Antiparkinsonism-anticholinergic drugs

Amantadine is less effective than levodopa in the treatment of Fhrkinson s disease but more effective than die anticholinergics. Amantadine may be given alone or in combination witii an antiparkinsonism drug witii anticholinergic activity. Amantadine is also used as an antiviral drug (see Chap. 14). 

Frequently seen adverse reactions to dragp with anticholinergic activity include dry mouth, blurred vision, dizziness, mild nausea, and nervousness. These may become less pronounced as therapy progresses. Other adverse reactions may include skin rash, urticaria (hives), urinary retention, dysuria, tachycardia, muscle weakness, disorientation, and confusion. If any of these reactions are severe, the drug may be discontinued for several days and restarted at a lower dosage, or a different antiparkinsonism drag may be prescribed. 

Prescription and nonprescription anticholinergics Antiparkinson drugs Trihexyphenidyl (Artane)... 

Drugs that may interact with anticholinergic antiparkinson agents include... 

Opioids, antiepileptics, levodopa, antiparkinsonism drugs, psychotropic drugs, anticholinergics Corticosteroids, diuretics... 

McEvoy, J. (1987). A double-blind crossover comparison of antiparkinsonism drug therapy Amantadine versus anticholinergics in 90 normal volunteers, with an emphasis on differential effects on memory function. Journal of Clinical Psychiatry, 48, 20-23. 

The side effects of these drugs are well known and have been summarized earlier (SED VIII, p. 313). Drugs with selective activity may be classified as antidepressants, antipsychotics, antihistamines, antispasmod-ics or antiparkinsonism agents and yet have anticholinergic actions as side effects. When two or more are given together the unwanted effects are more likely to arise. 

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