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

Pharmacological treatments in panic disorder in adults: a network meta-analysis

BACKGROUND

A panic attack is a discrete period of fear or anxiety that has a rapid onset and reaches a peak within 10 minutes. The main symptoms involve bodily systems, such as racing heart, chest pain, sweating, shaking, dizziness, flushing, churning stomach, faintness and breathlessness. Other recognised panic attack symptoms involve fearful cognitions, such as the fear of collapse, going mad or dying, and derealisation (the sensation that the world is unreal). Panic disorder is common in the general population with a prevalence of 1% to 4%. The treatment of panic disorder includes psychological and pharmacological interventions, including antidepressants and benzodiazepines.

OBJECTIVES

To compare, via network meta-analysis, individual drugs (antidepressants and benzodiazepines) or placebo in terms of efficacy and acceptability in the acute treatment of panic disorder, with or without agoraphobia. To rank individual active drugs for panic disorder (antidepressants, benzodiazepines and placebo) according to their effectiveness and acceptability. To rank drug classes for panic disorder (selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), mono-amine oxidase inhibitors (MAOIs) and benzodiazepines (BDZs) and placebo) according to their effectiveness and acceptability. To explore heterogeneity and inconsistency between direct and indirect evidence in a network meta-analysis.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Specialised Register, CENTRAL, CDSR, MEDLINE, Ovid Embase and PsycINFO to 26 May 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of people aged 18 years or older of either sex and any ethnicity with clinically diagnosed panic disorder, with or without agoraphobia. We included trials that compared the effectiveness of antidepressants and benzodiazepines with each other or with a placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently screened titles/abstracts and full texts, extracted data and assessed risk of bias. We analysed dichotomous data and continuous data as risk ratios (RRs), mean differences (MD) or standardised mean differences (SMD): response to treatment (i.e. substantial improvement from baseline as defined by the original investigators: dichotomous outcome), total number of dropouts due to any reason (as a proxy measure of treatment acceptability: dichotomous outcome), remission (i.e. satisfactory end state as defined by global judgement of the original investigators: dichotomous outcome), panic symptom scales and global judgement (continuous outcome), frequency of panic attacks (as recorded, for example, by a panic diary; continuous outcome), agoraphobia (dichotomous outcome). We assessed the certainty of evidence using threshold analyses.

MAIN RESULTS

Overall, we included 70 trials in this review. Sample sizes ranged between 5 and 445 participants in each arm, and the total sample size per study ranged from 10 to 1168. Thirty-five studies included sample sizes of over 100 participants. There is evidence from 48 RCTs (N = 10,118) that most medications are more effective in the response outcome than placebo. In particular, diazepam, alprazolam, clonazepam, paroxetine, venlafaxine, clomipramine, fluoxetine and adinazolam showed the strongest effect, with diazepam, alprazolam and clonazepam ranking as the most effective. We found heterogeneity in most of the comparisons, but our threshold analyses suggest that this is unlikely to impact the findings of the network meta-analysis. Results from 64 RCTs (N = 12,310) suggest that most medications are associated with either a reduced or similar risk of dropouts to placebo. Alprazolam and diazepam were associated with a lower dropout rate compared to placebo and were ranked as the most tolerated of all the medications examined. Thirty-two RCTs (N = 8569) were included in the remission outcome. Most medications were more effective than placebo, namely desipramine, fluoxetine, clonazepam, diazepam, fluvoxamine, imipramine, venlafaxine and paroxetine, and their effects were clinically meaningful. Amongst these medications, desipramine and alprazolam were ranked highest. Thirty-five RCTs (N = 8826) are included in the continuous outcome reduction in panic scale scores. Brofaromine, clonazepam and reboxetine had the strongest reductions in panic symptoms compared to placebo, but results were based on either one trial or very small trials. Forty-one RCTs (N = 7853) are included in the frequency of panic attack outcome. Only clonazepam and alprazolam showed a strong reduction in the frequency of panic attacks compared to placebo, and were ranked highest. Twenty-six RCTs (N = 7044) provided data for agoraphobia. The strongest reductions in agoraphobia symptoms were found for citalopram, reboxetine, escitalopram, clomipramine and diazepam, compared to placebo. For the pooled intervention classes, we examined the two primary outcomes (response and dropout). The classes of medication were: SSRIs, SNRIs, TCAs, MAOIs and BDZs. For the response outcome, all classes of medications examined were more effective than placebo. TCAs as a class ranked as the most effective, followed by BDZs and MAOIs. SSRIs as a class ranked fifth on average, while SNRIs were ranked lowest. When we compared classes of medication with each other for the response outcome, we found no difference between classes. Comparisons between MAOIs and TCAs and between BDZs and TCAs also suggested no differences between these medications, but the results were imprecise. For the dropout outcome, BDZs were the only class associated with a lower dropout compared to placebo and were ranked first in terms of tolerability. The other classes did not show any difference in dropouts compared to placebo. In terms of ranking, TCAs are on average second to BDZs, followed by SNRIs, then by SSRIs and lastly by MAOIs. BDZs were associated with lower dropout rates compared to SSRIs, SNRIs and TCAs. The quality of the studies comparing antidepressants with placebo was moderate, while the quality of the studies comparing BDZs with placebo and antidepressants was low.

