Diazepam and propranolol in panic disorder and agoraphobia

Beta-blockers for the treatment of anxiety disorders: A systematic review and meta-analysis

BACKGROUND

Beta-blocker prescriptions for patients with anxiety increased substantially between 2003 and 2018, yet there is no clinical guidance concerning their use. A previous review of propranolol - a beta-blocker - in the treatment of anxiety concluded there was insufficient evidence to support its use. Additional data have been published in the eight years since that review including some evidence for other beta-blockers. We aimed to synthesise all available data on the effectiveness of beta-blockers in the treatment of anxiety disorders in adults.

METHODS

We searched Medline, Embase, PsycINFO, Web of Science, and Trial Registries (September 2023), including randomised controlled trials (RCT), non-randomised control group comparative studies and cross-over trials reporting self- or clinician-reported anxiety symptoms. Study quality was assessed using Cochrane's Risk of Bias tool, with meta-analyses conducted by comparator group using random-effects models.

RESULTS

Searches produced 3068 records, with 10 studies included, of which five were included in meta-analyses (n = 179). There was no evidence for a beneficial effect of beta-blockers compared with either placebo or benzodiazepines in patients with social phobia or panic disorder with/without agoraphobia (p-value for all meta-analyses ≥0.54).

LIMITATIONS

Many of the included studies had small sample sizes, missing data and high or unclear risk of bias.

CONCLUSION

Beta-blockers are increasingly prescribed for anxiety, yet there is a lack of robust evidence of effectiveness. There is a need to understand when and why practitioners are using these drugs, and to undertake a large RCT to provide definitive evidence of whether beta-blockers are an effective and safe treatment for anxiety.

Panic-like escape response elicited in mice by exposure to CO2, but not hypoxia

Exposure to elevated concentrations of CO₂ or hypoxia has been widely used in psychiatric research as a panic provoking stimulus. However, the use of these respiratory challenges to model panic-like responses in experimental animals has been less straightforward. Little data is available, from behavioral and endocrine perspectives, to support the conclusion that a marked aversive situation, such as that experienced during panic attacks, was evoked in these animals. We here compared the behavioral responses of male CB57BL/6 mice during exposure to 20% CO₂ or 7% O₂ and its consequence on plasma levels of corticosterone. We also evaluated whether clinically-effective panicolytic drugs affect the behavioral responses expressed during CO₂ exposure. The results showed that whereas hypoxia caused a marked reduction in locomotion, inhalation of CO₂-enriched air evoked an active escape response, characterized by bouts of upward leaps directed to the border of the experimental cage, interpreted as escape attempts. Corticosterone levels were increased 30min after either of the respiratory challenges used, but it was higher in the hypoxia group. Chronic (21days), but not acute, treatment with fluoxetine or imipramine (5, 10 or 15mg/kg) or a single injection of alprazolam (0.025, 0.05 or 0.1mg/kg), but not of the anxiolytic diazepam (0.025, 0.05 or 0.1 and 1mg/kg) reduced the number of escape attempts, indicating a panicolytic-like effect. Altogether, the results suggest that whereas hypoxia increased anxiety, exposure to 20% CO₂ evoked a panic-like state. The latter condition/test protocol seems to be a simple and validated model for studying in mice pathophysiological mechanisms and the screening of novel drugs for panic disorder.

Brain angiotensin-(1-7)/Mas axis: A new target to reduce the cardiovascular risk to emotional stress

Emotional stress is now considered a risk factor for several diseases including cardiac arrhythmias and hypertension. It is well known that the activation of neuroendocrine and autonomic mechanisms features the response to emotional stress. However, its link to cardiovascular diseases and the regulatory mechanisms involved remain to be further comprehended. The renin-angiotensin system (RAS) plays an important role in homeostasis on all body systems. Specifically in the brain, the RAS regulates a number of physiological aspects. Recent data indicate that the activation of angiotensin-converting enzyme/angiotensin II/AT1 receptor axis facilitates the emotional stress responses. On the other hand, growing evidence indicates that its counterregulatory axis, the angiotensin-converting enzyme 2 (ACE2)/(Ang)iotensin-(1-7)/Mas axis, reduces anxiety and attenuates the physiological responses to emotional stress. The present review focuses on angiotensin-(1-7)/Mas axis as a promising target to attenuate the physiological response to emotional stress reducing the risk of cardiovascular diseases.

Propranolol for the treatment of anxiety disorders: Systematic review and meta-analysis

The effects of propranolol in the treatment of anxiety disorders have not been systematically evaluated previously. The aim was to conduct a systematic review and meta-analysis of randomised controlled trials, addressing the efficacy of oral propranolol versus placebo or other medication as a treatment for alleviating either state or trait anxiety in patients suffering from anxiety disorders. Eight studies met the inclusion criteria. These studies concerned panic disorder with or without agoraphobia (four studies, total n = 130), specific phobia (two studies, total n = 37), social phobia (one study, n = 16), and posttraumatic stress disorder (PTSD) (one study, n = 19). Three out of four panic disorder trials qualified for pooled analyses. These meta-analyses found no statistically significant differences between the efficacy of propranolol and benzodiazepines regarding the short-term treatment of panic disorder with or without agoraphobia. Also, no evidence was found for effects of propranolol on PTSD symptom severity through inhibition of memory reconsolidation. In conclusion, the quality of evidence for the efficacy of propranolol at present is insufficient to support the routine use of propranolol in the treatment of any of the anxiety disorders.

