Effects of clorazepate, diazepam, lorazepam, and placebo on human memory

Healthy adults (N = 10) were given oral doses of lorazepam (1 and 2 mg), diazepam (5 and 10 mg), clorazepate (7.5 and 15 mg), or placebo and tested 30, 60, 90, and 120 minutes later on a word-recall memory task. All subjects received each drug dose once and placebo twice in randomized order at weekly intervals. Testing was double-blind. Lorazepam was found to have a significantly greater effect on memory than placebo. Diazepam and clorazepate did not differ significantly from placebo in their effect on word recall. High doses of lorazepam produced more pronounced memory effects than did low doses; neither diazepam nor clorazepate was found to exert a dose-related effect on memory.     

Lack of amnestic effects of clorazepate on geriatric recall

Significant amnestic effects in young adults have been found with the short-acting sedative-hypnotic triazolam and the intermediate-acting lorazepam, but not with the longer-acting clorazepate. The effects of placebo and clorazepate 3.75 and 7.5 mg were compared in 43 nonanxious geriatric subjects. Results were consistent with earlier studies, and no significant impairment of immediate or delayed recall was found.     

Efficacy and withdrawal of clobazam, lorazepam and buspirone in the treatment of anxiety disorders

This multicentre study was conducted to evaluate the efficacy and consequences of progressive or abrupt withdrawal of clobazam in the treatment of Generalized Anxiety Disorder in a double blind study in comparison to lorazepam and buspirone. 128 outpatients suffering from Generalized Anxiety Disorder according to DMS III criteria were included in the study and treated for three weeks. They were randomly divided into 4 groups: group 1: 32 patients receiving clobazam, abruptly withdrawn and replaced by a placebo; group 2: 29 patients receiving clobazam with progressive withdrawal over 3 weeks, clobazam being replaced by a placebo; group 3: 33 patients receiving lorazepam with progressive withdrawal over 3 weeks, lorazepam being replaced by a placebo; group 4: 34 patients receiving buspirone, abruptly withdrawn and replaced by a placebo. The dosages were increased progressively during the first week of treatment. At the end of this time, the patients received either 30 mg clobazam or 30 mg buspirone or 3 mg lorazepam daily. After the first week, the Hamilton Anxiety Rating Scale (HARS) showed a significant improvement in clobazam and lorazepam groups but not in buspirone group. All the drugs were equally effective after three weeks of treatment. The anti-anxiety activity persisted after withdrawal of the studied drug in the 4 groups, without any signs of rebound anxiety or withdrawal syndrome. No clinically relevant differences were found between the 4 groups regarding safety. The side-effects reported were mainly drowsiness in clobazam and lorazepam groups, nausea and headache in buspirone group. In conclusion, clobazam like lorazepam improved anxiety more quickly than buspirone; after 3 weeks of therapy, efficacy was comparable with the 3 drugs and persisted after treatment discontinuation.     

Benzodiazepines in epilepsy: pharmacology and pharmacokinetics

Benzodiazepines (BZDs) remain important agents in the management of epilepsy. They are drugs of first choice for status epilepticus and seizures associated with post-anoxic insult and are also frequently used in the treatment of febrile, acute repetitive and alcohol withdrawal seizures. Clinical advantages of these drugs include rapid onset of action, high efficacy rates and minimal toxicity. Benzodiazepines are used in a variety of clinical situations because they have a broad spectrum of clinical activity and can be administered via several routes. Potential shortcomings of BZDs include tolerance, withdrawal symptoms, adverse events, such as cognitive impairment and sedation, and drug interactions. Benzodiazepines differ in their pharmacologic effects and pharmacokinetic profiles, which dictate how the drugs are used. Among the approximately 35 BZDs available, a select few are used for the management of seizures and epilepsy: clobazam, clonazepam, clorazepate, diazepam, lorazepam and midazolam. Among these BZDs, clorazepate has a unique profile that includes a long half-life of its active metabolite and slow onset of tolerance. Additionally, the pharmacokinetic characteristics of clorazepate (particularly the sustained-release formulation) could theoretically help minimize adverse events. However, larger, controlled studies of clorazepate are needed to further examine its role in the treatment of patients with epilepsy.     

