A number of centrally acting antimuscarinic preparations are available that differ in their potency and in their efficacy in differ-ent patients. Some of these drugs were discussed. These agents may improve the tremor and rigidity of parkin-sonism but have little effect on bradykinesia. Some of the more commonly used drugs are listed in Table 28–1
Treatment is started with a low dose of one of the drugs in this category, the dosage gradually being increased until benefit occurs or until adverse effects limit further increments. If patients do not respond to one drug, a trial with another member of the drug class is warranted and may be successful.
Antimuscarinic drugs have a number of undesirable central ner-vous system and peripheral effects and are poorly tolerated by the elderly. Dyskinesias occur in rare cases. Acute sup-purative parotitis sometimes occurs as a complication of dryness of the mouth.
If medication is to be withdrawn, this should be accomplished gradually rather than abruptly to prevent acute exacerbation of parkinsonism. For contraindications to the use of antimuscarinic drugs.