Can Interoception Improve the Pragmatic Search for Biomarkers in Psychiatry?

Disrupted interoception is a prominent feature of the diagnostic classification of several psychiatric disorders. However, progress in understanding the interoceptive basis of these disorders has been incremental, and the application of interoception in clinical treatment is currently limited to panic disorder. To examine the degree to which the scientific community has recognized interoception as a construct of interest, we identified and individually screened all articles published in the English language on interoception and associated root terms in Pubmed, Psychinfo, and ISI Web of Knowledge. This search revealed that interoception is a multifaceted process that is being increasingly studied within the fields of psychiatry, psychology, neuroscience, and biomedical science. To illustrate the multifaceted nature of interoception, we provide a focused review of one of the most commonly studied interoceptive channels, the cardiovascular system, and give a detailed comparison of the most popular methods used to study cardiac interoception. We subsequently review evidence of interoceptive dysfunction in panic disorder, depression, somatic symptom disorders, anorexia nervosa, and bulimia nervosa. For each disorder, we suggest how interoceptive predictions constructed by the brain may erroneously bias individuals to express key symptoms and behaviors, and outline questions that are suitable for the development of neuroscience-based mental health interventions. We conclude that interoception represents a viable avenue for clinical and translational research in psychiatry, with a well-established conceptual framework, a neural basis, measurable biomarkers, interdisciplinary appeal, and transdiagnostic targets for understanding and improving mental health outcomes.

The efficacy and safety of alprazolam versus other benzodiazepines in the treatment of panic disorder

We performed a meta-analysis of all single- or double-blind, randomized controlled trials comparing alprazolam to another benzodiazepine in the treatment of adult patients meeting the Diagnostic and Statistical Manual of Mental Disorders, Third or Fourth Edition, criteria for panic disorder or agoraphobia with panic attacks. Eight studies met inclusion criteria, describing a total of at least 631 randomized patients. In the pooled results, there were no significant differences in efficacy between alprazolam and the comparator benzodiazepines on any of the prespecified outcomes: improvement in mean panic attack frequency (between-arm weighted mean difference of 0.6 panic attacks per week; 95% confidence interval [CI], -0.3 to 1.6), improvement in Hamilton Anxiety Rating Scale score (weighted mean difference of 0.8 points; 95% CI, -0.5 to 2.1), and proportion of patients free of panic attacks at the final evaluation (pooled relative risk, 1.1; 95% CI, 0.9-1.4). Statistical heterogeneity on prespecified outcomes was not eliminated by stratification on baseline anxiety level. The available evidence fails to demonstrate alprazolam as superior to other benzodiazepines for the treatment of panic disorder.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for the pharmacological treatment of anxiety, obsessive-compulsive and post-traumatic stress disorders - first revision

In this report, which is an update of a guideline published in 2002 (Bandelow et al. 2002, World J Biol Psychiatry 3:171), recommendations for the pharmacological treatment of anxiety disorder, obsessive-compulsive disorder (OCD) and post-traumatic stress disorder (PTSD) are presented. Since the publication of the first version of this guideline, a substantial number of new randomized controlled studies of anxiolytics have been published. In particular, more relapse prevention studies are now available that show sustained efficacy of anxiolytic drugs. The recommendations, developed by the World Federation of Societies of Biological Psychiatry (WFSBP) Task Force for the Pharmacological Treatment of Anxiety, Obsessive-Compulsive and Post-traumatic Stress Disorders, a consensus panel of 30 international experts, are now based on 510 published randomized, placebo- or comparator-controlled clinical studies (RCTs) and 130 open studies and case reports. First-line treatments for these disorders are selective serotonin reuptake inhibitors (SSRIs), serotonin-noradrenaline reuptake inhibitors (SNRIs) and the calcium channel modulator pregabalin. Tricyclic antidepressants (TCAs) are equally effective for some disorders, but many are less well tolerated than the SSRIs/SNRIs. In treatment-resistant cases, benzodiazepines may be used when the patient does not have a history of substance abuse disorders. Potential treatment options for patients unresponsive to standard treatments are described in this overview. Although these guidelines focus on medications, non-pharmacological were also considered. Cognitive behavioural therapy (CBT) and other variants of behaviour therapy have been sufficiently investigated in controlled studies in patients with anxiety disorders, OCD, and PTSD to support them being recommended either alone or in combination with the above medicines.

Combined psychotherapy plus benzodiazepines for panic disorder

BACKGROUND

The efficacy of combining psychotherapy and benzodiazepines for panic disorder is unclear, despite widespread use.

OBJECTIVES

To examine the efficacy of the combination compared with either treatment alone.

SEARCH STRATEGY

Randomised trials comparing the combination of psychotherapy and benzodiazepine with either therapy alone for panic disorder were identified. The Cochrane Depression, Anxiety and Neurosis Group Studies and References Registers were searched. References of relevant trials and other reviews were checked. Experts in the field were contacted. Additional unpublished data were sought from authors of the original trials.

SELECTION CRITERIA

Two authors independently checked the records retrieved by the searches to identify randomised trials comparing the combined therapy versus either of the monotherapies, among adults with panic disorder.

DATA COLLECTION AND ANALYSIS

Two authors independently checked eligibility, assessed quality and extracted data from the eligible trials using a standardised data extraction form. The primary outcome was "response" based on global judgement. Random-effects meta-analyses were conducted, combining data from included trials.

