RESULTS:
Extended-release formulations of
pramipexole and
ropinirole and transdermal continuous delivery
rotigotine patches are currently available; these may contribute to stabilising of plasma levels. In early PD, the three drugs significantly improve disability scales, delay time to
dyskinesia and allow a later introduction of
levodopa. In late PD they reduced total 'off'-time, improved Unified Parkinson's Disease Rating Scale (UPDRS) in both 'on' and 'off' state and allowed a reduction in total
levodopa dosage. A significant improvement in quality of life scales has also been demonstrated.
Extended-release formulations have proved to be non-inferior to the immediate release formulations and are better tolerated (
ropinirole). Despite a generally good safety profile, serious adverse events, such as impulse control disorder and sleep attacks, need to be routinely monitored. Although combination
therapy has not been addressed in scientific literature, certain combinations, such as
apomorphine and another DA, may be helpful. Switching from one DA to another is feasible and safe, although in the first days an overlap of dopaminergic side effects may occur. When treatment with DA is stopped abruptly,
dopamine withdrawal syndrome may present. Suspending any DA, especially
pramipexole, has been linked to onset of apathy, which may be severe.
CONCLUSIONS: New non-ergotine
DAs are a valuable option for the treatment of both early and late PD. Despite their good safety profile, serious adverse effects may appear; these effects may have a pathoplastic effect on the course of PD and need to be monitored.