Therapeutical efficacy of a combination of apomorphine with sulpiride or metoclopramide in Parkinsonism.

In healthy volunteers the emetic effect of apomorphine (5-10 mg, i.m.) was prevented by haloperidol (2 mg), metoclopramide (10 mg) and sulpiride (100 mg), injected intramuscularly. In parkinsonian patients, apomorphine (1 mg) given alone ameliorated the neurological symptoms (30% improvement in the disability score), but the improvement was accompanied by nausea, vomiting, sedation or sleepiness. Haloperidol (2 mg) prevented not only the emetic effect of apomorphine (10 mg), but also its therapeutic efficacy in parkinsonism. Indeed, the disability score was worsened by the drug combination in some patients. Moreover, after haloperidol, apomorphine produced deep sedation and sleep. By contrast, in parkinsonian patients pretreated with metoclopramide (10 mg) or sulpiride (100 mg), apomorphine (10 mg) markedly diminished tremor and rigidity and failed to produce nausea, vomiting and sleepiness.