Demecarium Bromide for Veterinary Use

Therapeutic Class: Parasympathomimetic, carbamate inhibitor

Species: Dogs

May Be Prescribed For: Glaucoma

Demecarium bromide is a potent, long acting cholinesterase- inhibitor used topically to treat acute glaucoma. Parasympathomimetic drugs cause contraction of the muscles associated with the ciliary body and of the iris sphincter. This allows increased outflow of aqueous humor by mechanically opening the iridocorneal angle. Parasympathomimetic drugs also increase aqueous humor protein and may cause vasodilation of the conjunctiva. In dogs, demecarium bromide has been shown to decrease intraocular pressure for up to 48 hours.

The most commonly used parasympathomimetic to treat primary glaucoma is 2% pilocarpine. Demecarium bromide is an alternative drug.

Acute primary glaucoma generally is a breed-related hereditary condition. It is a true medical emergency. Topical prostaglandins are the first-line drugs of choice in the affected eye. Demecarium bromide often is used in the medical management of the non-affected eye. Almost all cases of primary glaucoma will become bilateral if the contralateral eye is not monitored and appropriately medicated. One of the advantages to demecarium bromide is that it may be administered once or twice a day.

• Local inflammation of the eye. Topical ophthalmic corticosteroids may be used to diminish irritation.

• Systemic side-effects generally are related to GI distress, although cardiac-related symptoms are possible. Particular care should be exercised with small breed dogs or when high doses are used.

• Demecarium bromide should be used with caution with other cholinesterase inhibitors and with succinylcholine.

• Demecarium bromide should not be used during pregnancy.

• Demecarium bromide should not be used in animals with secondary glaucoma due to active anterior uveitis. Under these circumstances, it will both increase the pain and other symptoms.

• Parasympathomimetic drugs may cause a flare up of iritis.

• Sympathomimetic drugs such as dipivefrin also increase the outflow of aqueous humor but by a different mechanism than the parasympathomimetic drugs such as demecarium bromide. These drugs are synergistic and can be used in the same eye, although treatment should be spaced by five or 10 minutes.