February 2001
Hagell P, Odin P
Apomorphine is a potent, non selective, direct acting dopamine-receptor
agonist. Given subcutaneously, it has a rapid onset of antiparkinsonian
action qualitatively comparable to that of levodopa.
Despite its long
history, it was not until peripheral dopaminergic side effects could be
controlled by oral domperidone that the clinical usefulness of
apomorphine in Parkinson's disease began to be investigated thoroughly
in the mid-1980s. Although several routes have been tried, subcutaneous
administration, either as intermittent injections or continuous
infusion, is so far the best and most applied in the treatment of
advanced, fluctuating Parkinson's disease.
Clinical trials have shown
stable efficacy with markedly reduced time spent in "off" phases as well
as, for infusion therapy, reduced levodopa requirements. In the most
successful cases, motor fluctuations disappear and the need for oral
medication is eliminated. Adverse events are usually mild and dominated
by cutaneous reactions. Neuropsychiatric side effects occur, but the
influence of apomorphine on these remains controversial.
Controlled
long-term clinical trials are highly warranted to reveal the full
potentials of this treatment. Careful patient selection and follow-up,
where the specialized movement disorder nurse has a crucial role, are
paramount for a successful long-term outcome. Apomorphine warrants a
wider application in the treatment of advanced Parkinson's disease and
should be tried before more invasive interventions are considered.