MAIN RESULTS

Three trials met eligibility criteria. A 16-week behaviour therapy intervention was used in two trials, and a 12-week cognitive-behaviour therapy intervention in the third. Duration of follow-up varied, ranging from 0 to 12 months. Two trials (total 166 participants) provided data comparing combination with psychotherapy alone (both using behaviour therapy). No statistically significant differences were observed in response during the intervention (relative risk (RR) for combination 1.25, 95% CI 0.78 to 2.03, P = 0.35), at the end of the intervention (RR 0.78, 0.45 to 1.35, P = 0.37), or at the last follow-up time point, although the follow-up data suggested that the combination might be inferior to behaviour therapy alone (RR 0.62, 0.36 to 1.07, P = 0.08). One trial (77 participants) compared combination with a benzodiazepine alone. No differences were found in response during the intervention (RR 1.57, 0.83 to 2.98, P = 0.17). Although the combination appeared to be superior to the benzodiazepine alone at the end of treatment (RR 3.39, 1.03 to 11.21, P = 0.05) the finding was only borderline statistically significant, and no significant differences were observed at the 7-month follow-up (RR 2.31, 0.79 to 6.74, P = 0.12).

AUTHORS' CONCLUSIONS

The review established the paucity of high quality evidence investigating the efficacy of psychotherapy combined with benzodiazepines for panic disorder. Currently, there is inadequate evidence to assess the clinical effects of psychotherapy combined with benzodiazepines for patients who are diagnosed with panic disorder.

Combination of psychotherapy and benzodiazepines versus either therapy alone for panic disorder: a systematic review

BACKGROUND

The efficacy of combined psychotherapy and benzodiazepine treatment for panic disorder is still unclear despite its widespread use. The present systematic review aims to examine its efficacy compared with either monotherapy alone.

METHODS

All randomised trials comparing combined psychotherapy and benzodiazepine for panic disorder with either therapy alone were identified by comprehensive electronic search on the Cochrane Registers, by checking references of relevant studies and of other reviews, and by contacting experts in the field. Two reviewers independently checked eligibility of trials, assessed quality of trials and extracted data from eligible trials using a standardized data extraction form. Our primary outcome was "response" defined by global judgement. Authors of the original trials were contacted for further unpublished data. Meta-analyses were undertaken synthesizing data from all relevant trials.

RESULTS

Only two studies, which compared the combination with behaviour (exposure) therapy, met our eligibility criteria. Both studies had a 16-week intervention. Unpublished data were retrieved for one study. The relative risk for response for the combination was 1.25 (95%CI: 0.78 to 2.03) during acute phase treatment, 0.78 (0.45 to 1.35) at the end of treatment, and 0.62 (0.36 to 1.07) at 6-12 months follow-up. Some secondary outcomes hinted at superiority of the combination during acute phase treatment. One study was identified comparing the combination to benzodiazepine. The relative risk for response was 1.57 (0.83 to 2.98), 3.39 (1.03 to 11.21, statistically significant) and 2.31 (0.79 to 6.74) respectively. The superiority of the combination was observed on secondary outcomes at all the time points. No sub-group analyses were conducted due to the limited number of included trials.

CONCLUSION

Unlike some narrative reviews in the literature, our systematic search established the paucity of high quality evidence for or against the combined psychotherapy plus benzodiazepine therapy for panic disorder. Based on limited available published and unpublished data, however, the combined therapy is probably to be recommended over benzodiazepine alone for panic disorder with agoraphobia. The combination might be superior to behaviour therapy alone during the acute phase, but afterwards this trend may be reversed. We know little from these trials about their adverse effects.

Panic disorder

Panic disorder is a common mental disorder that affects up to 5% of the population at some point in life. It is often disabling, especially when complicated by agoraphobia, and is associated with substantial functional morbidity and reduced quality of life. The disorder is also costly for individuals and society, as shown by increased use of health care, absenteeism, and reduced workplace productivity. Some physical illnesses (eg, asthma) commonly occur with panic disorder, and certain lifestyle factors (eg, smoking) increase the risk for the disorder, but causal pathways are still unclear. Genetic and early experiential susceptibility factors also exist, but their exact nature and pathophysiological mechanisms remain unknown. Despite an imprecise, although increased, understanding of cause, strong evidence supports the use of several effective treatments (eg, pharmacological, cognitive-behavioural). The adaptation and dissemination of these treatments to the frontlines of medical-care delivery should be urgent goals for the public-health community.

Power spectrum analysis and cardiovascular morbidity in anxiety disorders

Spectral analysis of heart rate variability (HRV) and related measures has been shown to be a reliable noninvasive technique enabling quantitative assessment of cardiovascular autonomic regulatory responses to autonomic regulatory mechanisms; it provides a dynamic probe of sympathetic and parasympathetic tone, reflecting the interactions between the two. Over 20 studies reported abnormalities of HRV in anxiety, and patients with heart disease and anxiety are at increased risk for morbidity and mortality. Psychiatric drugs partly correct abnormalities of HRV and, recently, autonomic drugs (beta-blockers) have been studied in anxiety disorders. The authors call for further studies, especially in patients with co-existing anxiety disorders and heart disease, incorporating assessment of HRV.

Benzodiazepines and anxiety disorders: a review for the practicing physician

OBJECTIVES AND SCOPE: The objective of this article is to briefly review for practicing clinicians differences among the benzodiazepines (BZDs) that are commonly used to treat anxiety, the efficacy of BZDs in various anxiety disorders, and potential safety issues associated with BZDs, including adverse events, tolerance, dependence, and withdrawal.