Depressive symptoms and intellectual functioning in anxiety patients treated with clorazepate

The combined data from two 1970s anxiety studies that used clorazepate and placebo as controls were reanalyzed statistically with a focus on intellectual functioning and depressive symptoms. For the 176 patients given either clorazepate or placebo, significant improvement was observed on the mean scores of the intellectual item and the depressive item of the Hamilton Rating Scale for Anxiety; the clorazepate group was significantly more improved than the placebo group. Similar results were observed in patients' self-ratings. The authors conclude that clorazepate is effective in treating depressive symptoms and improving intellectual functioning in patients with generalized anxiety disorder.     

Differential amnestic properties of short- and long-acting benzodiazepines

It has been demonstrated previously that orally administered lorazepam can cause anterograde amnesia in young adults. In this study, the effects of 7.5 and 15 mg clorazepate and 1 and 2 mg lorazepam on recall were compared in 74 healthy adults. Word list presentation tests were administered to subjects at selected intervals to measure immediate and delayed recall. Statistically significant memory impairment was found with 2 mg lorazepam during both immediate and delayed recall testing. Clorazepate produced no statistically significant amnestic effects. The data suggest that benzodiazepines differ in their potential for causing memory impairment.     

Bromazepam and lorazepam in generalized anxiety: a placebo-controlled study with measurement of drug plasma concentrations

Sixty outpatients with a diagnosis of generalized anxiety were randomly assigned to 4 weeks of treatment with bromazepam, lorazepam or placebo, following a 1-week placebo washout period. There was no significant difference in the anxiolytic effects of bromazepam and lorazepam, both of which were superior to placebo. However, lorazepam-treated patients tended to have a more depressed mood than those treated with bromazepam. Drug-treated patients had consistently less cognitive impairment than those treated with placebo, the difference being statistically significant (P less than .05) in the case of bromazepam. The most frequent side-effects reported with each drug were drowsiness, which tended to subside with time, and depression, which tended to emerge toward the end of the 4-week period. There was a positive correlation (r = 0.64) between age and bromazepam plasma concentration per unit dose, adjusted for weight, and a negative correlation (r = -0.50) between weight and lorazepam plasma concentration per unit dose, adjusted for age.     

Long-term treatment of anxiety and risk of withdrawal. Prospective comparison of clorazepate and buspirone

Risk of withdrawal was investigated in a prospective, double-blind comparison of clorazepate dipotassium, a benzodiazepine with a long half-life, and the nonbenzodiazepine buspirone hydrochloride in the long-term treatment of anxious outpatients. Patients were treated with therapeutic doses of clorazepate dipotassium (15 to 60 mg/d) or buspirone hydrochloride (10 to 40 mg/d) for six continuous months before their tranquilizer therapy was blindly and abruptly stopped. There was a significant increase in symptom severity consistent with a withdrawal reaction for the clorazepate group but not the buspirone group. For the clorazepate group, there was a suggestion that previous discontinuous exposure to benzodiazepines might sensitize patients to subsequent withdrawal effects. For the buspirone group, a higher dropout rate raised questions about patient satisfaction with therapy in this rather chronically anxious population.     

The influence of ritanserin, a serotonin antagonist, in anxiety disorders: a double-blind placebo-controlled study versus lorazepam

A double-blind study was performed in 83 patients with generalized anxiety disorder comparing daily doses of 5 and 10 mg ritanserin (a selective antagonist of serotonine S2 receptors) versus placebo and 4 mg lorazepam as reference drug. Patients treated with 10 mg ritanserin or 4 mg lorazepam improved significantly better (p less than 0.05) after two weeks than those treated with placebo. On the other hand a daily dose of 5 mg ritanserin appeared to be not superior to placebo. Patients treated with 4 mg lorazepam complained significantly more about sedation and dizziness than patients treated with 10 mg ritanserin (p less than 0.05).     

Differences in the effect of two benzodiazepines in the treatment of anxious outpatients

60 anxious patients received either 3 mg lorazepam or 30 mg clobazam daily for 4 weeks preceded and followed by a 1-week placebo treatment. Both drugs were equally effective in changing the ratings of anxiety obtained on the Hamilton anxiety rating scale, the Leeds self assessment scale and visual analogue scales. Statistically significant differences between the two drugs were observed after the final week on placebo. In the patients treated with lorazepam the psychic anxiety scores worsened and began to return to their pre-drug levels. This reoccurrence of the symptoms of anxiety was not noticed in the patients treated with clobazam.     

