Therapeutic Research

Abstract

Objectives: To investigate the safety and effectiveness of BI・Sifrol(R) （pramipexole） tablets in patients with idiopathic restless legs syndrome（RLS） for long –term real world use. Method: This post marketing surveillance（PMS） was an observational study under routine medical practice. This was a prospective study using a central registration method. Patients with idiopathic RLS were included in the PMS. No specific criteria（e.g.,demographics, baseline characteristics, concomitant drugs in use） were defined for patient enrolment. Safety: There were no new concerns for the safety profile of pramipexole in patients with RLS. The frequencies of patients with adverse events（AEs） and drug–related AEs were 19.4％ and 15.1％ , respectively. Nausea（2.7％） was the most frequent AE, followed by somnolence（2.0％）. Nausea（2.7％） was the most frequent drug– related AE as well, followed by somnolence（1.8％）. Serious AEs（SAEs） were experienced by 10（2.0％）patients. There were 3 drug–related SAEs in 3 patients: ileus, impulse control disorders, and somatic hallucination. Nausea and dizziness were experienced by 5 patients, respectively, followed by headache and RLS （aggravation of RLS） by 4 patients. One patient died by cerebral infarction and it was not drug– related. Augmentation occurred in 5（1.0％）patients, and sudden onset of sleep（SOOS） occurred in 2（0.4％） patients as an AE. In 4 out of 5 patients who experienced augmentation, and all patients who experienced SOOS, these AEs were drug–related. Efficacy: In this PMS, the mean change in International RLS rating scale（IRLS） total score from baseline at the end of obser vation was -15.1（Mixed–effect Model with Repeated Measures: MMRM）. Since the change in IRLS total score of 10 or more points indicates an improvement in at least one stage of RLS severity, the result of the PMS study confirmed an important finding that pramipexole treatment clinically improves the symptoms of RLS in a routine clinical practice. In addition, both Pittsburgh Sleep Quality Index（PSQI） total score for assessing quality of sleep, and the Japanese version of the Epworth Sleepiness Scale（JESS） total score for assessing sleepiness in daily activities showed reductions after 12 months of treatment with pramipexole. Overall conclusions: With the results of this PMS, pramipexole is concluded to be effective and safe in Japanese patients with idiopathic RLS for long –term real world use.