AUTHORS' CONCLUSIONS

In terms of efficacy, SSRIs, SNRIs (venlafaxine), TCAs, MAOIs and BDZs may be effective, with little difference between classes. However, it is important to note that the reliability of these findings may be limited due to the overall low quality of the studies, with all having unclear or high risk of bias across multiple domains. Within classes, some differences emerged. For example, amongst the SSRIs paroxetine and fluoxetine seem to have stronger evidence of efficacy than sertraline. Benzodiazepines appear to have a small but significant advantage in terms of tolerability (incidence of dropouts) over other classes.

Deprescribing Strategies for Opioids and Benzodiazepines with Emphasis on Concurrent Use: A Scoping Review

While the Food and Drug Administration's black-box warnings caution against concurrent opioid and benzodiazepine (OPI-BZD) use, there is little guidance on how to deprescribe these medications. This scoping review analyzes the available opioid and/or benzodiazepine deprescribing strategies from the PubMed, EMBASE, Web of Science, Scopus, and Cochrane Library databases (01/1995-08/2020) and the gray literature. We identified 39 original research studies (opioids: n = 5, benzodiazepines: n = 31, concurrent use: n = 3) and 26 guidelines (opioids: n = 16, benzodiazepines: n = 11, concurrent use: n = 0). Among the three studies deprescribing concurrent use (success rates of 21-100%), two evaluated a 3-week rehabilitation program, and one assessed a 24-week primary care intervention for veterans. Initial opioid dose deprescribing rates ranged from (1) 10-20%/weekday followed by 2.5-10%/weekday over three weeks to (2) 10-25%/1-4 weeks. Initial benzodiazepine dose deprescribing rates ranged from (1) patient-specific reductions over three weeks to (2) 50% dose reduction for 2-4 weeks, followed by 2-8 weeks of dose maintenance and then a 25% reduction biweekly. Among the 26 guidelines identified, 22 highlighted the risks of co-prescribing OPI-BZD, and 4 provided conflicting recommendations on the OPI-BZD deprescribing sequence. Thirty-five states' websites provided resources for opioid deprescription and three states' websites had benzodiazepine deprescribing recommendations. Further studies are needed to better guide OPI-BZD deprescription.

Pharmacotherapy for Anxiety Disorders: From First-Line Options to Treatment Resistance

In this review, the author examines the evidence for psychopharmacologic treatments among adults for generalized anxiety disorder, panic disorder, and social anxiety disorder derived from clinical trials. For each disorder, major categories of drugs are reviewed, and then the evidence-based medications in each category are discussed. The author reviews key safety and tolerability considerations for each of the medications or classes. Evidence-based dosing for most specific agents is displayed in a comprehensive reference table. Subsequently, the author synthesizes the available information to suggest a pragmatic stepwise approach to treatment that accounts for patient-specific factors. To inform the guidance, the author incorporates and refines perspectives from treatment guidelines already written by clinical professional organizations. The author also briefly reviews the relatively new quantitative systematic review methodology of network meta-analysis (NMA) and discusses how NMA may help guide pharmacologic treatment sequencing decisions in the future by way of ranking treatments according to effect size and the relative amount of study to which treatments have been subject. Caveats of NMA studies are briefly discussed, as are results of recent NMAs regarding the pharmacologic treatment of anxiety disorders.

Comparative efficacy and acceptability of antidepressants and benzodiazepines for the treatment of panic disorder: A systematic review and network meta-analysis

OBJECTIVE

This systematic review aims to assess the efficacy and acceptability of the different types of antidepressants and benzodiazepines for the treatment of panic disorder (PD) in adult patients.

METHODS

PubMed, Web of Science, EMBASE, MEDLINE, the Cochrane Library, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) published between 1995 and 2020 on the use of antidepressants and benzodiazepines for the treatment of PD. A systematic review and network meta-analysis were performed.

