Safety and efficacy of esreboxetine in patients with fibromyalgia: a fourteen-week, randomized, double-blind, placebo-controlled, multicenter clinical trial.

OBJECTIVE: To evaluate the efficacy, tolerability, and safety of multiple fixed dosages of esreboxetine for the treatment of fibromyalgia. METHODS: Patients meeting the American College of Rheumatology criteria for fibromyalgia were randomized to receive esreboxetine at dosages of 4 mg/day (n=277), 8 mg/day (n=284), or 10 mg/day (n=283) or matching placebo (n=278) for 14 weeks. The primary efficacy outcomes were the weekly mean pain score and the Fibromyalgia Impact Questionnaire (FIQ) total score at week 14. Secondary efficacy measures included scores for the Patient's Global Impression of Change (PGIC) scale, the Global Fatigue Index (GFI), and the 36-item Short-Form health survey (SF-36; physical function scale only) at week 14. The safety profile of esreboxetine was evaluated based on adverse events and other safety measures. RESULTS: Patients receiving all dosages of esreboxetine demonstrated statistically significant improvements in the pain score (P≤0.025), the FIQ score (P≤0.023), and the PGIC score (P≤0.007) compared with patients in the placebo group. Additionally, patients receiving esreboxetine at dosages of 4 mg/day and 8 mg/day showed statistically significant improvements in the GFI score compared with those receiving placebo (P=0.001). No significant differences in SF-36 physical function scores were observed between patients receiving esreboxetine (any dosage) and those receiving placebo. Adverse events were mostly mild to moderate in severity; insomnia, constipation, dry mouth, nausea, dizziness, hot flush, headache, hyperhidrosis, and palpitations were reported most frequently. CONCLUSION: Esreboxetine was generally well tolerated and was associated with significant improvements in pain, FIQ, PGIC, and fatigue scores compared with placebo. The lack of a dose-response relationship in both the efficacy and safety analyses suggests that esreboxetine at a dosage of 4 mg/day would offer clinical benefit with the least risk of drug exposure.

Validation of the Chinese Western Ontario and McMaster Universities Osteoarthritis Index in Patients From Mainland China With Osteoarthritis of the Knee.

OBJECTIVE: To establish the reliability, validity, and sensitivity to change of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) among Chinese subjects with osteoarthritis (OA) of the knee, living in mainland China. METHODS: A multicenter, randomized, double-blind, placebo-controlled, parallel-group study was conducted for validation of the electronic personal digital assistant version of the WOMAC Numerical Rating Scale (NRS) 3.1 Index in China. A total of 287 subjects with OA of the knee were randomized to receive either meloxicam (15 mg) or placebo. Psychometric properties of the WOMAC were evaluated by estimating the reliability, validity, and sensitivity to change. Equivalence of the electronic version was also compared with the paper version. RESULTS: Intraclass correlation coefficients for the WOMAC pain, stiffness, and physical function subscales were 0.81, 0.76, and 0.85, respectively, indicating good test-retest reliability. Similarly, internal consistency was strong (Cronbach's alpha for the 3 WOMAC subscales was 0.84, 0.86, and 0.96, respectively). Pearson's correlation coefficients for WOMAC pain and Short Form 36 health survey (SF-36) bodily pain, as well as WOMAC physical function and SF-36 physical functioning domains were >0.4, indicating convergent validity, whereas the coefficients for all 3 WOMAC domains with SF-36 mental health and mental health component scores were <0.4, indicating divergent validity. There was strong discriminant validity between healthy volunteers and OA patients. The effect sizes of change from baseline to week 12 in WOMAC subscale scores were large, demonstrating sensitivity to change. Equivalence between paper and electronic versions was very high. CONCLUSION: The culturally and linguistically validated Chinese version of the WOMAC NRS 3.1 for mainland China is psychometrically robust in its validity, reliability, and sensitivity to change for patients with OA of the knee.

Haemodynamic effects of the selective phosphodiesterase 5 inhibitor, UK-357,903, in conscious SHR.

1. Regional haemodynamic responses to a continuous, 4-day infusion of the selective phosphodiesterase type 5 inhibitor, UK-357,903 (0.133 or 1.33 mg x kg(-1) h(-1)) were measured in conscious spontaneously hypertensive rats, and compared with those of enalapril (1 mg x kg(-1) h(-1)). 2. Both doses of UK-357,903 caused modest reductions in mean blood pressure that were not dose-dependent and only significantly different from the vehicle effects on Day 1 of the study (mean -11.8 and -15.3 mmHg for low and high doses, respectively). UK-357,903 had mesenteric and hindquarters vasodilator effects, which were, again, similar for both dose levels and only significantly different from vehicle on Day 1. Neither dose of UK-357,903 affected renal vascular conductance or heart rate. 3. Although the haemodynamic effects of UK-357,903 were not clearly dose-related and some appeared to wane with time, geometric mean plasma levels of UK-357,903 increased in proportion to dose, and were sustained throughout the infusion period. Furthermore, plasma cyclic guanosine monophosphate, a biomarker of phosphodiesterase 5 inhibition, was persistently elevated, and increased with increasing dose. 4. Enalapril caused a fall in mean blood pressure on day 1 (-14.1 mmHg) that was associated with dilatation in renal, mesenteric and hindquarters vascular beds. The haemodynamic effects of enalapril were sustained or increased over the 4-day infusion, although plasma free drug levels were stable. 5. In conclusion, we have shown regional and temporal changes in the haemodynamic effects of UK-357,903, which may be due to activation of compensatory mechanisms, but there were no signs of functional compensation to the cardiovascular effects of enalapril.

Stabilization versus inhibition of TAFIa by competitive inhibitors in vitro.

Two competitive inhibitors of TAFIa (activated thrombin-activable fibrinolysis inhibitor), 2-guanidinoethylmercaptosuccinic acid and potato tuber carboxypeptidase inhibitor, variably affect fibrinolysis of clotted human plasma. Depending on their concentration, the inhibitors shortened, prolonged, or had no effect on lysis in vitro. The inhibitor-induced effects were both tissue-type plasminogen activator (tPA) and TAFIa concentration-dependent. Inhibitor-dependent prolongation was favored at lower tPA concentrations. The magnitude of the prolongation increased with TAFIa concentration, and the maximal prolongation observed at each TAFIa concentration increased saturably with respect to TAFIa. A theoretical maximal prolongation of 20-fold was derived from a plot of the maximum prolongation versus TAFIa. This represents, for the first time, a measurement of the maximal antifibrinolytic potential of TAFIa in vitro. Because TAFIa spontaneously decays, the stabilization of TAFIa was investigated as a mechanism explaining the inhibitor-dependent prolongation of lysis. Both inhibitors stabilized TAFIa in a concentration-dependent, non-saturable manner. Although their KI values differed by three orders of magnitude, TAFIa was identically stabilized when the fraction of inhibitor-bound TAFIa was the same. The data fit a model whereby only free TAFIa decays. Therefore, the variable effects of competitive inhibitors of TAFIa on fibrinolysis can be rationalized in terms of free TAFIa and lysis time relative to the half-life of TAFIa.