METHODOLOGY

Information for this review was obtained using literature searches through PubMed (1966-2004), Google, and the Food and Drug Administration Catalog of Approved Drugs. Data sources were searched for information regarding anxiety disorders and the safety and efficacy of BZDs. Wherever possible and appropriate, information from randomized controlled trials was given priority.

FINDINGS

Benzodiazepines have demonstrated efficacy in treating patients with anxiety disorders, with varying degrees of efficacy. Use of BZDs is advantageous because they have a quick onset of action and are generally well tolerated. Extended-release formulations of BZDs may be particularly advantageous in some patients with anxiety as they allow for maximization of a drug's therapeutic window with consistent serum drug concentrations.

CONCLUSIONS

BZDs remain a mainstay in the treatment of anxiety, as both monotherapy and adjunctive therapy. Factors to consider prior to prescribing a BZD include the patient's diagnosis, as well as drug characteristics, including the potential for interactions with other drugs, the risk of dependence and withdrawal, and the required frequency of dosing.

Treatment-resistant panic disorder

A substantial number of patients with panic disorder and agoraphobia may remain symptomatic after standard treatment (including selective serotonin reuptake inhibitors, tricyclic antidepressants, benzodiazepines, or irreversible monamine oxidase inhibitors). In this review, recommendations for the treatment of patients with panic disorder and agoraphobia who do not respond to these drugs are provided. Nonresponse to drug treatment could be defined as a failure to achieve a 50% reduction on a standard rating scale after a minimum of 6 weeks of treatment in adequate dose. When initial treatments have failed, the medication should be changed to other standard treatments. In further attempts at treatment, drugs should be used that have shown promising results in preliminary studies, such as venlafaxine. Combination treatments may be used, such as the combination of an selective serotonin reuptake inhibitor and a benzodiazepine. Psychological treatments such as cognitive-behavioral therapy have to be considered in all patients, regardless whether they are nonresponders or not. According to existing studies, a combination of pharmacologic treatment with cognitive-behavioral therapy can be recommended.

Personality disorder and social anxiety predict delayed response in drug and behavioral treatment of panic disorder

BACKGROUND

The aim of this study was to analyze the impact of pretreatment characteristics and personality disorders on the onset of response in the treatment of panic disorder.

METHODS

The data of 73 out-patients with panic disorder who had completed at least 6 weeks of a randomized trial of 24 weeks of either paroxetine only or paroxetine combined with cognitive group-therapy were analyzed in a Cox proportional hazards model.

RESULTS

The likelihood of having responded to treatment (defined by a CGI rating of improvement) was more than twice as high for patients without a personality disorder or social phobia than for Patients with a personality disorder or social phobia.

CONCLUSIONS

We suggest that patients with these characteristics do benefit from prolonged treatment, and they may profit from an additional treatment focused on social anxiety.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for the pharmacological treatment of anxiety, obsessive-compulsive and posttraumatic stress disorders

In this report, recommendations for the pharmacological treatment of anxiety and obsessive-compulsive disorders are presented, based on available randomized, placebo- or comparator-controlled clinical studies. Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for panic disorder. Tri2-cyclic antidepressants (TCAs) are equally effective, but they are less well tolerated than the SSRIs. In treatment-resistant cases, benzodiazepines like alprazolam may be used when the patient does not have a history of dependency and tolerance. Due to possible serious side effects and interactions with other drugs and food components, the irreversible monamine oxidase inhibitor (MAOI) phenelzine should be used only when first-line drugs have failed. In generalised anxiety disorder, venlafaxine and SSRIs can be recommended, while buspirone and imipramine may be alternatives. For social phobia, SSRIs are recommended for the first line, and MAOIs, moclobemide and benzodiazepines as second line. Obsessive-compulsive disorder is best treated with SSRIs or clomipramine.

The psychobiology of anxiolytic drugs. Part 1: Basic neurobiology

The authors provide an overview of the current state of knowledge with regards to the neurobiological mechanisms involved in normal and pathological anxiety. A brief review of the classification and cognitive psychology of anxiety is followed by a more in-depth look at the neuroanatomical and neurochemical processes and their relevance to our understanding of the modes of action of anxiolytic drugs. The serotonergic, noradrenergic, and gamma-aminobutyric acidergic systems are reviewed. The numerous physiological and pharmacological methods of anxiety provocation and the increasing importance of functional neuroimaging are also examined. The review provides an overview of the biology and basic pharmacology of anxiolytic drugs, and compliments the more clinically oriented companion review.

The use of benzodiazepines in anxiety and other disorders

Benzodiazepines have come under scrutiny and attack over recent years because of their abuse liability, withdrawal reactions and development of tolerance. Consequently, practitioners worldwide are discouraged from prescribing them. While some of these risks may have been exaggerated, benzodiazepines remain a useful therapeutic tool, alone or in combination, in a number of psychiatric and medical conditions. Withholding such treatment may be unjustified and detrimental to the patients' health. Further, benzodiazepines have helped researchers in their attempts to elucidate the neurobiological mechanisms underlying anxiety. This, in return, leads to the development of new effective anxiolytic treatments, with fewer problems compared to the traditional benzodiazepine compounds. Such new agents are already available or at the closing stages of clinical trials.