RESULTS

42 RCTs were included in the network meta-analysis, with a comparison of 11 interventions.Escitalopram (odds ratios OR 1.52, 95 % credible interval CI 1.09-2.10), venlafaxine (OR 1.33, 95 % CI 1.16-1.51) and benzodiazepines (OR 1.50, 95 % CI 1.29-1.75) had greater efficacy and acceptability than the placebo. Imipramine(OR 1.43, 95 % CI 1.15-1.79) was also demonstrated to be efficacious and tolerated but the results were restricted to small sample size. Moreover, paroxetine, sertraline, fluoxetine, citalopram and clomipramine (OR 1.37, 1.36, 1.45, 1.33 and 1.36, respectively) were more efficacious, although the acceptability of paroxetine and sertraline were significantly less tolerated than benzodiazepines. Notably, the efficacy of reboxetine and fluvoxamine were merely as equal as that of the placebo.

OUTCOMES

This is the first systematic review of antidepressants and benzodiazepines for the treatment of PD to use a network analysis. Escitalopram and venlafaxine as well as benzodiazepines may be effective choices as treatments for PD with relatively good acceptability, which still needs to be confirmed byhigh-quality RCTs.

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.

Benzodiazepines for anxiety disorders: maximising the benefits and minimising the risks

Benzodiazepines still play an important role in the management of anxiety disorders but dependence is associated with their therapeutic use. The key to effective and safe long-term use of benzodiazepines is: the careful selection of patients who might benefit from them; administration in clinical situations in which they are more likely to be beneficial; use of lower doses and in conjunction with an antidepressant, if possible; monitoring and managing their side-effects; and minimising the risk of withdrawal symptoms and relapse, mainly through tapering the dose and/or combining with effective psychological interventions.

A 6-Year Posttreatment Follow-up of Panic Disorder Patients: Treatment With Clonazepam Predicts Lower Recurrence Than Treatment With Paroxetine

BACKGROUND

The aim of this study was to identify factors associated with relapse in panic disorder (PD).

METHODS

This was an observational study conducted in the outpatient clinic of a psychiatric hospital in Rio de Janeiro, Brazil. In a previous study, 120 patients diagnosed as having PD according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria were randomized to receive clonazepam or paroxetine. After 3 years, treatment was discontinued in patients who had achieved remission. These subjects were included in the current study and were followed up for 6 years. The follow-up assessments were made at 1, 2, 3, 5, and 6 years after treatment discontinuation. Assessment included the number of panic attacks per month, Clinical Global Impression-Severity, and other measures. Patients who had initiated psychotherapy or pharmacological treatment because of PD symptoms or who had Clinical Global Impression-Severity scores greater than 1 or panic attacks in the month preceding the assessment were considered relapse cases. Data were collected from January 2003 to August 2012.

RESULTS

Eighty-five patients completed the follow-up. Cumulative relapse rates were 50% (n = 33) at 1 year and 89.4% (n = 76) at 6 years. One-year relapse rates were lower in patients previously treated with clonazepam (P = 0.001) compared with those treated with paroxetine. Low 6-year relapse rates were associated with high Hamilton Anxiety Rating Scale scores before treatment (P = 0.016) and previous treatment with clonazepam.

CONCLUSIONS

Relapse is a frequent problem in PD, and long-term treatment does not protect these patients in the long run. Treatment with clonazepam predicts lower relapse when compared with paroxetine.

Changes in cerebral blood flow after cognitive behavior therapy in patients with panic disorder: a SPECT study

AIM

Inconsistent results continue to be reported in studies that examine the neural correlates of cognitive behavioral therapy (CBT) in patients with panic disorder. We examined the changes in regional cerebral blood flow (rCBF) associated with the alleviation of anxiety by CBT in panic patients.

METHODS

The change in rCBF and clinical symptoms before and after CBT were assessed using single photon emission computed tomography and various clinical measures were analyzed.

RESULTS

Fourteen subjects who completed CBT showed significant improvements in symptoms on clinical measures, including the Panic and Agoraphobic Scale and the Anxiety Sensitivity Index-Revised. After CBT, increased rCBF was detected in the left postcentral gyrus (BA 43), left precentral gyrus (BA 4), and left inferior frontal gyrus (BA 9 and BA 47), whereas decreased rCBF was detected in the left pons. Correlation analysis of the association between the changes in rCBF and changes in each clinical measure did not show significant results.

CONCLUSION

We found changes in the rCBF associated with the successful completion of CBT. The present findings may help clarify the effects of CBT on changes in brain activity in panic disorder.

