Detailed Drug Information:
DRUG CLASS AND MECHANISM: Galantamine is an oral medication used to treat patients with Alzheimer's disease. Galantamine is in a class of drugs called cholinesterase inhibitors that also includes tacrine (Cognex), donezepil (Aricept), and rivastigmine (Exelon). Cholinesterase inhibitors inhibit (block) the action of acetylcholinesterase, the enzyme responsible for the destruction of acetylcholine. Acetylcholine is one of several neurotransmitters in the brain, chemicals that nerve cells use to communicate with one another. Reduced levels of acetylcholine in the brain are believed to be responsible for some of the symptoms of Alzheimer's disease. By blocking the enzyme that destroys acetylcholine, galantamine increases the concentration of acetylcholine in the brain, and this increase is believed to be responsible for the improvement in thinking seen with galantamine. Galantamine was approved by the FDA in 2001.
PREPARATIONS: Tablets: 4 mg (white), 8 mg (pink) and 12 mg (orange-brown). Oral solution: 4 mg/mL.
STORAGE: Tablets and liquid solution should be stored at room temperature, 15-30°C (59-86°F).
PRESCRIBED FOR: Galantamine is used for the treatment of mild to moderate dementia of the Alzheimer's type.
DOSING: Galantamine usually is taken twice daily, preferably with the morning and evening meals. Most often, galantamine therapy is started with the lowest dose, 4 mg twice daily, for several weeks, and then continued at 8 mg twice daily for a further several week period. Thereafter, some patients may need a higher dose.
DRUG INTERACTIONS: Drugs with anticholinergic properties and which cross into the brain, such as atropine, benztropine (Cogentin), and trihexyphenidyl (Artane) produce opposite effects of (counteract) galantamine and should be avoided during therapy with galantamine. Unlike donepezil (Aricept), galantamine does not increase blood levels of other medications and increase their risk for side effects.
PREGNANCY: Studies in pregnant rats and rabbits using galantamine at high doses failed to show effects on the offspring; however, no studies have been performed in pregnant women. Therefore, physicians must weigh the potential benefits against the potential risks of galantamine before prescribing it for pregnant women.
NURSING MOTHERS: It is not known if galantamine is secreted in breast milk.
SIDE EFFECTS: The most frequent side effects seen with galantamine are nausea (one in six treated persons), vomiting (up to one in ten persons), diarrhea (up to one in eight persons), anorexia (loss of appetite), and weight loss. These side effects generally occur during the beginning of treatment or when the dose is increased. These side effects typically are mild and temporary. Taking galantamine with food and ensuring adequate fluid intake may reduce the impact of these side effects. Fewer than one in ten persons will need to stop treatment due to side effects.
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