Apomorphine hydrochloride for the treatment of Parkinson's disease.

Apomorphine (APO) is a potent D1 and D2 dopamine agonist. Plasma maximal concentration is reached in 8-16 min with a plasma half-life of 34-70 min. Bioavailability is close to 100%. It has a rapid antiparkinsonian action after subcutaneous (s.c.) administration with a size effect comparable with that of levodopa. Trials of s.c., oral, sublingual, intravenous, rectal, intranasal and iontophoretic transdermal administration of APO have been attempted in Parkinson's disease (PD), each of these routes have shown some potential for clinical effectiveness but the majority of studies indicate that APO intermittent s.c. administration, on which this review is mainly focused, is an effective therapy for the management of motor symptoms in PD, particularly in advanced phases mainly characterized by motor fluctuations, such as wearing OFF and unpredictable "off". Data on the effect of APO on non-motor symptoms in PD patients are limited but there is strong suggestion of a beneficial effect that warrants further investigation.