Therapeutical and experimental usefulness of apomorphine

Apomorphine induces behavioural changes in man in some way similar to those elicited by low doses of the drug in animals. In fact, in man a complex symptomatology, in which sedation and psycho-motor reduction predominates, is elicited by non-emetic doses of apomorphine. This supports evidence for self-inhibitory DA receptor stimulation also in man which is further confirmed by the fact that the drug has a marked therapeutical efficacy on diseases in which over-activity of the dopaminergic system has a determinant role. In fact, apomorphine is useful in decreasing manic and schizophrenic symptoms, in diminishing abnormal involuntary movements in Huntingtonian patients and in other hyperkinetic syndromes. The well-known improving effect on Parkinson's Disease, however, seems to be related to a stimulation of the 'classic' postsynaptic receptors, which are abnormally supersensitive to the neurotransmitter. The therapeutical use of apomorphine and other dopaminomimetics is actually more feasible.