Efficacy and tolerance: comparative studies with brotizolam and flunitrazepam

WITHDRAWN: Benzodiazepines and related drugs for insomnia in palliative care

This review is out of date, and the original authors are no longer available to update it.

The editorial group responsible for this previously published document have withdrawn it from publication.

4-Phenyl-1-(prop-2-yn-1-yl)-1H-1,5-benzodiazepin-2(3H)-one

4-Phenyl-1H-1,5-benzodiazepin-2(3H)-one reacts in the pres­ence of a concentrated aqueous solution of sodium hydroxide and a quaternary ammonium salt (as catalyst) in benzene (phase transfer catalysis) with propargyl bromide, affording the title benzodiazepine derivative, C₁₈H₁₄N₂O. In the mol­ecule, the mean plane of the propargyl substituent is almost perpendicular with that of the amide group [dihedral angle = 87.81 (8)°]. In the crystal, the molecules are linked by C—H⋯O and C—H⋯N inter­actions.

Benzodiazepines and related drugs for insomnia in palliative care

BACKGROUND

Insomnia, a subjective complaint of poor sleep and associated impairment in daytime function, is a common problem. Currently, benzodiazepines are the most used pharmacological treatment for this complaint. They are considered helpful for occasional short-term use up to four weeks but longer term use is not advised due to potential problems regarding tolerance, dosing escalation, psychological addiction and physical dependence. There is no consensus on their utility in patients with progressive incurable conditions who may require assistance with sleep for many weeks as their condition deteriorates.

OBJECTIVES

To assess the effectiveness and safety of benzodiazepines or benzodiazepine receptor agonists such as Zolpidem, Zopiclone and Zaleplon for insomnia in palliative care.

SEARCH STRATEGY

Several electronic databases were searched including Cochrane PaPaS Group specialized register, Cochrane Library Issue 4, 2001, MEDLINE, EMBASE, BNI plus, CINAHL, BIOLOGICAL ABSTRACTS, PSYCINFO, CANCERLIT, HEALTHSTAR, WEB OF SCIENCE, SIGLE, Dissertation Abstracts, ZETOC and the MetaRegister of ongoing trials. These were searched from 1960 to 2001 or as much of this range as possible. Additional articles were sought by handsearching reference lists in standard textbooks and reviews in the field and by contacting academic centres in palliative care and pharmaceutical companies. There were no language restrictions.

SELECTION CRITERIA

Studies considered for inclusion were randomized controlled trials of adult patients in any setting, receiving palliative care or suffering an incurable progressive medical condition. (For example, cancers, AIDS, Motor Neurone Disease, Multiple Sclerosis, Parkinson's Disease, Chronic Obstructive Pulmonary Disease). There had to be an explicit complaint of insomnia in study participants, diagnosed by any of the three main classification systems (DSM-IV (APA 1994), ICSD (AASD 1990) or ICD (WHO 1992)), or as described in the study if it involved a subjective complaint of poor sleep. Studies had to compare a benzodiazepine or Zolpidem or Zopiclone or Zaleplon with placebo or active control for the treatment of insomnia. Any duration of therapy were considered.

DATA COLLECTION AND ANALYSIS

Abstracts were independently inspected by both reviewers, full papers were obtained where necessary. Where there was uncertainty advice was sought by a third (PW). Data extraction and quality assessments were undertaken independently by both reviewers.

MAIN RESULTS

No randomized controlled trials were identified meeting the a priori inclusion criteria. Thirty-seven studies were considered but all were excluded from the review.

REVIEWER'S CONCLUSIONS

Despite a comprehensive search no evidence from randomized controlled trials was identified. It was not possible to draw any conclusions regarding the use of benzodiazepines in palliative care.