Generalized anxiety disorder and its comorbidities: disputes at the boundaries

This theoretical paper reviews the status of generalized anxiety disorder (GAD) and the Axis I and Axis II disorders with which it is often comorbid. Differences in comorbidity between the epidemiological and clinical literatures are discussed. Special attention is given to panic disorder, the symptoms of which are similar to those of GAD. The boundaries of GAD and its relationship to other Axis I disorders and to Axis II disorders raise important implications for its classification.

Clonazepam in the treatment of panic disorder with or without agoraphobia: a dose-response study of efficacy, safety, and discontinuance. Clonazepam Panic Disorder Dose-Response Study Group

In this multicenter, parallel-group, placebo-controlled, fixed-dose study, the efficacy, safety, dosing characteristics, and discontinuation of clonazepam were analyzed in patients with panic disorder. Four hundred thirteen patients were randomly assigned to receive placebo or one of five fixed daily doses of clonazepam (0.5 mg, 1.0 mg, 2.0 mg, 3.0 mg, and 4.0 mg). After 3 weeks of dose escalation, the fixed dose was given for 6 weeks (the dose-maintenance phase) and then was tapered during a 7-week discontinuance phase. The completion rates for the dose-maintenance phase ranged from 59 to 85% for the clonazepam groups (74% for the placebo group). Efficacy measurements at the end of the dose-maintenance phase indicated clinical improvement in all treatment groups but with a clear differentiation of the four higher doses of clonazepam from the 0.5-mg dose and placebo. The minimum effective dosage, as determined by the Williams' test, was 1.0 mg daily. Dose-response analysis showed that daily dosages of 1.0 mg and higher were equally efficacious in reducing the number of panic attacks. All treatments were well tolerated. Somnolence and ataxia were reported more often by patients in the 3.0- and 4.0-mg groups; depression, dizziness, fatigue, and irritability, although not showing dose-relatedness, were reported by more patients taking clonazepam than placebo. During the discontinuance phase, most patients worsened from their condition at the end of the dose-maintenance phase but did not revert to that at baseline. In addition, with the tapering schedule chosen for this study, patients in all treatment groups tolerated the discontinuance of clonazepam. Daily doses of 1.0 to 2.0 mg of clonazepam offered the best balance of therapeutic benefit and tolerability.

The treatment of anxiety disorders: a legacy of William Sargant

In 1962 William Sargant and his colleagues described the therapeutic value of phenelzine, a monoamine oxidase inhibitor (MAOI), in chronic anxiety disorders and in the same year Klein and Fink reported the treatment of similar conditions with imipramine, a tricyclic antidepressant. Subsequent research has confirmed these findings and demonstrated the range of similar drugs that are effective in anxiety disorders. At the time of these original observations about the drug treatment of anxiety, there were no psychological treatments of proven value but in the intervening years much progress has been made in developing behavioural and cognitive procedures. The progress in determining the mode of action of these pharmacological and psychological treatments is reviewed and the implications of the findings are considered in relation to research into the causes of the anxiety disorders and to the treatment of patients.

Description of antipanic therapy in a prospective longitudinal study

The authors present a summary scale for assessing the percentage of patients in a large longitudinal study of panic disorder who received proven effective psychopharmacologic treatment. Such a scale provides a means for assessing and comparing somatic treatments of panic disorder across medication classes. The antipanic therapy levels were applied to data on medication treatment received by 492 patients participating in a naturalistic study and reflect psychopharmacologic treatment prescribed in 11 academic centers. Results show that among patients treated by psychiatrists at major teaching hospitals only 54% of the most symptomatic groups received optimal pharmacologic treatment. Among less symptomatic patients, who nonetheless met full criteria for panic disorder with or without agoraphobia, only 43% received maximal therapy.

Effects of intravenous diazepam pretreatment on lactate-induced panic

The psychological and physiological effects of acute low-potency benzodiazepine administration on lactate-induced panic were examined in 10 patients with panic disorder (PD). The patients, who had panicked during a standard sodium-lactate infusion, underwent a repeat infusion modified by pretreatment with intravenous diazepam (5 mg). Acute Panic Inventory (API) scores preceding the second lactate infusion, which were associated with diazepam pretreatment, were significantly reduced in compared with those measured before the first lactate infusion. However, the second visit "fear of doom" item of the API was significantly reduced relative to the same time point of the first visit 35 min before lactate infusion, when diazepam had not yet been administered. Thus, the reduction of prelactate anxiety preceding the second infusion appeared to reflect both pharmacological and nonpharmacological contributions. The diazepam pretreatment condition was associated with a significantly increased infusion duration and a significant attenuation of rate of API symptom increase in response to lactate. Despite significant attenuation of lactate infusion effects associated with the diazepam pretreatment condition, 7 of 10 patients experienced a second panic attack. This pilot study suggests that diazepam pretreatment is associated with a marked reduction of symptomatic response during a second lactate infusion, although the magnitude of attenuation observed was insufficient to block lactate-induced panic in a majority of lactate-vulnerable PD patients.

