Anticholinergic Drugs and Amantadine in the Treatment of Parkinson’s Disease

Anticholinergics and amantadine both result in mild to moderate improvement in Parkinson’s disease. These drugs still have an important role to play in the treatment of the disease despite the greater clinical effects of levodopa and dopamine agonists. They may be used either as monotherapy or as adjunctive treatment. Benefit can be obtained in all stages of the disease, but it is typically most noticeable early on when disability is less marked. Many neurologists utilize these drugs initially in hopes of delaying the need for levodopa and later to permit the use of lower doses of this agent because of increasing concern that early treatment with levodopa may create many of the long-term problems faced in the later stages of the disease. In this chapter we will review anticholinergic and amantadine treatment of Parkinson’s disease, emphasizing the proposed mechanisms of action, what is known of the pharmacokinetics, the clinical effectiveness and side effects.