Blood level, metabolism and excretion of [14C]-brotizolam in mice

Blood level, metabolite pattern and excretion of [14C]-brotizolam, a hypnotic drug, were studied in mice following oral administration. [14C]-Brotizolam was rapidly absorbed which was indicated by a Tmax of the blood level of 0.5 h. Radioactive compounds were eliminated from the blood with a half-life of 5.6 h. Total excretion of radioactivity, the renal portion of which was 22.4%, was complete after 4 days. [14C]-Brotizolam was almost completely metabolized. Using TLC, HPLC and radioactivity measurement, the main metabolite in bile, urine and plasma was found to be brotizolam hydroxylated at the methyl group. Other major metabolites were brotizolam hydroxylated at the diazepine ring and a combination of both hydroxylations. In the bile, all metabolites were conjugated. The metabolism of brotizolam in mice is similar to that in dogs, monkeys and man but not in rats.

Brotizolam. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy as an hypnotic

Brotizolam is a new thienotriazolodiazepine derivative with a pharmacological profile similar to that of benzodiazepines. It is indicated for use as an hypnotic in the management of insomnia, although it also has anticonvulsant, antianxiety and muscle relaxant properties in animals. In clinical trials brotizolam 0.125 to 0.5mg improved sleep in insomniacs similarly to nitrazepam 2.5 and 5mg, flunitrazepam 2mg and triazolam 0.25mg, whilst brotizolam 0.5mg was shown to be superior to flurazepam 30mg in some studies. Brotizolam is an effective hypnotic for hospital patients awaiting surgery, in whom it also reduces anxiety. Brotizolam has an elimination half-life of about 5 hours, which is 'intermediate' compared with the shorter-acting hypnotic, triazolam, and longer-acting benzodiazepines. Consequently, it is able to induce sleep without producing early morning rebound insomnia, and can also maintain sleep throughout the night. Brotizolam at dosages below 0.5mg at night usually produced minimal morning drowsiness; no residual impairment of psychomotor performance occurs following dosages within the recommended range of 0.125 to 0.25 mg/kg. No serious side effects have been reported to date and the most frequently observed adverse experiences are drowsiness, headache and dizziness. Mild rebound insomnia may occur in some patients when treatment is stopped. Thus, brotizolam is a useful hypnotic which can be used in patients who have difficulty in falling asleep and also in patients who are troubled by night-time awakenings. Used in the recommended dosage it may be particularly useful for patients in whom daytime impairment of performance is unacceptable.

Brotizolam radioimmunoassay: development, evaluation, and application to human plasma samples

A radioimmunoassay for the determination of the hypnotic agent brotizolam (11) was developed. With this procedure, an antiserum was used which was obtained from rabbits immunized with the hapten 10 (We 934) covalently bound to bovine serum albumin and tritium-labeled brotizolam as the radioligand. Compound 10 represents a structural analogue of brotizolam: the bromine was replaced by a carboxyethyl group. By such manipulation high assay specificity against the primary human metabolites was achieved. The sensitivity limit of the assay was about 100 pg of brotizolam per mL of plasma when 0.1-mL samples were used. The assay showed good accuracy and high precision. Repeated assays after keeping plasma samples frozen for various periods again indicated high precision as well as the stability of the brotizolam molecule under these conditions. Application of the assay to plasma samples of eight subjects who received single oral 0.25-mg doses of brotizolam showed a mean maximum plasma concentration of 4.6 ng of unchanged drug per mL at 0.9 h after administration. The brotizolam plasma concentration declined with a mean elimination half-life of 5.1 h. The pharmacokinetic parameters estimated by RIA agree well with those obtained with other specific brotizolam determination procedures.

Comparative study on the efficacy of and the tolerance to the triazolodiazepines, triazolam and brotizolam

Efficacy of and tolerance to 0.25 mg brotizolam and 0.25 mg triazolam were compared in hospitalised patients (aged 20 to 69 years) with sleep difficulties. Over 6 days there were no differences in efficacy and tolerance. The physicians reported the effectiveness of the drugs as good-to-satisfactory in 88.6% with brotizolam and 92.0% with triazolam. The patients reported with both drugs reduced time to fall asleep, less awakenings, increased duration of sleep and improved condition on awakening.