Drug General Information (ID: DDIW0YJ6PU)
Drug Name			Biperiden		Drug Info		Amantadine		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiparkinson Agents				Antiviral Agents
Structure

Mechanism of Biperiden-Amantadine Interaction (Severity Level: Moderate)
Additive anticholinergic effects Click to Show/Hide Mechanism Graph
Drug Name		Biperiden				Amantadine
Mechanism		Parasympatholytic effects				Parasympatholytic effects
Key Mechanism Factor 1
		Factor Name		Anticholinergic effects
		Factor Description		Anticholinergics are medications that block the action of the neurotransmitter acetylcholine. Excessive parasympatholytic effects may result in paralytic ileus, hyperthermia, heat stroke, and the anticholinergic intoxication syndrome.
Mechanism Description		Additive anticholinergic effects by the combination of Biperiden and Amantadine

Recommended Action
Management		Caution is advised when amantadine is used in combination with anticholinergic agents, particularly in the elderly and those with underlying organic brain disease, who tend to be more sensitive to the central anticholinergic effects of these drugs and in whom toxicity symptoms may be easily overlooked. Patients should be advised to notify their physician promptly if they experience potential symptoms of anticholinergic intoxication such as abdominal pain, fever, heat intolerance, blurred vision, confusion, and/or hallucinations. Ambulatory patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them. A reduction in anticholinergic and/or amantadine dosage may be necessary if excessive adverse effects develop.

References
1	Postma JU, van Tilburg W "Visual hallucinations and delirium during treatment with amantadine (Symmetrel)." J Am Geriatr Soc 23 (1975): 212-5. [PMID: 123540]
2	Product Information. Symmetrel (amantadine). DuPont Pharmaceuticals, Wilmington, DE.