APOMORPHINE IN PATIENTS WITH PARKINSONS-DISEASE

We present a review of the recent literature and personal experience w ith apomorphine in patients with Parkinson's disease. Apomorphine is a potent D-1 and D-2 dopaminergic agonist. It has a rapid and short dur ation effect after subcutaneous administration at doses ranging from 1 5 to 180 mu g/kg. Plasma maximal concentration is reached in 8-16 minu tes: with a plasma half life of 34-70 minutes. Bioavailability is clos e to 100%. Repeated injections in patients show post-stimulative hypos ensitivity. Apomorphine test appears very useful for the differential diagnosis between idiopathic Parkinson's disease and other Parkinson p lus syndromes, and as a predictive test for dopaminergic responsivenes s. Appropriate doses are able to alleviate akinesia, rigidity and trem or. Recent therapeutic trials have demonstrated the high interest of i ntermittent multiple subcutaneous apomorphine injections to cut the '' off'' motor phases in fluctuating parkinsonian patients under chronic levodopa treatment. In somes cases, continuous apomorphine subcutaneou s infusion with a portable pump may be required, particularly when lev odopa treatment is temporarily interrupted, as after abdominal sugery. During long-term treatment, the apomorphine dose able to relieve akin esia remains stable. Peripheral side effects such as nausea and hypote nsion may be prevented by the co-administration of domperidone, a peri pheral dopaminergic antagonist. Cutaneous fibrous nodules and psychiat ric symptoms may occur, but usually al high dosages with continuous in fusion. Local allergic effects have limited the use of other routes of administration, such as intranasal, sublingual, and rectal routes. Ap omorphine is also used as a pharmacological tool for clinical research with the aim of a better understanding of the pathophysiology of Park inson's disease.