Panic disorder. Pathophysiology and drug treatment

Advances over the past 2 decades in our understanding of the biology of panic disorder have paralleled a remarkable increase in the development of new pharmacological agents with antipanic effects. Although we can not presently use biological tests to help with our choice of therapeutic agent for individual patients, we can use this biological understanding in the development of overall pharmaco-therapeutic strategies. Current evidence does not support the hypothesis that panic disorder is associated with a primary disorder in one neurotransmitter system. Rather, the data suggest that the biological aetiology of panic disorder is related to abnormalities in the function of a variety of neurotransmitters including serotonin (5-hydroxytyrptamine; 5-HT), noradrenaline (norepinephrine), gamma-aminobutyric acid (GABA), dopamine, and cholecystokinin. It is likely, however, that panic disorder is a biologically heterogeneous condition and that biological subtypes may exist in which the primary abnormality may involve one or a few neurotransmitter systems. Currently, the data best support the hypothesis that pharmacotherapeutic agents with primary action at sites within the GABA and serotonin systems are the most effective in the treatment of panic disorder. Nevertheless, some patients will respond well to drugs with predominant activity in other systems, or may require pharmacotherapy designed to affect the function of more than 1 neurotransmitter. As our understanding of the biological aetiology of panic disorder evolves, the pharmacotherapeutic agents and strategies used in the treatment of this disorder will continue to evolve as well.

Conditioned ultrasonic distress vocalizations in adult male rats as a behavioural paradigm for screening anti-panic drugs

Rats may produce ultrasonic vocalizations (USV) in threatening situations. USV of adult male rats in association with aversive stimulation was evaluated as a screening method for anxiolytic drugs. The triazolobenzodiazepine alprazolam, the 5-HT uptake inhibitors fluvoxamine and clomipramine, the mixed 5-HT/NA uptake inhibitor imipramine, the full 5-HT1A receptor agonists 8-OH-DPAT and flesinoxan, the partial 5-HT1A receptor agonists buspirone, ipsapirone and BMY 7378, the alpha 2-adrenoceptor agonist clonidine and the alpha 2-adrenoceptor antagonist yohimbine reduced conditioned USV. The classical benzodiazepines (BZD) diazepam and chlordiazepoxide were ineffective or had a very low potency to decrease USV. The partial BZD receptor agonists bretazenil, alpidem and zolpidem, the BZD receptor antagonist flumazenil, the NA uptake inhibitors desipramine and maprotiline, and the 5-HT3 receptor antagonist ondansetron had no effect on conditioned USV. The dopamine-D2 receptor antagonist haloperidol reduced USV at a very high dose. In separate experiments the effects of these drugs on locomotor activity were assessed. There was, however, no direct relationship between effects on motor behaviour and USV. In conclusion, the sensitivity of conditioned USV to 5-HT uptake inhibitors and alprazolam versus the insensitivity to classical benzodiazepines and NA uptake inhibitors provides a very interesting profile, which closely resembles the psychopharmacology of panic disorder. Also the face validity of conditioned USV towards situational panic attacks is high. We therefore propose conditioned USV in adult male rats as a novel behavioural paradigm to screen for anti-panic drugs.

Predictors of short-term treatment response in 66 patients with panic disorder

Short-term treatment response in panic disorder was studies in 66 subjects who had completed 3 weeks of treatment with fluvoxamine (n = 23), cognitive therapy (n = 20), or placebo (n = 23). Clinical and self-rated assessments were gathered at baseline, during, and after treatment. Using multiple logistic regression, treatment with fluvoxamine, a low panic attack severity score, and absence of a comorbid personality disorder were identified as significant predictors of recovery. Personality disorder was an important negative predictor to outcome with cognitive therapy. The results support the efficacy of fluvoxamine, and show that patients with low symptom severity and a normal personality respond well to treatment.

Pre-treatment predictors of treatment outcome in panic disorder and agoraphobia treated with alprazolam and exposure

Pre-treatment predictors of treatment outcome were examined in a group of 144 patients with panic disorder and agoraphobia randomly allocated to alprazolam+exposure (AE), placebo+exposure (PE), alprazolam+relaxation (AR), and placebo+relaxation (PR). First-time psychotropic medication use, severity of agoraphobic disability, and longer duration of illness predicted less global improvement at post-treatment. Pre-treatment severity of agoraphobia predicted less improvement both in the short- and the long-term. Predictors of poorer outcome at 6-month follow-up were older age, past history of depression, severity of phobia targets, and longer duration of illness. Sex, source of referral, pre-treatment depression-anxiety-panic, and expectancy from treatment did not relate to outcome.

Lactate-induced anxiety after imipramine and diazepam treatment

To examine the effect of treatment on lactate-induced anxiety in a controlled study, we infused 44 panic disorder patients with lactate and placebo before and after eight weeks of double-blind treatment with imipramine, diazepam, or placebo. During treatment, both imipramine and diazepam groups improved more than the placebo group. After treatment, patients in both the imipramine and diazepam groups had significantly less anxiety than the placebo patients when reinfused with lactate. In addition, imipramine decreased posttreatment panic attack frequency and diazepam decreased the perceived severity of posttreatment lactate-induced panic attacks. This study demonstrates that diazepam, like imipramine, is an effective treatment for panic disorder, and that both imipramine and diazepam blunt lactate-induced anxiety in a placebo controlled study.

Predictors of response to alprazolam and placebo in patients with panic disorder

Date from a panic disorder treatment study with 506 patients, comparing alprazolam and placebo in a double-blind manner for 8 weeks, were analyzed to identify demographic and clinical characteristics of the patients that might predict response to treatment. The strongest predictors of response to alprazolam were age over 40, and lower baseline levels of anxiety and phobic symptoms. Predictors of response to placebo were weaker and, in addition to lower levels anxiety and panic attacks, included a lack of previous psychiatric treatment.