Clinical Evaluation of the Daily Assessment of Symptoms‐Anxiety (DAS‐A): A New Instrument to Assess the Onset of Symptomatic Improvement in Generalized Anxiety Disorder

Introduction: Rapid onset of symptomatic improvement is a desirable characteristic of new generalized anxiety disorder (GAD) treatments. A validated rating scale is needed to assess GAD symptoms during the first days of treatment. Aims: To provide clinical data to support the validation of the Daily Assessment of Symptoms‐Anxiety (DAS‐A), a new instrument to assess onset of symptomatic improvement in GAD. Methods: We assessed the ability of the DAS‐A to detect onset of symptomatic improvement during the first week of therapy in 169 GAD patients randomized to paroxetine 20 mg/day, lorazepam 4.5 mg/day, or placebo for 4 weeks. Results: On the primary outcome measure, average change from baseline over the first 6 days of DAS‐A assessments, lorazepam (?14.5 ± 1.8 [LS mean, SE]; P= 0.006 vs. placebo) showed a significant improvement versus placebo (?7.85 ± 1.7), whereas paroxetine (?8.3 ± 1.7; P= 0.83 vs. placebo) did not. Lorazepam produced a significant treatment effect on the DAS‐A at 24 h (P= 0.0004), whereas paroxetine did not (P= 0.5666). Both active drugs produced statistically significant improvement versus placebo on the DAS‐A total change score (last‐observation carried forward method; LOCF, endpoint). On the DAS‐A total change score (observed cases analysis), lorazepam produced statistically significant improvement versus placebo at weeks 1, 2, and 4 (P < 0.05; no week 3 visit), whereas paroxetine, separated from placebo at weeks 2 and 4 (P < 0.05). Both active drugs produced results on the Hamilton Anxiety Rating Scale (HAM‐A) at weeks 1 through 4 that were similar to those found on the DAS‐A. Conclusions: These data indicate that the DAS‐A can detect symptomatic improvement in GAD patients treated with lorazepam during the first week of treatment, and, in a secondary analysis, as early as 24 h.     

Lorazepam: a controlled trial in patients with intractable partial complex seizures

Lorazepam was studied in a double-blind, placebo-controlled, crossover trial in eight patients with frequent partial complex seizures refractory to therapy with a combination of standard anticonvulsant drugs. Concomitant antiepileptic drugs were maintained at therapeutic serum levels throughout the study, and concentrations of lorazepam were monitored. Following an 8-week baseline observation, patients were randomly assigned to placebo or lorazepam (1 mg BID). The dose was increased biweekly until seizures stopped or unacceptable side effects occurred. Eight weeks later, patients were crossed over, and the same escalating dose paradigm was followed. When seizure frequency during the last 2 weeks of each treatment was compared, seven of eight patients had fewer seizures on lorazepam, and the eighth had decreased seizure duration (a significant difference: p less than 0.01, two-tailed sign test). Blood level data suggest a narrow therapeutic window, with seizure improvement occurring at concentrations of 20-30 ng/ml and side effects at greater than 33 ng/ml. Lorazepam appears to be a useful adjunct in refractory partial complex seizure therapy. It should not be stopped abruptly, as an increase in seizure frequency may result.     

Lorazepam vs. alprazolam in the treatment of panic disorder

Sixty-seven patients with panic disorder were treated with single-blind placebo for one week before being randomized to 6 weeks of double-blind treatment with either lorazepam or alprazolam. Both drugs showed significant and comparable antipanic efficacy throughout the course of the study. With the exception of sedative effects, both drugs were well-tolerated at a mean daily dose of 7 mg for lorazepam and 3 mg for alprazolam. Lorazepam appeared to be as effective as alprazolam in the acute treatment of panic disorder.     

