amantadine, Symmetrel (Discontinued) (cont.)

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DOSING: Amantadine is taken once or twice daily with or without food. If it causes an upset stomach, it can be taken with food. The dosage for prevention and treatment of influenza A infections in adults is 200 mg daily. For treatment of influenza, amantadine should be started within 24 to 48 hours after the onset of signs or symptoms and should be continued for 24 to 48 hours after the disappearance of signs or symptoms. To prevent influenza, amantadine should be started as soon as possible after exposure to the influenza virus and continued for at least 10 days. Persons with reduced kidney function and elderly persons may need lower doses (or less frequent doses).

The dosage for treating Parkinson's or extrapyramidal symptoms is 100 mg twice daily.

DRUG INTERACTIONS: Amantadine adds to the sedating effects of alcohol and other sedating drugs such as the benzodiazepine class of anti-anxiety drugs (for example, diazepam [Valium], lorazepam [Ativan], clonazepam [Klonopin], alprazolam [Xanax, Xanax XR, Niravam], zolpidem [Ambien, Ambien CR, Zolpimist, Edluar]), the tricyclic class of antidepressants (for example, amitriptyline [Elavil, Endep], imipramine [Tofranil, Tofranil-PM], desipramine [Norpramin]), dicyclomine (Bentyl), certain antihistamines (diphenhydramine [Benadryl], hydroxyzine [Vistaril, Atarax], clemastine), opiate agonists (for example, Dilaudid, hydrocodone/acetaminophen [Vicodin, Vicodin ES, Lorcet, Lorcet Plus, Norco], oxycodone and acetaminophen [Percocet, Roxicet, Tylox, Oxycet] codeine) and certain antihypertensive medications (for example, clonidine [Catapres, Catapres-TTS, Jenloga], propranolol [Inderal, Inderal LA, Innopran XL]). Such combinations can cause dizziness, confusion, lightheadedness, fainting, or dizziness upon standing (orthostatic hypotension).

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