The role of alprazolam for the treatment of panic disorder in Australia

OBJECTIVE

To investigate the potential impact of increasing prescription rates of alprazolam for the treatment of panic disorder (PD) in Australia through a review of efficacy, tolerability and adverse outcome literature.

METHODS

Data were sourced by a literature search using MEDLINE, Embase, PsycINFO and a manual search of scientific journals to identify relevant articles. Clinical practice guidelines from the American Psychiatric Association, National Institute of Clinical Excellence, Royal Australian and New Zealand College of Psychiatrists and World Federation of Societies of Biological Psychiatry were sourced. Prescription data were sourced from Australian governmental sources.

RESULTS

Alprazolam has shown efficacy for control of PD symptoms, particularly in short-term controlled clinical trials, but is no longer recommended as a first-line pharmacological treatment due to concerns about the risks of developing tolerance, dependence and abuse potential. Almost no evidence is available comparing alprazolam to current first-line pharmacological treatment. Despite this, prescription rates are increasing. A number of potential issues including use in overdose and impact on car accidents are noted. conclusion: Although effective for PD symptoms in clinical trials, a number of potential issues may exist with use. Consideration of its future place in PD treatment in Australia may be warranted.

Controlled clinical, polysomnographic and psychometric studies on differences between sleep bruxers and controls and acute effects of clonazepam as compared with placebo

The pathogenesis, pathophysiology, and pharmacotherapy of sleep bruxism (SB) are still not fully understood. We investigated symptomatology, objective and subjective sleep and awakening quality of middle-aged bruxers compared with controls and acute effects of clonazepam 1 mg compared with placebo by polysomnography and psychometry. Twenty-one drug-free bruxers spent 3 nights in the sleep lab, 21 age- and sex-matched controls 2 nights. Clinically, bruxers exhibited deteriorated PSQI, SAS, SDS and IRLSSG measures, polysomnographically impaired sleep maintenance, increased movement time, stage shift index, periodic leg movements (PLM) and arousals and psychometrically deteriorated subjective sleep and awakening quality, evening/morning well-being, drive, mood, drowsiness, attention variability, memory, and fine motor activity. As compared with placebo, clonazepam significantly decreased the SB index in all patients (mean: -42 +/- 15%). Sleep efficiency, maintenance, latency, awakenings and nocturnal wake time, the stage shift index, S1, PLM, the arousal index, subjective sleep and awakening quality, and fine motor activity improved.

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.

A novel GLRA1 mutation associated with an atypical hyperekplexia phenotype

Hyperekplexia (MIM #149400) is a rare neurological disorder characterized by an exaggerated startle response, infantile hypertonia and hyperreflexia without spasticity, a hesitant gait that usually improves by 3 years of age, and nocturnal myoclonus. Familial hyperekplexia is usually autosomal dominant resulting from mutations in the inhibitory glycine receptor subunit alpha 1 (GLRA1) gene on chromosome 5q. We identified a 3-generation family with progressively severe phenotypes of hyperekplexia. All affected family members were found to be heterozygous for a novel arginine271proline mutation in GLRA1. Long-term follow-up of the affected members of the third generation, now aged 6 and 7 years, reveals enhanced startle responses and persistent hypertonia of the extremities without clonus or a catch, tight heel cords and abnormal toe-walking gait, and plantar flexor reflexes. The 7-year-old child recently reponded well to a benzodiazepine. Future studies are warranted to examine whether this new missense mutation is solely responsible for this atypical phenotype.

Treatment of panic disorder: recent developments and current status

Panic disorder is a commonly encountered condition in general medical practice and in various medical settings. It is important for all medical practitioners to be able to recognize this disorder, provide patients with basic information and medical advice, and depending on the specific circumstances, to refer patients for appropriate treatment by primary care physicians, psychiatrists and/or clinical psychologists. This article reviews the developments in the treatment of panic disorder, focusing on the major treatment modalities of pharmacotherapy and cognitive-behavior therapy, as well as their combinations. In addition to providing information on current treatments for panic disorder and the main underlying treatment issues, the article identifies areas where improvements need to be made and areas where much research has been conducted in recent years. These include simplified modes of delivery of cognitive-behavior therapy, optimal ways of combining medications with cognitive-behavior therapy, and minimizing the risk of recurrence after the cessation of treatment.

