A multi-center, double-blind study of slow-release bromocriptine in the treatment of Parkinson's disease

Parkinsonism results from a deprivation of part of the brain of its normal nerve input. This input uses dopamine as its neurotransmitter substance, and much of the therapy aimed at Parkinson's disease attempts to supplement the dopamine available to this area. Drugs that act directly on the dopamine receptor, called dopamine agonists, are useful, but cause serious gastrointestinal discomfort. Since it is thought that much of this discomfort occurs when the stomach and intestines are subjected to a large amount of drug after taking an oral dose, it may prove useful to use slow-release preparations, which dissolve slowly and do not insult the stomach with the full dose of drug all at once. This hypothesis was tested using the dopamine agonist drug bromocriptine. A total of 243 patients with Parkinson's disease were randomly assigned to receive either a slow-release preparation or a standard preparation of bromocriptine. The dose of the drug was incremented so that the final drug dose was not administered until six weeks after the start of treatment. Neither group experienced any serious side effects, but gastric discomfort and vomiting were significantly reduced among the patients who received the slow-release formulation. This was reflected in the patient drop-out rate; fewer patients taking the slow-release formula dropped out of the study due to side effects. The patients receiving the slow-release preparation also experienced an improvement of parkinsonian symptoms that was marginally better than the patients taking the standard preparation. However, this difference was not statistically significant. This study confirms the suspicion that slow-release formulations are a superior method for administering bromocriptine to patients with Parkinson's disease. (Consumer Summary produced by Reliance Medical Information, Inc.)