The use of antidepressant drugs in general practice. A questionnaire survey

The aim of this study was to examine the anti-depressant drug prescribing preferences and habits of a population of general practitioners. The method used was that of a questionnaire survey, including case vignettes. The response rate exceeded 70% Data are presented out-lining the attitudes of the respondents to the use of antidepressant drugs in the management of common psychiatric presentations in the primary care setting. The majority of general practitioners (G.P.'s) had received little or no post-graduate education in psychiatry. The antidepressants most frequently prescribed were amitriptyline, clomipramine, trazodone and lofepramine. Despite recognition of the alarming frequency of serious self-poisoning incidents with some of these compounds, 26% of respondents confessed to an inability to make an informed choice of antidepressant drug, with 14% using the same drug with every patient with no attempt to select according to individual patient requirements. The management of depressive neurosis generates considerable clinical confusion with a variety of interventions favoured. The use of a sedating antidepressant is popular. There is greater accord for the management of endogenomorphic depression. The use of the benzodiazepine drugs in the management of anxiety disorders is infrequent, with appropriate recognition of the merits of behavioural approaches. However, the role for antidepressant drugs in the management of anxiety disorders is under-recognized. We conclude that general practitioners are required to undertake a significant body of work for which they may be inadequately trained.

The relative efficacy of high-dose buspirone and alprazolam in the treatment of panic disorder: a double-blind placebo-controlled study

This 8-week double-blind placebo-controlled trial investigated the relative efficacy and safety of alprazolam and buspirone in the treatment of panic disorder. Alprazolam (mean +/- SD dose 5.2 +/- 2.6 mg) produced a rapid and sustained improvement in panic attacks, anxiety, phobias, and disability and was superior to buspirone (mean +/- SD dose 61 +/- 26.5 mg) and placebo on all of these measures on completer (n = 85) and endpoint analysis (n = 92). Although higher doses of buspirone were used in this study than in previous trials, buspirone was not superior to placebo on any of the outcome measures. The results were disappointing in light of buspirone's benign side effect profile and low abuse potential.

Long-term drug treatment of panic disorder

Drug treatment of panic disorder with benzodiazepines and antidepressants has been established as efficacious in the short-term (6-8 weeks). The efficacy of medications during long-term (i.e., continuous) treatment has not often been addressed and a review of the evidence is presented. Most data exists for the long-term effectiveness of benzodiazepines. Experience with the triazolobenzodiazepine, alprazolam, is reviewed together with some other high potency drugs, e.g., clonazepam. Tricyclic antidepressants are also effective in the long-term treatment of panic and the relevant studies are presented. Long-term efficacy for monoamine oxidase inhibitors is not as clearly established. The issue of relapse following drug withdrawal is addressed and some strategies for patient management in long-term therapy are discussed.

Benzodiazepine treatment of panic and agoraphobic symptoms: use, dependence, toxicity, abuse

Benzodiazepines are widely prescribed drugs. Most patients are prescribed benzodiazepines for short periods of time for anxiolytic or hypnotic purposes. However, some benzodiazepines are also used for extended periods at high doses to treat panic and agoraphobic disorders. When chronically prescribed benzodiazepines are discontinued, a predictable pattern of discontinuance symptoms may develop, indicating physiological dependence. Benzodiazepines also produce a variety of side effects including sedation, reduced coordination, and impaired cognition, which are primarily related to dose and duration of treatment. Benzodiazepines are commonly used by polysubstance abusers but their abuse as recreational drugs when taken alone is rare, and high-dose treatment for panic and agoraphobic symptoms does not lead to abuse. Prescribing guidelines are offered.

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.

Panic attacks. A neurochemical overview of models and mechanisms

The delineation of panic disorder as a distinct diagnostic entity has provided renewed impetus for research into panic. This review describes and examines the range of neurobiological theories of panic attacks. It illustrates the diversity of mechanisms that have been invoked to explain the production of panic attacks, and which have influenced much of the current thinking about the neurochemistry of anxiety.

Drug treatment of panic disorder. Comparative efficacy of alprazolam, imipramine, and placebo. Cross-National Collaborative Panic Study, Second Phase Investigators

The Cross-National Collaborative Panic Study, Phase Two, compared alprazolam with imipramine and with placebo in a sample of 1168 randomly assigned subjects. The study, conducted at 12 centres, assessed clinical change over eight weeks of double-blind drug treatment. Improvement occurred with alprazolam by week 1 and 2, and with imipramine by week 4. By the end of week 8, however, the effects of the two active drugs were similar to each other, and both were superior to placebo for most outcome measures.

Noradrenergic function in panic disorder. Effects of intravenous clonidine pretreatment on lactate induced panic

To assess the role of noradrenergic stimulation during lactate-induced panic, ten patients with panic disorder who panicked during a standard sodium-lactate infusion underwent a repeat infusion following intravenous clonidine pretreatment. Although clonidine significantly lowered prelactate systolic blood pressure, the drug did not significantly lower prelactate anxiety levels, as reflected by the Acute Panic Inventory (API). Clonidine blocked lactate-induced panic in four of ten subjects, a significant effect. Clonidine treatment also significantly attenuated lactate-panic symptoms, as reflected by time to panic and API comparison between trials. Nevertheless, over half the subjects still panicked in response to lactate despite clonidine. This preliminary study suggests that reduction of central noradrenergic activity by clonidine, at least at the dosage levels employed in the current study, only partially attenuates panic response to lactate. Noradrenergic theories of panic may not therefore fully account for lactate panicogenesis.