Diagnosis and treatment of agoraphobia with panic disorder

Agoraphobia with panic disorder is a phobic-anxious syndrome where patients avoid situations or places in which they fear being embarrassed, or being unable to escape or get help if a panic attack occurs. During the last half-century, agoraphobia has been thought of as being closely linked to the recurring panic attack syndrome, so much so that in most cases it appears to be the typical development or complication of panic disorder. Despite the high prevalence of agoraphobia with panic disorder in patients in primary-care settings, the condition is frequently under-recognised and under-treated by medical providers. Antidepressants have been demonstrated to be effective in preventing panic attacks, and in improving anticipatory anxiety and avoidance behaviour. These drugs are also effective in the treatment of the frequently coexisting depressive symptomatology. Among antidepressant agents, SSRIs are generally well tolerated and effective for both anxious and depressive symptomatology, and these compounds should be considered the first choice for short-, medium- and long-term pharmacological treatment of agoraphobia with panic disorder. The few comparative studies conducted to date with various SSRIs reported no significant differences in terms of efficacy; however, the SSRIs that are less liable to produce withdrawal symptoms after abrupt discontinuation should be considered the treatments of first choice for long-term prophylaxis. Venlafaxine is not sufficiently studied in the long-term treatment of panic disorder, while TCAs may be considered as a second choice of treatment when patients do not seem to respond to or tolerate SSRIs. High-potency benzodiazepines have been shown to display a rapid onset of anti-anxiety effect, having beneficial effects during the first few days of treatment, and are therefore useful options for short-term treatment; however, these drugs are not first-choice medications in the medium and long term because of the frequent development of tolerance and dependence phenomena. Cognitive-behavioural therapy is the best studied non-pharmacological approach and can be applied to many patients, depending on its availability.

An open-label, multi-dose efficacy and safety study of intramuscular tetrodotoxin in patients with severe cancer-related pain

Cancer pain is a prevalent and serious public health issue, and more effective treatments are needed. This study evaluates the analgesic activity of tetrodotoxin, a highly selective sodium channel blocker, in cancer pain. A Phase IIa, open-label, multicenter, dose-escalation study of intramuscular tetrodotoxin was conducted in patients with severe, unrelieved cancer pain. The study design called for six ascending dose levels of intramuscular tetrodotoxin, administered over a four-day treatment period in hospitalized patients, with six patients to be enrolled within each successive dose level. Twenty-four patients underwent 31 courses of treatment at doses ranging from 15 to 90 microg daily, administered in divided doses, over four days. Most patients described transient perioral tingling or other mild sensory phenomena within about an hour of each treatment. Nausea and other toxicities were generally mild, but two patients experienced a serious adverse event, truncal and gait ataxia, that resolved over days. Seventeen of 31 treatments resulted in clinically meaningful reductions in pain intensity, and relief of pain persisted for up to two weeks or longer. Two patients had opioids held due to narcosis concurrent with relief of pain. Somatic, visceral, or neuropathic pain could all respond, but it was not possible to predict which patients were more likely to have an analgesic effect. Tetrodotoxin was overall safe. It effectively relieved severe, treatment-resistant cancer pain in the majority of patients and often for prolonged periods after treatment. It may have a novel mechanism of analgesic effect. Further study is warranted.

Clonazepam in the treatment of psychiatric disorders: an update

An updated overview over the past decade is provided with respect to the use of clonazepam in a variety of psychiatric disorders. The efficacy of clonazepam monotherapy for the short-term treatment of panic disorder (PD) was fully established in two large pivotal multicentre studies in the late 1990s in a total of >800 patients. Other studies support a role for clonazepam, in association with selective serotonin reuptake inhibitors (SSRIs), to accelerate treatment response in PD. Although some longitudinal data suggest an ability to maintain improvement without tolerance for up to 3 years, long-term controlled studies of clonazepam in PD are lacking. Studies have shown that clonazepam can also block CO2-induced panic and improve certain aspects of quality of life in PD. Clonazepam has shown some efficacy in social phobia; however, because this evidence is based on few studies, further studies are warranted before definitive conclusions can be drawn. Finally, evidence for the use of clonazepam in acute mania and as augmentation therapy with SSRIs to accelerate response in depression is examined. The long half-life and higher potency of clonazepam may allow easier discontinuation with fewer withdrawal symptoms compared to other benzodiazepines and studies using a slow clonazepam taper appear promising.

