Psychopharmacological treatment of panic disorder and related states: a placebo controlled study of alprazolam

Benzodiazepines versus placebo for panic disorder in adults

BACKGROUND

Panic disorder is characterised by recurrent unexpected panic attacks consisting of a wave of intense fear that reaches a peak within a few minutes. Panic disorder is a common disorder, with an estimated lifetime prevalence of 1% to 5% in the general population and a 7% to 10% prevalence in primary care settings. Its aetiology is not fully understood and is probably heterogeneous.Panic disorder is treated with psychological and pharmacological interventions, often used in combination. Although benzodiazepines are frequently used in the treatment of panic disorder, guidelines recommend antidepressants, mainly selective serotonin reuptake inhibitors (SSRIs), as first-line treatment for panic disorder, particularly due to their lower incidence of dependence and withdrawal reaction when compared to benzodiazepines. Despite these recommendations, benzodiazepines are widely used in the treatment of panic disorder, probably because of their rapid onset of action.

OBJECTIVES

To assess the efficacy and acceptability of benzodiazepines versus placebo in the treatment of panic disorder with or without agoraphobia in adults.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trials Register (CCMDCTR Studies and References), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1950-), Embase (1974-), and PsycINFO (1967-) up to 29 May 2018. We handsearched reference lists of relevant papers and previous systematic reviews. We contacted experts in the field for supplemental data.

SELECTION CRITERIA

All double-blind (blinding of patients and personnel) controlled trials randomising adults with panic disorder with or without agoraphobia to benzodiazepine or placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently checked the eligibility of studies and extracted data using a standardised form. Data were then entered data into Review Manager 5 using a double-check procedure. Information extracted included study characteristics, participant characteristics, intervention details, settings, and outcome measures in terms of efficacy, acceptability, and tolerability.

MAIN RESULTS

We included 24 studies in the review with a total of 4233 participants, of which 2124 were randomised to benzodiazepines and 1475 to placebo. The remaining 634 participants were randomised to other active treatments in three-arm trials. We assessed the overall methodological quality of the included studies as poor. We rated all studies as at unclear risk of bias in at least three domains. In addition, we judged 20 of the 24 included studies as having a high risk of bias in at least one domain.Two primary outcomes of efficacy and acceptability showed a possible advantage of benzodiazepines over placebo. The estimated risk ratio (RR) for a response to treatment was 1.65 (95% confidence interval (CI) 1.39 to 1.96) in favour of benzodiazepines, which corresponds to an estimated number needed to treat for an additional beneficial outcome (NNTB) of 4 (95% CI 3 to 7). The dropout rate was lower among participants treated with benzodiazepines (RR 0.50, 95% CI 0.39 to 0.64); the estimated NNTB was 6 (95% CI 5 to 9). We rated the quality of the evidence as low for both primary outcomes. The possible advantage of benzodiazepine was also seen for remission (RR 1.61, 95% CI 1.38 to 1.88) and the endpoint data for social functioning (standardised mean difference (SMD) -0.53, 95% CI -0.65 to -0.42), both with low-quality evidence. We assessed the evidence for the other secondary outcomes as of very low quality. With the exception of the analyses of the change score data for depression (SMD -0.22, 95% CI -0.48 to 0.04) and social functioning (SMD -0.32, 95% CI -0.88 to 0.24), all secondary outcome analyses showed an effect in favour of benzodiazepines compared to placebo. However, the number of dropouts due to adverse effects was higher with benzodiazepines than with placebo (RR 1.58, 95% CI 1.16 to 2.15; low-quality evidence). Furthermore, our analyses of adverse events showed that a higher proportion of participants experienced at least one adverse effect when treated with benzodiazepines (RR 1.18, 95% CI 1.02 to 1.37; low-quality evidence).

AUTHORS' CONCLUSIONS

Low-quality evidence shows a possible superiority of benzodiazepine over placebo in the short-term treatment of panic disorders. The validity of the included studies is questionable due to possible unmasking of allocated treatments, high dropout rates, and probable publication bias. Moreover, the included studies were only short-term studies and did not examine the long-term efficacy nor the risks of dependency and withdrawal symptoms. Due to these limitations, our results regarding the efficacy of benzodiazepines versus placebo provide only limited guidance for clinical practice. Furthermore, the clinician's choice is not between benzodiazepines and placebo, but between benzodiazepines and other agents, notably SSRIs, both in terms of efficacy and adverse effects. The choice of treatment should therefore be guided by the patient's preference and should balance benefits and harms from treatment in a long-term perspective.

Comorbid anxiety in bipolar disorder alters treatment and prognosis

Mood disorders in general, and bipolar disorder in particular, are unique among the psychiatric conditions in that they are associated with extraordinarily high rates of comorbidity with a multitude of psychiatric and medical conditions. Among all the potential comorbidities, co-occurring anxiety disorders stand out due to their very high prevalence. Outcome in bipolar illness is worse in the presence of a comorbid anxiety disorder. The coexistence of an anxiety disorder presents a particularly difficult challenge in the treatment of bipolar illness since antidepressants, the mainstay of pharmacologic treatments for anxiety, may adversely alter the course of manic-depression. Identification of anxiety disorders in bipolar patients is important. The treatment plan needs to balance the potential benefit and harm of antidepressant administration.

Alprazolam in panic disorder: a retrospective analysis

1. The charts of 78 panic disorder outpatients treated with alprazolam (mean dose 4.30 mg/day, mean duration 31.9 months) were reviewed for demographics, past history (including substance abuse and major depression), and evidence of alprazolam abuse. In addition, the patients were evaluated by Clinical Global Index for improvement at last contact. 2. Moderate to significant recovery was found in 77% of patients. Major depression was seen in 41%. Depressed patients were more likely to have coexisting agoraphobia and a past history of alcohol abuse than non-depressives. 3. There was no DSM-III-R anxiolytic abuse, but 12% showed unauthorized use of the alprazolam. These subjects were three times more likely to have a history of drug abuse than non-misusers. 4. These results indicate that alprazolam is effective in the long-term treatment of panic disorder, but that prolonged management may be required. Further, the data raise concerns about use in panic patients with substance abuse histories.

Panic disorder: a biological perspective

Panic disorder (PD) was first delineated as a separate diagnostic entity 25 years ago. It is a prevalent disorder that responds well to pharmacological interventions, most notably to antidepressants and benzodiazepines. PD and other psychiatric disorders, such as generalized anxiety disorder and major depression, overlap clinically, but it is unresolved whether they also overlap biologically. Finally, the pathogenesis of PD is still unclear. Theories linking panic to increased sensitivity to CO2 or serotonin are preliminary, while alpha 2-adrenergic dysregulation in panic is still unproven. However, the development of new, selective, receptor agonists and antagonists in combination with imaging techniques may produce some of the answers to the questions raised since.