Pregabalin in generalized anxiety disorder: a placebo-controlled trial

OBJECTIVE: Current drug therapies for generalized anxiety disorder have limitations. In a controlled trial, the novel agent pregabalin was studied for the treatment of patients with generalized anxiety disorder. METHOD: In this double-blind study, patients with DSM-IV generalized anxiety disorder were randomly assigned to receive pregabalin (150 mg/day or 600 mg/day), lorazepam (6 mg/day), or placebo. A 1-week placebo lead-in was followed by 4 weeks of treatment and then a 1-week dose taper. The primary efficacy measure was the Hamilton Anxiety Rating Scale score at endpoint. RESULTS: A total of 276 patients were randomly assigned to a treatment group and received at least one dose of their assigned medication. Fewer patients given lorazepam (59%, N=40 of 68) completed the trial than did those given placebo (73%, N=50 of 69), 600 mg/day of pregabalin (71%, N=50 of 70), or 150 mg/day or pregabalin (90%, N=62 of 69). The mean baseline-to-endpoint decreases in total Hamilton anxiety scale score in the patients given 150 mg/day of pregabalin (-9.2), 600 mg/day of pregabalin (-10.3), and lorazepam (-12.0) were significantly greater than the decrease in those given placebo (-6.8). As early as the week 1 observation, pregabalin significantly reduced the total Hamilton anxiety scale score compared with placebo. The most frequent adverse events reported for pregabalin and lorazepam were somnolence and dizziness. There were no serious adverse events reported by patients given pregabalin, and no withdrawal syndrome was associated with pregabalin treatment. CONCLUSIONS: These results indicate that pregabalin is an effective, rapidly acting, and safe treatment for generalized anxiety disorder. In short-term treatment, pregabalin does not appear to have the withdrawal symptoms associated with the benzodiazepines.     

Effect of clorazepate in spasticity and rigidity: a quantitative study of reflexes and plasma concentrations

The effect on increased myotatic reflexes of desmethyldiazepam, formed from its precursor clorazepate, was assessed in a double-blind cross-over study of 27 days duration. Eight patients with spasticity or rigidity were given placebo or active substance; first in loading doses for 2 days, then 5 mg every 12 h for a total of 10 days. A wash-out period of 7 days was interposed between the 2 10-day periods. Desmethyldiazepam had a normalizing effect on the increased phasic ankle reflexes seen in spasticity, but not on the increased tonic reflex seen in rigidity. The mean concentration of desmethyldiazepam in the steady state was 1227 nmol/l (range 600-1990 nmol/l). The plasma concentration of desmethyldiazepam tended to correlate with the percent decrease in phasic reflex activity (P = 0.08, 2-tailed). A slight drowsiness in 2 patients was the only side-effect seen. In conclusion, desmethyldiazepam given as clorazepate seems to be a suitable medicament in the treatment of spasticity.     

Clorazepate in dogs: tolerance to the anticonvulsant effect and signs of physical dependence

Dogs were treated with clorazepate, which is known to be completely metabolized to desmethyldiazepam. 2 mg/kg t.i.d. were given orally for 5-6 weeks, a dose regimen providing plasma concentrations of desmethyldiazepam in the range known to be therapeutic in man. The rate of development of tolerance to the anticonvulsant effect was followed by weekly determinations of the convulsive threshold for pentetrazole before, during and after cessation of treatment. The development of tolerance was not as clear and pronounced as that found after treatment with diazepam and clonazepam in earlier studies with dogs. The seizure threshold was elevated by a factor of 1.2-3.5 during the first 2 weeks of treatment; during the following weeks, tolerance developed in only 2 out of 6 dogs (decline of the pentetrazole threshold in spite of rising or unchanged plasma concentrations). 36 h after withdrawal of clorazepate, the convulsive threshold had fallen below the control values in all dogs, but 1 week later it had returned to the control level. One day after cessation of treatment, 2 out of 6 dogs showed withdrawal seizures, which, in 1 case, were lethal. This shows that severe withdrawal symptoms, even lethal seizures, may appear after abrupt discontinuation of chronic clorazepate treatment, in spite of the relatively low tolerance liability of clorazepate.     

Antiepileptic effect and serum levels of clorazepate on children with refractory seizures

Clorazepate dipotassium is rapidly decarboxylated to yield desmethyl diazepam. The antiepileptic effect of clorazepate was studied in 29 epileptic children with refractory seizures. Their ages were ranged from one year 9 months to 20 years (mean 11 years 6 months). Serum clorazepate levels were also determined in 16 patients. The mean initial dose was 0.91 mg/kg/day, and the dose was increased up to 3 mg/kg/day. Within several days after initiation of clorazepate therapy, a decrease in seizure frequency was seen in patients in whom clorazepate was effective. Excellent results (decrease in seizure frequency by more than 80%) were obtained in 7 patients (24.1%), a moderate improvement with a 50 to 80% decrease was seen in 7 patients (24.1%), and a partial improvement with less than 50% decrease was seen in 7 patients (24.1%). No benefit was seen in 8 patients (27.7%). Serum clorazepate levels in patients with excellent results were 31 to 77 ng/ml (mean 55 ng/ml), those in patients with a moderate improvement were 130 to 225 ng/ml (mean 163 ng/ml), and those in patients with a partial improvement were 142 to 518 ng/ml (mean 273 ng/ml). Serum clorazepate levels in patients with no benefit were 34 to 97 ng/ml (mean 56 ng/ml). There was no direct relationship between serum clorazepate levels and clinical response. The results of this study indicate the efficacy of clorazepate for epileptic children with refractory seizures.     