A three-year follow-up study of patients with the respiratory subtype of panic disorder after treatment with clonazepam

The demographic, clinical and therapeutic features of the respiratory subtype of panic disorder (PD) versus the non-respiratory subtype were studied in a prospective design. Sixty-seven PD outpatients (DSM-IV), who had previously been categorized into respiratory (n=35) and non-respiratory (n=32) subgroups, were openly treated with clonazepam for a 3-year period. The principal measure of efficacy was the number of panic attacks, obtained from the Sheehan Panic and Anticipatory Anxiety Scale. In the first 8 weeks of treatment (acute phase), the respiratory subtype group had a significantly faster response to clonazepam. During the follow-up (weeks 12-156), the two subgroups did not differ significantly in the number of panic attacks experienced from baseline to end point. Patients in the respiratory subtype were characterized by a later onset of disorder and a family history of PD. Patients in the non-respiratory subgroup had a significantly higher number of past depressive episodes than those in the respiratory subgroup. The respiratory subgroup had a faster response after 8 weeks of treatment and an equivalent response in the 3-year follow-up period. Clonazepam had a sustained therapeutic effect over the entire treatment period.

Obsessions with aggressive content emerging during the course of panic disorder: a different subtype of obsessive-compulsive disorder?

We report the clinical and therapeutic features of three patients with an obsessive-compulsive syndrome that emerged during the course of panic disorder. The DSM-IV criteria for panic disorder places central attention on the patient's phobic responses to the panic attacks and their perceived consequences. These phobic responses may develop into a syndrome that closely resembles obsessive-compulsive disorder (OCD) but typically responds to conventional anti-panic approaches. Our cases suggest that patients with OCD should be probed for an underlying panic disorder. This 'panic disorder-related subtype of OCD' may be associated with an excellent treatment response and increased rates of remission.

A meta-analysis of the efficacy of psycho- and pharmacotherapy in panic disorder with and without agoraphobia

The efficacy of (cognitive) behavioural ((C)BT) and pharmacological therapy was investigated using meta-analytic techniques. After a comprehensive review of the literature, the results of 124 studies were included. (C)BT was more effective than a no-treatment control and a placebo control. No difference of efficacy was found when using cognitive elements compared to not using them for anxiety; for associated depressive symptoms, additional cognitive elements seems superior. Pharmacotherapy was more effective than a placebo control; there was no superiority of any drug class. Sample size was related to effect size in pharmacotherapy and publication bias was found. (C)BT was at least as effective as pharmacotherapy and depending on type of analysis even significantly more effective. There were no significant differences between (C)BT alone and a combination approach but characteristics of studies have to be considered.

The Role of High-Potency Benzodiazepines in the Treatment of Panic Disorder

Medication plays a central role in the treatment of panic disorder, with the goal of eliminating panic attacks and restoring normal function (i.e., achieving full remission). Four drug classes have similar efficacy (tricyclic antidepressants, selective serotonin reuptake inhibitors [SSRIs], benzodiazepines, and monoamine oxidase inhibitors). Nonetheless, benzodiazepines remain the most prescribed medication for panic disorder in the United States. The high-potency benzodiaze-pines alprazolam (available as immediate- and extended-release tablets) and clonazepam (available as tablets and orally disintegrating wafers) are the only benzodiazepines approved by the U.S. Food and Drug Administration for the treatment of panic disorder. High-potency benzodiaze-pines, with their proven efficacy in panic disorder exerted through control of the central nervous system excitability by a selective and potent enhancement of inhibitory gamma-aminobutyric acid-mediated neurotransmission, are also a safe and well-tolerated option for potentiation of rapid treatment response when initiating treatment with SSRIs. Judicious use of high-potency benzodiazepines followed by a cautious taper and discontinuation may optimize the benefits and minimize any potential risk associated with this class of drugs.

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.

WCA recommendations for the long-term treatment of panic disorder

What are the symptoms of panic disorder and how is the disorder most effectively treated? One of the most commonly encountered anxiety disorders in the primary care setting, panic disorder is a chronic and debilitating illness. The core symptoms are recurrent panic attacks coupled with anticipatory anxiety and phobic avoidance, which together impair the patient's professional, social, and familial functioning. Patients with panic disorder have medically unexplained symptoms that lead to overutilization of healthcare services. Panic disorder is often comorbid with agoraphobia and major depression, and patients may be at increased risk of cardiovascular disease and, possibly, suicide. Research into the optimal treatment of this disorder has been undertaken in the past 2 decades, and numerous randomized, controlled trials have been published. Selective serotonin reuptake inhibitors have emerged as the most favorable treatment, as they have a beneficial side-effect profile, are relatively safe (even if taken in overdose), and do not produce physical dependency. High-potency benzodiazepines, reversible monoamine oxidase inhibitors, and tricyclic antidepressants have also shown antipanic efficacy. In addition, cognitive-behavioral therapy has demonstrated efficacy in the acute and long-term treatment of panic disorder. An integrated treatment approach that combines pharmacotherapy with cognitive-behavioral therapy may provide the best treatment. Long-term efficacy and ease of use are important considerations in treatment selection, as maintenance treatment is recommended for at least 12-24 months, and in some cases, indefinitely.

