Effects of brotizolam on the sleep of chronic insomniacs

Discriminative and reinforcing effects of brotizolam in rhesus monkeys

The reinforcing and discriminative stimulus effects of brotizolam, a benzodiazepine-hypnotic, were evaluated in rhesus monkeys. In one experiment, separate groups of monkeys (N = 3 group) were trained to discriminate pentobarbital (10 mg/kg, IG) or d-amphetamine. (0.56-1.0 mg/kg, IG) from saline, in a discrete-trials avoidance/escape paradigm. Pentobarbital (5.6-10 mg/kg), diazepam (1.0-1.7 mg/kg), and brotizolam (0.3-1.7 mg/kg) resulted in 100% drug-lever responding in all three pentobarbital-trained monkeys. In d-amphetamine-trained monkeys brotizolam administration resulted only in saline-lever responding. In another experiment, monkeys were surgically prepared with indwelling intravenous catheters and lever pressing resulted in an injection of 0.1 mg/kg/injection sodium methohexital under a fixed-ratio 10 (FR 10) schedule. Pentobarbital (0.01-0.3 mg/kg/injection) and diazepam (0.003-0.10 mg/kg/injection) maintained responding above saline control levels when substituted for methohexital. Brotizolam (0.001-0.01 mg/kg/injection) resulted in more injections received compared to saline, but fewer injections compared to pentobarbital or diazepam. Thus, results from the present experiment suggest that brotizolam would have pentobarbital-like subjective effects. However, the abuse liability of brotizolam may be lower than that for diazepam.

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.

Alprazolam: effects on sleep and withdrawal phenomena

Alprazolam was evaluated in chronic insomniacs in a 1-mg bedtime dose. The 16-night sleep laboratory protocol included four placebo-baseline nights followed by seven nights of drug administration and five placebo-withdrawal nights. On the first three drug nights (nights 5 to 7), the drug was highly effective in inducing and maintaining sleep with this short-term use. By the end of the one week of administration (nights 9 to 11), however, the drug had lost about 40% of its efficacy. During drug use, one subject reported some difficulty in controlling expression of inappropriate emotions when interacting with others, which suggested the presence of disinhibition. On the third night following drug termination, there was a significant increase in sleep difficulty above baseline levels (rebound insomnia). This worsening was of comparable magnitude to the peak improvement of sleep with drug administration. Thus, the clinical utility of alprazolam when administered to insomniac patients appears to be limited because of a relatively rapid development of tolerance and possible disinhibitory reactions during drug use and the occurrence of rebound insomnia following withdrawal.