Two anti-anxiety drugs: a psychoneuroendocrine study

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.

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.

Alcohol and benzodiazepines generate anxiety, panic and phobias

In almost half the patients seeking advice for anxiety, panic and phobias the cause was alcohol or benzodiazepines. In the remainder it was psychological, usually a state of conflict or a traumatic event. When symptoms are persistent following a distressing event it is often the case that alcohol or benzodiazepines are keeping them going. There is a large variation in individual vulnerability and the mechanism responsible for these symptoms is rebound arousal.

Absence of withdrawal effects of ritanserin following chronic dosing in healthy volunteers

The possible development of withdrawal symptoms following abrupt discontinuation of ritanserin after chronic administration of 10 mg daily for 8 weeks was investigated in a placebo controlled trial in 40 healthy subjects. The study consisted of two phases. In the first phase, under single blind conditions, all subjects received placebo for 2 weeks followed by a single daily dose of ritanserin (10 mg) for 8 weeks. In the second phase, under double blind conditions, subjects were randomised to receive either placebo or to continue on ritanserin (10 mg) for a further 4 weeks. Psychological assessments were performed at the start of and at intervals throughout the study. Levels of anxiety, concentration, quality of sleep and morning vigilance were measured throughout by daily visual analogue scales. No significant changes were detected in any of the measures in the group of subjects who received ritanserin compared to the group who received placebo during the second phase of the study. Ritanserin discontinuation following chronic dosing in healthy volunteers does not appear to be associated with withdrawal symptoms.

Hypnotics and sleep physiology: a consensus report. European Sleep Research Society, Committee on Hypnotics and Sleep Physiology

The effects of hypnotics on descriptive and functional aspects of electrophysiological sleep parameters are assessed in this report. Because of the arbitrary definition of some of the criteria underlying the conventional sleep stage scoring procedure, computer-aided methods of EEG analysis have become increasingly important for recording and interpreting pharmacological effects on sleep. Of particular interest are the changes of EEG slow-wave activity, since this parameter varies as a function of prior sleep and waking. Several types of interaction between hypnotics and sleep regulation are discussed, some recent pharmacological developments are highlighted, and some common problems in clinical trials are specified.

Influence of therapeutic phenobarbital and phenytoin medication on the polygraphic sleep of patients with epilepsy

Sleep is a modulator of seizure activity, and many antiepileptic drugs are modulators of sleep. Can influences on sleep organization be involved in antiepileptic drug action, and can these partly account for differences in drug response of various epileptic syndromes? Much more exact data must be collected before these questions can be adequately discussed. The polygraphic sleep of 40 unmedicated epileptic patients was recorded and compared with polygraphy after adjustment to therapeutic steady states of phenobarbital (PB) and phenytoin (DPH) (as sequential sole agents in a crossover design with random sequence). With PB, patients fell asleep more rapidly and had fewer movements, movement arousals, and arousal awakenings, all of which could be beneficial, especially for patients with generalized epilepsy. Light sleep was increased, and REM sleep decreased. The usual sleep pattern was altered, with maximal deep sleep early and maximal REM sleep late in the night. PB seemed to have maximal effect in the first REM cycle. With DPH, sleep onset also came sooner, but light sleep was decreased and deep sleep increased, with no alteration of REM sleep. In contrast to PB, the changes in sleep organization were toward leveling the distribution of deep NREM sleep. The maximal alterations were observed in the third REM cycle. With both drugs, there were some differences in the response of generalized as opposed to focal epilepsies, and of awakening as opposed to sleep epilepsies. Thus, the early REM cycles seemed to be more modifiable by drugs in patients with generalized or awakening epilepsies than in patients with focal or sleep epilepsies.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of lormetazepam and of flurazepam on sleep

Nine poor sleepers of mean age 61 years took part in a double-blind, balanced order study in which, during three periods of 3 weeks, each took lormetazepam 1 mg, lormetazepam 2.5 mg, and flurazepam 30 mg. Using electrophysiological measures, sleep was found to increase by 0.75 h with each treatment condition, mainly through more of stage 2 sleep. The treatments reduced the delay to sleep and led to fewer and shorter awakenings, with little difference among the three treatments. Slow-wave sleep was reduced by flurazepam and by lormetazepam 2.5 mg. After flurazepam intake ceased, there was evidence of persisting drug effects for as long as 7 nights. In contrast, when lormetazepam 2.5 mg ceased, there was significant rebound reduction of sleep duration below baseline for up to 3 withdrawal nights, and there was a similar though non-significant trend after lormetazepam 1 mg had ceased. Wakefulness in the final 2 h of nocturnal recording during the third week of drug intake was significantly reduced below baseline by flurazepam, but was little affected by lormetazepam. The differences among the treatment conditions could be attributed to the long-persistence of flurazepam vs the more rapid elimination of lormetazepam.

Effects of loprazolam and of triazolam on sleep and overnight urinary cortisol

Nine poor sleepers of mean age 61 years were studied while they took loprazolam 0.5 mg, loprazolam 1 mg and triazolam 0.5 mg for 3-week periods. Loprazolam 1 mg and triazolam 0.5 mg increased sleep duration, but there was some tolerance to both, particularly triazolam, by the 3rd week. Withdrawal of either drug led to sleep significantly shorter than baseline. This rebound effect was significant greater than withdrawing triazolam. After withdrawing loprazolam 1 mg, the rebound was maximal on the 3rd night and after withdrawing triazolam it was maximal and severe on the 1st night. In the third week of use neither drug was associated with late-night wakefulness. Total overnight urinary cortisol was lower during drug intake and there were significant withdrawal rebounds to above baseline levels, immediately so after triazolam.