Comparative single-dose pharmacokinetics of clonazepam following intravenous, intramuscular and oral administration to healthy volunteers

The objective was to assess the single-dose pharmacokinetics of clonazepam following i.m., p.o. and i.v. administration. In an open-label, three-way crossover study, 12 healthy volunteers were randomized to receive a single dose of 2 mg clonazepam either by the i.m., p.o. or i.v. route. Serial blood samples were collected up to 120 h after drug administration. Plasma concentrations of clonazepam were determined by electron-capture gas-liquid chromatography. The absorption rates of clonazepam after i.m. and p.o. administration of clonazepam were significantly different from each other, as reflected by the respective mean values of maximum plasma concentration (C(max) 11.0 vs. 14.9 ng.ml(-1)) and time to reach maximum concentration (t(max) 3.1 vs. 1.7 h). Secondary plasma peaks of clonazepam were observed in 9 volunteers after i.m. injection (C(max) 9.9 ng.ml(-1); t(max) 10.4 h). A comparison of the area under the plasma concentration-time curves (AUC) shows that the i.m. route is equivalent to the oral route (AUC(0- infinity ) 620 vs. 561 ng.h.ml(-1)). Clonazepam was almost completely absorbed after i.m. and p.o. administration, as shown by the mean absolute bioavailability of 93 and 90%, respectively. No significant differences existed between the elimination half-lives (i.v. 38.0 h; i.m. 43.6 h; p.o. 39.0 h). The average clearance and volume of distribution (V(Z)) were 55 ml.min(-1) and 180 liters, respectively. In conclusion, the observed differences in C(max) and t(max) after i.m. and p.o. administration were consistent with a slower absorption rate of clonazepam after i.m. injection. The systemic exposure to clonazepam was not affected by the route of extravascular administration. Statistical evaluation of these kinetic data showed differences in the absorption rate, so that clonazepam given by the i.m. route is not bioequivalent to the oral route. On the basis of the results of this study, we would recommend the same i.m. and p.o. dose in epileptic patients, but therapeutic response would be expected to be less predictable and to occur later in the case of i.m. administration.

Therapeutic response to benzodiazepine in panic disorder subtypes

CONTEXT

This study makes a comparison between two subtypes of panic disorder regarding the clinical efficacy of clonazepam, a benzodiazepine.

OBJECTIVES

To evaluate the clinical efficacy of clonazepam in a fixed dosage (2 mg/day), compared to placebo, in the treatment of panic disorder patients and to verify whether there are any differences in the responses to clonazepam between panic disorder patients with the respiratory and non-respiratory subtypes.

TYPE OF STUDY

Randomized study with clonazepam and placebo.

SETTING

Outpatient Anxiety and Depression Unit of the Institute of Psychiatry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.

PARTICIPANTS

34 patients with a diagnosis of panic disorder with agoraphobia, between 18 and 55 years old.

PROCEDURES

Administration of clonazepam or placebo for 6 weeks, in panic disorder patients, after they were classified within two subtypes of panic disorder: respiratory and non-respiratory.

MAIN MEASUREMENTS

Changes in the number of panic attacks in comparison with the period before the beginning of the study; Hamilton Anxiety Scale; Global Clinical Impression Scale; and Patient's Global Impression scale.

RESULTS

In the group that received clonazepam, by the end of the 6th week there was a statistically significant clinical improvement, shown by the remission of panic attacks (p < 0.001) and decrease in anxiety (p = 0.024). In the group that received clonazepam there was no significant difference between the respiratory and non-respiratory subtypes of panic disorder, regarding the therapeutic response to clonazepam.

CONCLUSION

Clonazepam was equally effective in the treatment of the respiratory and non-respiratory subtypes of panic disorder, suggesting there is no difference in the therapeutic response between the two subtypes.

Pharmacotherapy of anxious disorders

The present paper is a review of the treatment of anxious disorders by the current pharmaceutical medications; a short epidemiological survey is given for anxious disorders including: general anxiety disorder, panic disorder, obsessive compulsive disorder, social anxiety and post-traumatic stress disorder. For all these disorders there are proposals of treatment built on literature data mainly on meta-analysis as well on personal experience.

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.