Anxiolytics not acting at the benzodiazepine receptor: beta blockers

1. Although there is clear evidence for many controlled trials in the past 25 years that beta blockers are effective in anxiety disorders clear indications for their use are lacking. 2. The balance of evidence suggests that the mechanism of action of beta-blocking drugs is through peripheral blockade of beta-mediated symptoms. 3. Most evidence to the efficacy of beta-blockers comes from study of their use in generalized anxiety and in acute stress. 4. Because beta-blockers carry no risks of pharmacological dependence they may be preferred to many other anti-anxiety drugs.

Anxiety, depression, and substance use disorders: diagnosis, treatment, and prescribing practices

Attending physicians routinely encounter patients with signs and symptoms of anxiety and mood disorders as well as psychoactive substance use and psychoactive substance-induced organic mental disorders. These symptoms may represent either primary disorders or pathology that is secondary to other disorders. This article describes some of the relationships between substance use disorders and symptoms of anxiety and depressive disorders. In addition, some patients with these disorders may have a concurrent substance use disorder or be at high risk for developing one. Routine treatment of anxiety disorders with psychoactive drugs can be successful in many patients but may lead to iatrogenic dependence in high-risk patients. Prescribing for high-risk patients should include a stepwise treatment protocol having three progressive levels: (1) conservative, nonpharmacological approaches; (2) nonpsychoactive pharmacotherapy, including the use of anxioselective agents, such as buspirone; and (3) psychoactive pharmacotherapy, such as the use of benzodiazepines. Proper prescribing practices for high-risk patients are described in terms of diagnosis, dosage, duration, discontinuation, dependence, and documentation.

Imipramine in panic disorder. 1. Clinical response and pharmacological changes

Clinical and biochemical variables were monitored in 18 patients with panic disorder before and during treatment with imipramine over 16 weeks. Imipramine dosage was slowly increased from a starting dose of 10 mg daily, to prevent early treatment drop-outs. All patients were effectively treated for at least 6 weeks, and only two patients dropped out before the end of the study. There were substantial reductions in panic attack frequency, ratings of depression and avoidance behaviour, but only small reductions in ratings of state and general anxiety. Plasma levels of the noradrenaline metabolite 3-methoxy-4-hydroxyphenyl- ethylene glycol initially fell after starting imipramine, but returned to pre-treatment levels by week 8 of treatment. Plasma imipramine and/or desipramine concentrations were very variable and did not correlate with either psychological or biochemical changes during treatment.

Behavioral effects of chronic imipramine treatment in genetically nervous pointer dogs

The genetically nervous pointer dog has been proposed as a model for human anxiety disorders. In a double-blind placebo-controlled study, seventeen nervous pointer dogs were treated for four weeks with imipramine hydrochloride (10 mg/kg), a potent antipanic agent in humans. Although three of the dogs demonstrated marked improvement to imipramine but not placebo treatment after short-term administration, chronic imipramine failed to modify the aberrant behavior in any of the dogs. These findings are discussed in the context of the nervous pointer dog as a model for human anxiety disorders.

Acute and chronic effects of propranolol on extinction of rewarded running in the rat

Three experiments examined the effect of propranolol injected IP on a series of 16 extinction trials at 24-hour intertrial intervals after continuously rewarded running. In Experiment I, propranolol (1, 5 or 10 mg/kg) was injected, in different groups, shortly before or shortly after each extinction trial, but without effect. In Experiment II, the same doses were injected daily for 18 days preceding extinction, to allow longer for any long-term drug effect to accumulate. Propranolol (1 mg/kg) facilitated extinction. In Experiment III, a single dose (7.5 mg/kg) was injected before or after extinction trials as in Experiment I; the acute effect was to impair extinction. These results are consistent with previous findings in the Skinner box that propranolol has an acute disinhibitory effect on nonrewarded responses and a long-term inhibitory one. These effects have different dose-response relationships.

Alcoholism and panic disorder: is the comorbidity more than coincidence?

Studies on alcoholic patients have found a higher than expected prevalence of panic disorder, and suggest a positive correlation between the level of alcohol consumption and severity of anxiety. Conversely, there is an increased prevalence of alcoholism among patients with panic disorder and their blood relatives. A comparison of symptoms, physiological and neurochemical changes known to occur in both alcohol withdrawal and panic disorder reveals a degree of similarity between the 2 conditions. Based on the data, we propose that the chemical and cognitive changes occurring as the result of repeated alcohol withdrawals may kindle and condition coincidence of panic attacks in susceptible individuals. Implications of our postulates for treatment of alcohol withdrawal and panic disorder in alcoholics and for future studies are discussed.

Efficacy of benzodiazepines in panic disorder and agoraphobia

Until recently, the benzodiazepines were believed to be ineffective in the treatment of panic disorder, with and without agoraphobic avoidance. Recent trials have shown, however, that panic disorder patients respond to benzodiazepines as well as to tricyclic antidepressants and monoamine oxidase (MAO) inhibitor antidepressants. Most of the controlled-trial investigations of benzodiazepines in panic disorder patients have evaluated the effects of alprazolam. However, early uncontrolled trials using other benzodiazepines have documented their effectiveness in panic disorder as well. This article reviews the evidence of the efficacy of alprazolam and other benzodiazepines in the treatment of panic disorder and their clinical use.