Demecarium bromide, trade name Humorsol, is a carbamate

parasympathomimetic A parasympathomimetic drug, sometimes called a cholinomimetic drug or cholinergic receptor stimulating agent, is a substance that stimulates the parasympathetic nervous system (PSNS). These chemicals are also called cholinergic drugs because ace ...

drug that acts as an

acetylcholinesterase inhibitor Acetylcholinesterase inhibitors (AChEIs) also often called cholinesterase inhibitors, inhibit the enzyme acetylcholinesterase from breaking down the neurotransmitter acetylcholine into choline and acetate, thereby increasing both the level and ...

, and is used as a

glaucoma medication Glaucoma medication is divided into groups based on chemical structure and pharmacologic action. The goal of currently available glaucoma therapy is to preserve visual function by lowering intraocular pressure (IOP), below a level that is likely ...

. It is applied directly to the eye in order to reduce elevated

intraocular pressure Intraocular pressure (IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk of glaucoma. Most tonometers are calibrated to ...

associated with

glaucoma Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye rem ...

. Demecarium causes constriction of the pupil (

miosis Miosis, or myosis (), is excessive constriction of the pupil.Farlex medical dictionary
citing: ...

), which improves the drainage of the fluid in the eye (

aqueous humour The aqueous humour is a transparent water-like fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary body, a structure supporting the lens of the eyeball. It fills both the anterior and the posterio ...

). As demecarium reversibly inhibits

cholinesterase The enzyme cholinesterase (EC 3.1.1.8, choline esterase; systematic name acylcholine acylhydrolase) catalyses the hydrolysis of choline-based esters: : an acylcholine + H2O = choline + a carboxylate Several of these serve as neurotransmitters ...

, it can be administered less frequently than other parasympathomimetic drugs, such as

carbachol Carbachol, also known as carbamylcholine and sold under the brand name Miostat among others, is a cholinomimetic drug that binds and activates acetylcholine receptors. Thus it is classified as a cholinergic agonist. It is primarily used for va ...

. Commercially produced demecarium bromide solution, previously sold under the trade name Humorsol, is no longer available, although solutions of demecarium can be compounded.

Use in dogs

When administered with a topical

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involv ...

, demecarium can delay the onset of primary glaucoma in dogs. High doses of demecarium may cause organophosphate toxicity, particularly if flea treatments containing organophosphates are administered at the same time.

References

{{Acetylcholine metabolism and transport modulators Acetylcholinesterase inhibitors Bromides Biscarbamates Ophthalmology drugs Quaternary ammonium compounds Veterinary drugs Bisquaternary anticholinesterases Aromatic carbamates Phenol esters

Use in dogs

See also

References