Influence of the nonergot dopamine agonist piribedil on vigilance in patients With Parkinson Disease and excessive daytime sleepiness (PiViCog-PD): an 11-week randomized comparison trial against pramipexole and ropinirole.

OBJECTIVES: The aim of this study was to investigate the effects of piribedil on vigilance and cognitive performance in patients with Parkinson disease experiencing excessive daytime sleepiness on pramipexole or ropinirole. METHODS: In this 11-week randomized, active-controlled, rater-blinded phase III study, eligible patients were randomly assigned to either receive piribedil or to continue on pramipexole or ropinirole. The primary outcome was the median reaction times during the second 15 minutes of the subtest "vigilance" of the Test battery for Attention Performances (TAP). Secondary outcomes included the Epworth Sleepiness Scale, Unified Parkinson's Disease Rating Scale, neuropsychological testing, and items of the Clinical Global Impression. RESULTS: Forty-four patients received piribedil; 36 continued on either pramipexole or ropinirole. There was no difference in the primary end point reaction time of the TAP subtest vigilance between piribedil and the comparator (996 vs 954 milliseconds, P = 0.68). Piribedil reduced daytime sleepiness with lower Epworth Sleepiness Scale scores at the end of treatment compared with the comparator (-4 vs -2 points; P = 0.01). The median Unified Parkinson's Disease Rating Scale III score at the end of treatment was comparable between the 2 groups. Neuropsychological tests revealed no significant between-treatment differences. A higher therapeutic effect and global improvement were shown by the Clinical Global Impression of piribedil-treated patients. CONCLUSIONS: This study shows that switching from pramipexole or ropinirole to piribedil has no effect on the reaction time of the TAP subtest vigilance but upholds the same therapeutic motor effect and reduces daytime sleepiness to a clinically relevant degree in patients with excessive daytime sleepiness.

Bioequivalence of a novel high-dose oral formulation of alpha-dihydroergocryptine.

The plasma pharmacokinetics of alpha-dihydroergocryptine (DHEC, CAS 14271-05-7) were investigated in 24 patients with Parkinson disease after the administration of repeated oral doses of 40 mg DHEC twice daily by means of a novel 40 mg DHEC tablet (Almirid 40 mg test T) and an established 20 mg DHEC tablet (Almirid 20 mg - reference R). The trial was conducted according to a randomised, controlled, open, within-subject cross-over design; steady-state was established by means of a stepwise up-titration from 5 to 40 mg b.i.d. from day D01 to D19; investigational treatments (40 mg DHEC b.i.d. by means of formulation R and T) were administered on day D20 and D21 according to a randomised, period-balanced within-subject cross-over; treatment with DHEC was down-titrated in stepwise fashion from day D22 to D34. Morning doses of 2 x 20 mg DHEC (reference) yielded a fast and relatively short lasting peak with a geometric mean Cmax of 2157 pg/mL (CV: 0.978) after a median tmax of 1.00 h. Cmin throughout the first 12 h was on average 189 pg/mL (CV: 0.908). There was a quite distinct diurnal effect: evening doses of 2 x 20 mg DHEC (treatment R), yielded a relatively lower exposure with geometric mean Cmax, Cav- and Cmin-values of 800 pg/mL (CV: 0.870), 389 pg/mL (0.813) and 177 pg/mL (CV: 0.942). In contrast, there was relatively little within-subject distinction between the two formulations: for the day profile after the morning dose, the estimated ratios of the true means (Pr:R) for Cmax Cmin and Cav were 1.18 (90% CI: 0.96 to 1.43 - CVm: 0.394), 0.96 (90% CI: 0.86 to 1.09 - CVm: 0.230) and 1.06 (90% CI: 0.93 to 1.21 - CVm: 0.254); for the night profile after the evening dose, the estimated ratio of the true means (muT:muR) for Cmax, Cmin and Cav were 1.11 (90% CI: 0.91 to 1.35 - CVm: 0.395), 1.07 (90% CI: 0.95 to 1.20 - CVm: 0.232) and 1.07 (90% CI: 0.95 to 1.20 - CVm: 0.220). In view of important medical-ethical constraints not to expose an unreasonably high number of subjects, these findings could be accepted as a sufficient demonstration of bioequivalence.

In vivo biopharmaceutical characterisation of a new formulation containing the antiepileptic drug lamotrigine in comparison to plain and dispersible/chewable lamotrigine tablets.

AIM: Two studies in healthy male volunteers were carried out to evaluate the pharmacokinetic profile of a new divisible formulation of lamotrigine (CAS 84057-84-1, Plexxo, Lamotrigin Desitin) in plasma in comparison to plain or dispersible lamotrigine tablets. METHODS: The plasma pharmacokinetics of lamotrigine were analysed after administration of single doses of 100 mg lamotrigine given as one tablet of the new formulation and either the plain or the dispersible reference formulation in two separate studies. In each study the data of 24 subjects were analysed according to the study protocol. Venous blood samples were taken at appropriate intervals up to 120 h after dosing. Concentrations of lamotrigine were determined in plasma by a validated HPLC method using UV detection. RESULTS AND CONCLUSION: In both studies, mean plasma concentration-time profiles of the new lamotrigine formulation and both reference formulations ran nearly in parallel. The pharmacokinetic mean data calculated from different subject groups of the two studies were very similar. The mean ratios of the main pharmacokinetic parameters and the corresponding 90% confidence intervals of AUC(0-t), AUC(0-inf) and C(max) were 103% (99.7-105.7), 103% (99.6-107.3) and 101% (95.2-106.6) for the comparison with the plain lamotrigine tablet and 100% (98.0-102.8), 100% (96.5-102.8) and 102% (99.1-105.3) for the comparison with the dispersible/chewable tablet, respectively. The most frequently reported adverse events possibly related to the administration of lamotrigine were headache and dizziness in both studies. It is concluded that the new divisible lamotrigine formulation is bioequivalent with regard to rate and extent of absorption to both the plain reference lamotrigine product and to the dispersible/chewable reference product.

Determination of dihydroergocryptine in human plasma and urine samples using on-line sample extraction-column-switching reversed-phase liquid chromatography-mass spectrometry.

A rapid and sensitive assay for the determination of dihydroergocryptine (DHEC) in human plasma and urine samples with dihydroergotamine (DHET) as the internal standard was developed. The procedure employs on-line sample preparation using an extraction pre-column and an octadecylsilylsilica (ODS) analytical column. After centrifugation human plasma or urine were injected onto the pre-column, concentrated and extracted, back-flushed onto the analytical column and eluted with a binary methanol--aqueous formic acid gradient. Either determination of DHEC as well of its mono- and dihydroxy-metabolites was performed by measurement of the signal responses from MS detection in the selected reaction monitoring (SRM) mode using the transition of the respective parent ions to the common daughter ion at m/z=270.2 amu. The limit of quantitation (LOQ) for determinations of DHEC in both plasma and urine were 25 pg/ml for injected sample volumes of 400 microl. Proportionality of signal responses versus concentration was accomplished within the range of 25-1000 pg/ml. Recovery of target analyte from plasma was 99%. Mean values of the coefficients of variation (CV) for the target analyte in plasma ranged from 1.7 to 13.8% (within-day) and 5.0 to 9.1% (between-day) and accuracy from 91.7 to 102.6% for the within-day and from 95.8 to 98.8% for the between-day measurements. The corresponding values for determinations in urine were 1.7-14.5% (within-day) and 5.3-11.8% (between-day) for CV and 95.8-110.7% (within-day) and 100.1-104.6% (between-day) for accuracy.