Demecarium is a parasympathomimetic that acts as an acetylcholinesterase inhibitor. It is one of several topical (applied directly to the affected area) medications used to reduce elevated intraocular pressure (IOP) associated with primary glaucoma in cats, dogs, and other animals. a cholinesterase inhibitor with sustained activity. It acts mainly on true (erythrocyte) cholinesterase. Application of HUMORSOL (demecarium) to the eye produces intense miosis and ciliary muscle contraction due to inhibition of cholinesterase, allowing acetylcholine to accumulate at sites of cholinergic transmission. These effects are accompanied by increased capillary permeability of the ciliary body and iris, increased permeability of the blood-aqueous barrier, and vasodilation. Myopia may be induced or, if present, may be augmented by the increased refractive power of the lens that results from the accommodative effect of the drug. HUMORSOL (demecarium) indirectly produces some of the muscarinic and nicotinic effects of acetylcholine as quantities of the latter accumulate.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.