well as autonomic ganglia and skeletal muscle. For this reason, use of carbachol, like acetylcholine, is limited. The exception is that it is used in ophthalmological practice and postoperational intestines and bladder atony. Upon administration in the eye, the pupil constricts and the intraocular pressure is reduced. It is used for severe chronic glaucoma.

What are the applications of Application

Carbachol is an inhibitor of TNF-α and of neuronal apoptosis

Definition

An acetylcholine counterfit molecule that is not inactivated by acetylcholinesterase and is a slowly hydrolyzed cholinergic agonist that acts at both muscarinic and nicotinic receptors.

Manufacturing Process

About 14 g of choline chloride are stirred with a solution of about 20 g of phosgene in 100 g of chloroform for about two hours at room temperature. The mixture becomes a two-phase liquid mixture. Hydrochloric acid and excess phosgene are removed by distillation in vacuo. Chloroform is added to the syrup, and the mixture is then added to a solution of excess ammonia in chloroform which was cooled with solid carbon dioxide-acetone. The mixture is filtered, and the solid is extracted with hot absolute alcohol. The solid in the alcoholic solution is precipitated with ether, and filtered. It is recrystallized from a methyl alcohol-ether mixture; the carbaminoyl-choline chloride obtained has a melting point of about 208°-210°C.

brand name

Carbastat (Novartis); Miostat (Alcon).

Therapeutic Function

Cholinergic

General Description

Prismatic crystals or powder. Odorless, but develops a faint odor of aliphatic amine upon standing in an open container. Cholinergic, parasympathomimetic, used chiefly in large animals, especially for colic in the horse.

General Description

Carbachol forms a carbamylester in the active site of AChE, which is hydrolyzedmore slowly than an acetyl ester. This slower hydrolysis ratereduces the amount of free enzyme and prolongs the durationof ACh in the synapse. Carbachol also stimulates theautonomic ganglia and causes contraction of skeletal musclebut differs from a true muscarinic agent in that it does nothave cardiovascular activity despite the fact that it seems toaffect M2 receptors.

Air & Water Reactions

Hygroscopic.

Reactivity Profile

Carbachol is a carbamate ester. Carbamates are chemically similar to, but more reactive than amides. Like amides they form polymers such as polyurethane resins. Carbamates are incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrides. Flammable gaseous hydrogen is produced by the combination of active metals or nitrides with carbamates. Strongly oxidizing acids, peroxides, and hydroperoxides are incompatible with carbamates.

Hazard

Deadly poison; may cause lowered blood pressure, venous dilation, nausea or vomiting, sweating and lachrymation; a parasympathetic nerve stimulant.

Health Hazard

Highly toxic by mouth.

Fire Hazard

When heated to decomposition, Carbachol emits very toxic fumes of chloride and nitrogen oxides. The aqueous solution is stable even when heated.

Biological Activity

Cholinergic receptor agonist that is resistant to the action of cholinesterases. Blocks apoptosis in cerebellar granule neurons.

Biochem/physiol Actions

Non-selective cholinergic agonist that is resistant to the action of cholinesterases; inhibits apoptotic death of cultured neurons, and may induce apoptosis in thymocytes.

Clinical Use

Carbachol is a miotic and has been used to reduce the intraoculartension of glaucoma when a response cannot beobtained with pilocarpine or neostigmine. Penetration of thecornea is poor but can be enhanced by the use of a wettingagent in the ophthalmic solution. In addition to its topicaluse for glaucoma, carbachol is used during ocular surgery,when a more prolonged miosis is required than can be obtainedwith ACh chloride.

Synthesis

Carbachol, 2-carbamoyloxy-N,N,N-trimethylethyl ammonium chloride (13.1.7), is made by reacting 2-chloroethanol with phosgene, which forms 2-chloroethyl chloroformate (13.1.5). Upon reaction with ammonia, it turns into the corresponding amide (13.1.6), which is further reacted with an equimolar quantity of trimethylamine, giving carbachol (13.1.7) [9¨C13].

Potential Exposure

Used in veterinary medicine as a cholinergic; parasympathomimetic, used chiefly in large animals, especially for colic in the horse

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.

storage

Desiccate at RT

Shipping

UN3249 Medicine, solid, toxic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials. UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1- Poisonous materials, Technical Name Required.

Incompatibilities

Carbachol chloride is a carbamate ester. Esters are generally incompatible with nitrates. Moisture may cause hydrolysis or other forms of decomposition. Carbamates are incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrideds and active metals. Contact with active metals or nitrides form flammable gaseous hydrogen. Incompatible with strongly oxidizing acids, peroxides, and hydroperoxides.

Waste Disposal

It is inappropriate and possibly dangerous to the environment to dispose of expired or waste pharmaceuticals by flushing them down the toilet or discarding them to the trash. Household quantities of expired or waste pharmaceuticals may be mixed with wet cat litter or coffee grounds, double-bagged in plastic, discard in trash. Larger quantities shall carefully take into consideration applicable DEA, EPA, and FDA regulations. If possible return the pharmaceutical to the manufacturer for proper disposal being careful to properly label and securely package the material. Alternatively, the waste pharmaceutical shall be labeled, securely packaged, and transported by a state licensed medical waste contractor to dispose by burial in a licensed hazardous or toxic waste landfill or incinerator.