Efficacy and safety of hydroxyzine in the treatment of generalized anxiety disorder: a 3-month double-blind study. A multicentre double-blind comparison of hydroxyzine, buspirone and placebo in patients with generalized anxiety disorder. Outcome reporting in industry-sponsored trials of gabapentin for off-label use.
The prevalence of generalized anxiety disorder (GAD) represents an important public health issue. Hydroxyzine, an antagonist of histamine receptors, showed both efficacy and safety in previous short-term double-blind studies over placebo in this pathology. The aim of the current study was to confirm those positive results over a 3-month period in adult outpatients.
                This multicenter, parallel (hydroxyzine [50 mg/day]; bromazepam [6 mg/day]), randomized, double-blind, placebo-controlled trial included 2 weeks of single-blind run-in placebo, 12 weeks of double-blind randomized treatment, and 4 weeks of single-blind run-out placebo. Three hundred thirty-four of 369 selected outpatients with a diagnosis of GAD according to DSM-IV criteria and a Hamilton Rating Scale for Anxiety (HAM-A) total score >/= 20 were randomized before entering the double-blind period. The primary outcome criterion was the change in the HAM-A score from baseline to 12 weeks of double-blind treatment with hydroxyzine compared with placebo.
                In the intent-to-treat analysis, the mean +/- SD change in HAM-A scores from baseline to endpoint was -12.16 +/- 7.74 for hydroxyzine and -9.64 +/- 7.74 for placebo (p =.019). Results at endpoint for percentage of responders (p =.003) and remission rates (p =.028), Clinical Global Impressions-Severity scale score (p =.001), maintenance of efficacy (p =.022), and Hospital Anxiety and Depression scale score on day 84 (p =.008) also confirmed the efficacy of hydroxyzine over placebo. The study showed no statistically significant difference between hydroxyzine and bromazepam. Except for drowsiness, which was more frequent with bromazepam, safety results were comparable in the 3 groups.
                Hydroxyzine showed both efficacy and safety in the treatment of GAD and appears to be an effective alternative treatment to benzodiazepine prescription. The efficacy of hydroxyzine and buspirone, controlled by placebo, was investigated in a double-blind, parallel group, multicentre study conducted in France and the UK. A total of 244 patients with generalised anxiety disorder in primary care was allocated randomly to treatments with hydroxyzine (12.5 mg morning and mid-day, 25 mg evening), buspirone (5 mg morning and mid-day, 10 mg evening) or placebo (three capsules/day) for 4 weeks, preceded by a 1-week single-blind placebo run-in and followed by 1-week single-blind placebo administration. Rating scales were applied on days -7,0,7,14, 12,28 and 35. Seventy percent of the patients were female, the average age was 41 +/- 11 years, and the mean Hamilton Anxiety Score at day 0 was 26.5 +/- 4.2. Only 31 of the 244 patients dropped out, but equally in the three groups. Intention-to-treat LOCF analyses on the primary variable showed a significant difference only between hydroxyzine and placebo with respect to improvement on the Hamilton Anxiety Scale (10.75 versus 7.23 points, respectively). Secondary variables such as CGI and self-ratings (HAD scale) showed both hydroxyzine and buspirone to be more efficacious than placebo. Thus, hydroxyzine is a useful treatment for GAD. There is good evidence of selective outcome reporting in published reports of randomized trials.
                We examined reporting practices for trials of gabapentin funded by Pfizer and Warner-Lambert's subsidiary, Parke-Davis (hereafter referred to as Pfizer and Parke-Davis) for off-label indications (prophylaxis against migraine and treatment of bipolar disorders, neuropathic pain, and nociceptive pain), comparing internal company documents with published reports.
                We identified 20 clinical trials for which internal documents were available from Pfizer and Parke-Davis; of these trials, 12 were reported in publications. For 8 of the 12 reported trials, the primary outcome defined in the published report differed from that described in the protocol. Sources of disagreement included the introduction of a new primary outcome (in the case of 6 trials), failure to distinguish between primary and secondary outcomes (2 trials), relegation of primary outcomes to secondary outcomes (2 trials), and failure to report one or more protocol-defined primary outcomes (5 trials). Trials that presented findings that were not significant (P > or = 0.05) for the protocol-defined primary outcome in the internal documents either were not reported in full or were reported with a changed primary outcome. The primary outcome was changed in the case of 5 of 8 published trials for which statistically significant differences favoring gabapentin were reported. Of the 21 primary outcomes described in the protocols of the published trials, 6 were not reported at all and 4 were reported as secondary outcomes. Of 28 primary outcomes described in the published reports, 12 were newly introduced.
                We identified selective outcome reporting for trials of off-label use of gabapentin. This practice threatens the validity of evidence for the effectiveness of off-label interventions.
                2009 Massachusetts Medical Society
The included studies did not report on all the outcomes that were pre-specified in the protocol for this review. Even though more effective than placebo, due to the high risk of bias of the included studies, the small number of studies and the overall small sample size, it is not possible to recommend hydroxyzine as a reliable first-line treatment in GAD.