Imipramine and buspirone in treatment of patients with generalized anxiety disorder who are discontinuing long-term benzodiazepine therapy

OBJECTIVE: Patients with generalized anxiety disorder (N=107) who had been long-term benzodiazepine users (average duration of use=8.5 years) were enrolled in a benzodiazepine discontinuation program that assessed the effectiveness of concomitant imipramine (180 mg/day) and buspirone (38 mg/day) compared to placebo in facilitating benzodiazepine discontinuation. METHOD: After a benzodiazepine stabilization period taking either diazepam, lorazepam, or alprazolam, patients were treated for 4 weeks with imipramine, buspirone, or placebo under double-blind conditions while benzodiazepine intake was kept stable (treatment phase). Patients then entered a 4-6 week benzodiazepine taper and a 5-week posttaper phase with imipramine, buspirone, and placebo treatment being continued until 3 weeks into the posttaper phase, at which time all patients were switched to placebo for 2 weeks. Benzodiazepine plasma levels were assayed weekly. Benzodiazepine-free status was assessed 3 and 12 months posttaper. RESULTS: Study subjects were long-term benzodiazepine users with an average of three unsuccessful prior taper attempts. The success rate of the taper in this study was significantly higher for patients who received imipramine (82.6%), and nonsignificantly higher for patients who received buspirone (67.9%), than for patients who received placebo (37.5%). The imipramine effect remained highly significant even after the analysis adjusted for three other independent predictors of taper success: benzodiazepine dose, level of anxious symptoms at baseline, and duration of benzodiazepine therapy. CONCLUSIONS: Management of benzodiazepine discontinuation can be facilitated significantly by co-prescribing imipramine before and during the benzodiazepine taper. Daily benzodiazepine dose, severity of baseline symptoms of anxiety and depression, and duration of benzodiazepine use were additional significant predictors of successful taper outcome.     

Double-blind crossover comparison of triazolam and lorazepam in the posthypnotic state

A double-blind crossover study compared the hypnotic effect, daytime carryover, and safety of triazolam 0.5 mg, lorazepam 2 mg, and placebo. The two active drugs were similar in hypnotic effect and superior to placebo. Patients reported more drowsiness upon awakening and more sleepiness in mid-morning and mid-afternoon after nights on lorazepam than nights on triazolam or placebo. The most common side effects--drowsiness, lightheadedness, restlessness, impaired coordination, dizziness, and nausea--were reported three times as often with lorazepam than with triazolam or placebo.     

Benzodiazepines, but not antidepressants or neuroleptics, induce dose-dependent development of tolerance to lorazepam in psychiatric patients

Psychomotor effects of oral lorazepam 3 mg were studied in psychiatric patients stratified into four groups: 1) a group of six patients with no previous use of psychotrophic drugs (NoD), 2) a group of 12 patients treated with antidepressants and/or neuroleptics (PsyD), 3) a group of 10 patients treated with low doses of benzodiazepines (BZs) (lowBZ), and 4) a group of nine patients treated with high doses of BZs (high BZ). Similar objective psychomotor tests and subjective assessments were administered under single-blind conditions to all treatment groups at baseline, after intake of placebo, and after intake of 3 mg lorazepam. Both lorazepam (CGC) and total BZs (bioassay) in serum were assayed. The results demonstrate that treatment with BZs induce dose-dependent development of tolerance to psychomotor effects of lorazepam. Antidepressants and neuroleptics failed to induce cross-tolerance to lorazepam. The rise in serum lorazepam concentrations after lorazepam intake was similar (about 28 micrograms/l) in all treatment groups, suggesting a functional, not dispositional, tolerance. However, the initial learning effect in psychomotor performance was poorer among BZ users than among others.