Are poor sleepers changed into good sleepers by hypnotic drugs?

Sleep can be measured by subjective ratings, electrophysiological recordings and by the physiological and biochemical changes occurring with sleep. Using these methods, we can select those who rate their sleep as unsatisfactory and those who feel fully satisfied by their sleep. Electrophysiological recordings of sleep show that there are relatively small differences between these good and poor sleepers: poor sleepers sleep less than good sleepers, but not as little as they think. However, the complaints of poor sleepers that they feel unrestored by their sleep should not be dismissed, for investigations employing the tools of physiology and biochemistry have revealed differences between good and poor sleepers that suggest that the sleep of poor sleepers may indeed be less restorative. The actions of hypnotic drugs on sleep can be similarly investigated. Preliminary findings suggest that hypnotic drugs may reverse some of the detrimental metabolic concomitants of poor sleep.

Effects of selective sleep deprivation on sleep-linked prolactin and growth hormone secretion

1. The secretion of prolactin and growth-hormone (hGH) was investigated during sleep in 10 healthy volunteers (8 males and 2 females): The comparison of one baseline night, one night after daytime physical exercise, and one night with selective deprivation of sleep stages 3 and 4 and paradoxical sleep showed clear differences of prolactin and hGH secretion during sleep. 2. Prolactin secretion is entrained into the sleep cycle of Non-REM and REM periods. A maximum of plasma hormone elevations occurs during the first quarter of sleep cycles, i.e., during Non-REM periods and less frequent rises at the end of the cycles, mainly during REM periods. 3. In contrast to growth hormone, concentrations of prolactin remain high also during later cycles occurring toward morning. This shows that high prolactin, but not high concentrations of hGH, regularly occur during sleep cycles with small amounts of slow-wave sleep. 4. Maximal prolactin concentrations during sleep are affected neither by preceding daytime physical exercise nor by selective deprivation of slow sleep stages 3 and 4. This is further evidence that slow-wave sleep stages are not necessary for the development of high plasma prolactin concentrations. However, peak values of growth hormone in the first and second cycle are significantly diminished after selective deprivation of sleep stages 3 and 4. 5. In abnormally long sleep cycles with artificial delay of the first REM period, the cyclical rhythmicity of prolactin release seems disturbed. This is further evidence for the sleep-dependent rhythmicity in the secretion of this hormone.

Temperature and endocrine activity during sleep in man. Activation of cortisol and thyroid-stimulating hormone, inhibition of human growth hormone secretion by raised or decreased ambient and body temperatures

1. Polygraphic night sleep recordings in eight healthy male volunteers with simultaneous measurement of rectal temperature, plasma growth hormone (HGH), cortisol, and TSH concentrations were performed during normal, raised, and lowered ambient and body temperature. 2. There was a statistically significant increase in plasma cortisol and TSH levels during cold nights with a smaller rise during high temperatures. 3. Growth hormone levels, measured as the mean highest plasma concentration in the first two NREM-REM sleep cycles, were slightly lower during hot and cold nights than corresponding baseline values. It is suggested that there may be an inverse relation between ACTH and HGH secretion by the anterior pituitary gland. 4. During the nights of high ambient temperature, decreased total duration of sleep and particularly low values of paradoxical sleep were observed. Night sleep in low ambient temperature with a significant decrease of body temperature is not different from baseline conditions. 5. The results suggest that a pronounced increase in stress hormone secretion may occur without changes in polygraphic EEG criteria.

Mesoridazine and human sleep

1 Mesoridazine, a phenothiazine of short half-life, and potentially useful as an hypnotic, has here been investigated using volunteers of late middle age. 2 The electrophsiological recording of all-night sleep was studied in seven subjects for a 7-week period during which ther received mesoridazine (10 mg nightly) for 3 weeks. The drug reduced the frequency of transitions into wakefulness and stage 1 (drowsiness) and reduced the time spent in stage 1; there was a withdrawal rebound. Mesoridazine increased REM sleep above baseline levels and a rebound fall below baseline occurred on withdrawal. The drug did not alter the amount of stage 3 + 4 slow wave sleep. 3 Subjective self-ratings were assessed in a 6-week study of sixteen subjects. Sleep quality improved on mesoridazine (10 mg nightly) but there was diminution of zest and freshness 20 min after rising. Daytime concentration and anxiety were rated as not affected either by administration or withdrawal.

Sleeping pills and dream content

Almost all sleep-promoting drugs distort the natural pattern of sleep by suppressing rapid eye movement (REM) sleep, and cause a rebound to above-normal values on withdrawal which typically lasts about six weeks (Oswald, 1968, 1969). Furthermore, barbiturates reduce the number of eye movements per unit time in REM sleep (Oswald et al., 1963; Baekeland, 1967; Lester et al., 1968; Feinberg et al., 1969), with a rebound in eye movement (EM) profusion on withdrawal (Oswald, 1970). Non-barbiturate hypnotics do likewise, also with a rebound in EM profusion on withdrawal (Allen et al., 1968; Lewis, 1968).