Regadenoson can be safely administered as a fixed unit bolus and is as efficacious as adenosine in detecting ischemia regardless of age, gender, body mass index, and diabetes. Regadenoson is better tolerated overall and across various subgroups.

Dapoxetine is being developed as a treatment for premature ejaculation and has demonstrated rapid absorption and elimination in previous pharmacokinetic studies. Two open-label studies were conducted in healthy men: a parallel-group pharmacokinetic and safety study in young and elderly men and a randomized crossover food-effect study. Maximal plasma dapoxetine concentrations (C(max)) were similar in young and elderly men (338 and 310 ng/mL, respectively), as were the corresponding area under the plasma concentration versus time curve (AUC) values (2040 and 2280 ng x h/mL, respectively). When coadministered with food, C(max) was reduced by 11% (398 vs 443 ng/mL in the fed and fasted states, respectively), and the peak was delayed by approximately 30 minutes, indicating that food slowed the rate of absorption; however, systemic exposure to dapoxetine (ie, AUC) was not affected by food consumption. Thus, age or consumption of a high-fat meal has only a modest impact on dapoxetine pharmacokinetics in healthy men.

GS-9667, a new selective, partial agonist of the A(1) adenosine receptor (AR), may represent an effective therapy for Type 2 diabetes (T2DM) and dyslipidemia via lowering of free fatty acids (FFA). The objectives of the studies were to evaluate the effects of single and multiple doses of GS-9667 on plasma FFA concentrations, its pharmacokinetics (PK) and safety/tolerability. Two studies were conducted. In the single ascending dose study, healthy, non-obese, and obese subjects received a single oral dose of GS-9667 (30-1,800 mg). In the multiple, ascending dose study, healthy, obese subjects received GS-9667 (600-2,400 mg QD, 1,200 mg BID, or 600 mg QID) for 14 days. Blood and urine samples were collected for lipid profiling and PK analyses. The ECG, vital signs, and subject tolerability were monitored. Doses of GS-9667 ≥300 mg caused dose-dependent reductions in FFA levels that were reproducible over 14 days without evidence of desensitization or rebound. All doses were well tolerated. GS-9667 was rapidly absorbed and distributed; Steady-state concentrations were achieved within 3-5 days. The A(1) AR partial agonist GS-9667 reduced plasma FFA, exhibited linear kinetics, and was well-tolerated in healthy non-obese and obese subjects.

Selective serotonin reuptake inhibitors (SSRIs) may be associated with electrocardiographic effects. The electrocardiographic pharmacodynamics of dapoxetine, a short-acting SSRI being developed for the treatment of premature ejaculation, are compared with those of placebo and moxifloxacin (positive control) in 2 single-center, randomized, crossover studies in healthy men. In study 1, subjects receive 2 doses of dapoxetine 120 mg, given 3 hours apart; a single dose of moxifloxacin 400 mg; and 2 doses of placebo, given 3 hours apart. In study 2, subjects receive single doses of dapoxetine 60 mg, dapoxetine 120 mg, moxifloxacin 400 mg, and placebo. Moxifloxacin significantly increases QT and corrects QT intervals (QTc) compared with placebo in both studies (eg, Bazett-corrected QTc of 11.90 milliseconds [95% confidence interval, 2.68 to 21.11] and 5.06 [95% confidence interval, -2.26 to 12.38]). Dapoxetine 60, 120, and 240 mg do not prolong the QT/QTc interval and have no clinically significant electrocardiographic effects. Dapoxetine and moxifloxacin pharmacokinetics are similar to previous reports. Adverse events are generally mild in severity; nausea is the most common. The results demonstrate that dapoxetine does not have electrocardiographic effects at doses of 60, 120, and 240 mg.

BMI does not alter the efficacy of regadenoson MPI despite lower PRC in high BMI subjects, or its side effect profile despite higher PRC in low BMI subjects. Regadenoson is better tolerated than adenosine but this benefit seems to lose statistical significance in subjects with BMI < 25 kg/m(2).