The problems of long term treatment with
antiparkinson drugs are numerous, involving increased
involuntary movements, painful dystonic
cramps, decrease or loss of therapeutic benefit, wearing-off, episodes of akinesia (on-off) and long periods of "freezing". Important side effects are also mental changes with heavy dreams,
hallucinations, nocturnal
confusional states and paranoid
psychosis. As most of these side effects are dose-related, they are postponed and lessened by small daily doses of
L-dopa and
decarboxylase inhibitor. Frequent small doses may decrease the wearing-off effect but may cause unpredictable episodes of on-off. The addition of or partial replacement by
bromocriptine may decrease fluctuations and
dyskinesias in many patients. To reduce the side effects such as
nausea,
orthostatic hypotension and mental disturbances, daily doses of 15-30 mg should be built up very slowly. Painful dystonias are related to the off period and respond well to
baclofen. For the treatment of severe psychic disturbances tranquilizers with little or no extrapyramidal side effects, such as
clomethiazole,
benzodiazepine derivatives and (if necessary)
thioridazine, are recommended.
Bromocriptine may also be useful in occasional cases which do not, or no longer, respond to
L-dopa.