Gabapentin exposure was approximately proportional to GEn dose. Efficacy data showed that a once-daily dose of GEn 600 to 2400 mg provides greater relief of RLS symptoms than placebo; GEn was generally well tolerated with an adverse event profile consistent with gabapentin.

Purpose: Solriamfetol (JZP-110), a selective dopamine and norepinephrine reuptake inhibitor with robust wake-promoting effects, is currently being evaluated for the reduction of sleepiness and improvement of wakefulness in patients with narcolepsy and obstructive sleep apnea. The purpose of this study was to evaluate the effect of food on the pharmacokinetic (PK) parameters and bioavailability of solriamfetol at the highest intended therapeutic dose in healthy adults and to characterize its renal excretion under fasting conditions. Methods: In this open-label, randomized, crossover study, healthy adult subjects received a single 300-mg dose of solriamfetol in a fasted condition (10 h) and in a fed condition (30 min after the start of a standardized high-fat, high-calorie breakfast), with at least a 7-day washout period between doses. Blood samples for PK analyses were collected during both conditions at prespecified time points. Urine samples were collected up to 48 h postdose in the fasted condition. Samples were analyzed for solriamfetol (plasma and urine) and N-acetyl solriamfetol (urine) by using validated LC-MS/MS bioanalytical methods. The effect of food on solriamfetol relative bioavailability was examined by comparing the 90% confidence intervals (CIs) of the fed/fasted ratios of natural log-transformed PK parameters C max , AUC 0et , and AUC 0e∞ with the prespecified range of 80%e 125%. Safety and tolerability were also assessed. Findings: A total of 32 subjects were enrolled (50% female; 53.1% black, 46.9% white; mean age, 35.6 years), and 31 were included in the PK analyses. Solriamfetol was rapidly absorbed in both conditions. The 90% CIs for the fed/fasted geometric mean ratios were 89.2e98.8 for C max (ratio of 93.9%) and 93.8e101.5 for AUC 0e∞ (ratio of 97.6%), indicating the absence of a food effect. In the fasted condition, 89.8% of solriamfetol was recovered in urine as unchanged drug over 48 h; 1.1% was excreted as a minor metabolite, N-acetyl solriamfetol. A total of 55 adverse events (AEs), all mild, were reported by 18 subjects (56.3%). The frequency and type of AEs were similar in the 2 conditions; the most common AEs (insomnia, headache, hypervigilance, decreased appetite, and nausea) were all mild in severity and resolved without treatment. Implications: Solriamfetol relative bioavailability was bioequivalent in the fed and fasted conditions, showing that solriamfetol can be taken without regard to meals; furthermore, tolerability was similar in both conditions. Renal excretion of unchanged drug is the primary route of elimination. (Clin Ther.

The objective of this study was to assess the efficacy, safety, and pharmacokinetics of XP21279-carbidopa in patients with Parkinson's disease who experience motor fluctuations compared with immediate-release carbidopa-levodopa tablets. XP21279 is a levodopa prodrug that is actively absorbed by high-capacity nutrient transporters expressed throughout the gastrointestinal tract and then rapidly converted to levodopa by carboxylesterases. XP21279-carbidopa sustained-release bilayer tablets were developed to overcome pharmacokinetic limitations of levodopa by providing more continuous exposure. Patients with motor fluctuations who required carbidopa-levodopa four or five times daily were optimized for 2 weeks each on carbidopa-levodopa four or five times daily and XP21279-carbidopa three times daily in a randomized sequence. Next, they received each optimized treatment for 2 weeks in a double-blind/double-dummy, randomized sequence. The primary outcome measure was change from baseline in daily off time at the end of each double-blind treatment period. All patients at 2 sites underwent pharmacokinetic analyses. Twenty-eight of 35 enrolled patients completed both double-blind treatments. The mean total daily off time was reduced from baseline by a mean (± standard error) of 2.7 hours (± 0.48 hours) for immediate-release carbidopa-levodopa and 3.0 hours (± 0.57 hours) for XP21279-carbidopa (P = 0.49). Among 11 patients who completed pharmacokinetic sampling on each optimized treatment, the percentage deviation from the mean levodopa concentration was lower (P < 0.05) for XP21279-carbidopa than carbidopa-levodopa. Both treatments had a similar incidence of new or worsening dyskinesias. XP21279-carbidopa administered three times daily produced a reduction in off time similar to that of carbidopa-levodopa administered four or five times daily, and the difference was not statistically significant. XP21279-carbidopa significantly reduced variability in levodopa concentrations compared with carbidopa-levodopa.

are full-time employees of Jazz Pharmaceuticals who, in the course of this employment, have received stock options exercisable for, and other stock awards of, ordinary shares of Jazz Pharmaceuticals, plc. Jack Jenkins is a non-employee consultant paid by Jazz Pharmaceuticals.

No abstract