Panic Disorder and Chest Pain: Mechanisms, Morbidity, and Management

Approximately one quarter of patients who present to physicians for treatment of chest pain have panic disorder. Panic disorder frequently goes unrecognized and untreated among patients with chest pain, leading to frequent return visits and substantial morbidity. Panic attacks may lead to chest pain through a variety of mechanisms, both cardiac and noncardiac in nature, and multiple processes may cause chest pain in the same patient. Panic disorder is associated with elevated rates of cardiovascular diseases, including hypertension, cardiomyopathy, and, possibly, sudden cardiac death. Furthermore, patients with panic disorder and chest pain have high rates of functional disability and medical service utilization. Fortunately, panic disorder is treatable; selective serotonin reuptake inhibitors, benzodiazepines, and cognitive-behavioral psychotherapy all effectively reduce symptoms. Preliminary studies have also found that treatment of patients who have panic disorder and chest pain with benzodiazepines results in reduction of chest pain as well as relief of anxiety.

Panic disorder: the place of benzodiazepines and selective serotonin reuptake inhibitors

This article reviews the efficacy of the benzodiazepines and the selective serotonin reuptake inhibitor class of antidepressant in the treatment of panic disorder. The benzodiazepine alprazolam has been used successfully in the treatment of panic disorder, but its long-term use presents problems with dependence. Since panic may be mediated by a dysfunction of serotonin neuronal pathways, there is a rationale for treatment with antidepressants that modulate serotonergic systems. In clinical trials, members of the SSRI class of antidepressant reduced panic attack frequency to zero in 36-86% of patients and were well tolerated over long-term administration, all important factors in ensuring patient compliance. In addition, antidepressants are preferable to benzodiazepines in the treatment of panic and comorbid depression, of which there is a high prevalence among panic disorder patients. This review emphasises the need for long-term treatment of this chronic and disabling condition with a therapy that is well tolerated and provides complete and sustained recovery from panic attacks, and resolution of anticipatory anxiety.

Obstetrical and neonatal outcome following clonazepam use during pregnancy: a case series

BACKGROUND

Given the high prevalence of panic disorder in women, treatment decisions are frequently made regarding the use of anti-panic medications during the childbearing years and during pregnancy. The objective of this case series was to evaluate obstetric and neonatal outcome associated with treatment with clonazepam during pregnancy.

METHODS

Subjects were 38 women with histories of panic disorder who used clonazepam during pregnancy. Information regarding the amount and duration of clonazepam use during pregnancy was obtained. Obstetrical records describing pregnancy, labor and delivery and infant Apgar scores were obtained for all subjects. Neonatal nursery records were obtained for 27 subjects.

RESULTS

Maternal outcome assessed by obstetrical records and acute neonatal outcome assessed by Apgar scores were positive. Based on neonatal records, there were no cases of orofacial anomalies, neonatal apnea, benzodiazepine withdrawal syndromes, or temperature or other autonomic dysregulation. In 2 infants born to the same mother, use of clonazepam and imipramine at the time of delivery was associated with transient neonatal distress.

CONCLUSION

Clonazepam use during pregnancy did not appear to be directly related to any obstetric complications during pregnancy, labor, or delivery. There was no evidence of neonatal toxicity or withdrawal syndromes in babies born to mothers who took clonazepam during pregnancy. Absence of serious maternal or neonatal compromise following clonazepam use during pregnancy in these mothers and infants is somewhat reassuring. One case of hypotonia and 1 case of respiratory distress in babies who were exposed to clonazepam in combination with imipramine at the time of delivery may suggest that coadministration of benzodiazepines with other psychotropic medications may require close neonatal observation.

Double-blind clonazepam vs placebo in panic disorder treatment

OBJECTIVE

To assess the effectiveness of clonazepam, in a fixed dose (2 mg/day), compared with placebo in the treatment of panic disorder patients.

METHOD

24 panic disorder patients with agoraphobia were randomly selected. The diagnosis was obtained using the structured clinical interview for DSM-IV. All twenty-four subjects were randomly assigned to either treatment with clonazepam (2 mg/day) or placebo, during 6 weeks. Efficacy assessments included: change from baseline in the number of panic attacks; CGI scores for panic disorder; Hamilton rating scale for anxiety; and panic associated symptoms scale.

RESULTS

At the therapeutic endpoint, only one of 9 placebo patients (11.1%) were free of panic attacks, compared with 8 of 13 (61.5%) clonazepam patients (Fisher exact test; p=0,031).

CONCLUSION

the results provide evidence for the efficacy of clonazepam in panic disorder patients.