Tolerability and safety profile of pramipexole in the treatment of Parkinson's disease

Information regarding the tolerability and safety of pramipexole is derived primarily from clinical trials designed to examine the efficacy of this ag ent in the treatment of Parkinson's disease. In this review, the adverse ev ent frequencies for pramipexole have been compared with those for placebo, where such information has been provided in accounts of placebo-controlled, double-blind trials. Analyses have been conducted on combined data from th ree studies involving patients with early Parkinson's disease and from five studies involving patients with advanced Parkinson's disease; an analysis was also carried out on combined data from all eight trials. Although prami pexole has been investigated in depression, schizophrenia, restless legs sy ndrome, and in a variety of other conditions, medication-related adverse ev ents noted in such studies have not been considered in the present analysis . The adverse event profiles for pramipexole, as used in early or advanced Parkinson's disease, have been based on only those events for which the fre quency with pramipexole was (a) at least 2.5%, (b) at least 5% greater than that with placebo, and (c) different from that with placebo to a statistic ally significant degree. For all eight studies combined, the resultant prof ile comprised only three symptoms: nausea, somnolence and hallucinations. F or patients with early Parkinson's disease, the profile consisted of somnol ence, nausea, hallucinations, constipation and dizziness; for patients with advanced Parkinson's disease, the profile consisted of dyskinesias, nausea , hallucinations, confusion and insomnia. It is suggested that the dyskinet ic adverse events seen with pramipexole in patients with advanced Parkinson 's disease may in part reflect the concomitant administration of L-DOPA at too high a dose. In this review, other classes of reported adverse event ha ve been noted, though in all cases their frequencies of occurrence were sim ilar to, or sometimes less than, those seen with placebo treatment, and, ex cept for a few of these events, there is little or no clear evidence of the ir causal relationship with pramipexole. in general, those adverse events w hich do appear to be associated with pramipexole treatment are mild-to-mode rate in intensity, though adverse events may occasionally lead patients to withdraw from pramipexole treatment, or necessitate a reduction in the dose of pramipexole. It is concluded that pramipexole is a well tolerated treat ment in both early and advanced Parkinson's disease.