dont no if this is the same compound but it was under sources on a chem website
RESULTS
PD 0200390 was rapidly absorbed; mean time to maximum plasma concentration was 1.66–3.24 h. Mean half-life in subjects with normal renal function was 5.36 h, and increased with worsening RI. Oral (CL/F) and renal (CLR) clearance rates decreased with deteriorating renal function, whereas area under the concentration–time curve (AUC0–∞) values increased by 56, 117 and 436% in subjects with mild, moderate and severe RI, respectively, indicating increased PD 0200390 exposure. Regression analysis demonstrated that CL/F and CLR correlated with CLcr (r= 0.953 and 0.961, respectively). PD 0200390 was well tolerated in subjects with mild, moderate or no RI. The most common adverse events were somnolence, dizziness and headache; these occurred with greatest intensity in the severe RI group.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2767279/?tool=pmcentrez
somnolence, dizziness=euphoria? i know from experience with pregablin that high doses have caused the most euphoria from any compound I have ever consumed
found some dosage information
Single- and multiple-dose studies of the safety and pharmacokinetics of PD 0200390 in a total of 84 healthy human subjects indicated that PD 0200390 is safe and well tolerated at single doses up to 150 mg and multiple doses up to 100 mg twice daily and 150 mg once daily for 14 days [8, 9]. A dose-proportional pharmacokinetic profile with low intersubject variability was observed in these subjects. The half-life of 5–6 h and time to reach maximum plasma concentration (Cmax) of 1.3 h, associated with 50% of maximal pharmacodynamic response (EC50) occurring at plasma concentrations of 1.1–1.6 µg ml−1 for pharmacodynamic measures of sleepiness (visual analogue scale for sleepiness and Stanford Sleepiness Scale), were consistent with potential efficacy in sleep onset and maintenance, and minimal risk of next-day effects with appropriate dosing [8].
so 150mg is the max dose they could say was well tollerated.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2767279/?tool=pmcentrez