[Comparative evaluation of the hypnotic drugs under conditions of brain injury]

The effect of hypnotic drugs on the brain stability with respect to complete ischemia posttraumatic convulsive reactions and hypoxia has been studied in animals with model brain injury. It is established that zopiclone exhibits pronounced hypnotic effect during the first and second week after brain injury, while nitrazepam, zolpidem, and melaxen are effective in the first week. The neuroprotective effects of zopiclone and zolpidem are more pronounced than those of melaxen and nitrazepam.

Notable pink excreta and severe myocardial suppression in superwarfarin (difethialone) intoxication

Patients rarely consult physicians before developing coagulopathy or bleeding in most reported cases of superwarfarin intoxication. A 57-year-old woman ingested red-dyed pellets of anticoagulant rodenticide containing difethialone and warfarin as well as tablets of nitrazepam. Although she presented to the hospital in a comatose state, notable pink-colored excreta hinted at the consumption of anticoagulant rodenticide, which led to the early diagnosis of superwarfarin intoxication. Supplementation of large doses of intravenous and oral vitamin K successfully prevented coagulopathy and bleeding. On the other hand, temporary and reversible myocardial suppression was extremely severe, and required the introduction of percutaneous cardiopulmonary support.

Modeling cumulative dose and exposure duration provided insights regarding the associations between benzodiazepines and injuries

BACKGROUND AND OBJECTIVES

Accurate assessment of medication impact requires modeling cumulative effects of exposure duration and dose; however, postmarketing studies usually represent medication exposure by baseline or current use only. We propose new methods for modeling various aspects of medication use history and employment of them to assess the adverse effects of selected benzodiazepines.

STUDY DESIGN AND SETTING

Time-dependent measures of cumulative dose or duration of use, with weighting of past exposures by recency, were proposed. These measures were then included in alternative versions of the multivariable Cox model to analyze the risk of fall related injuries among the elderly new users of three benzodiazepines (nitrazepam, temazepam, and flurazepam) in Quebec. Akaike's information criterion (AIC) was used to select the most predictive model for a given benzodiazepine.

RESULTS

The best-fitting model included a combination of cumulative duration and current dose for temazepam, and cumulative dose for flurazepam and nitrazepam, with different weighting functions. The window of clinically relevant exposure was shorter for flurazepam than for the two other products.

CONCLUSION

Careful modeling of the medication exposure history may enhance our understanding of the mechanisms underlying their adverse effects.

Electroencephalographic properties of zaleplon, a non-benzodiazepine sedative/hypnotic, in rats

The encephalographic (EEG) properties of zaleplon were investigated in comparison with those of other sedative hypnotics in conscious rats with chronically implanted electrodes. The oral administration of zaleplon (0.25-1.0 mg/kg), triazolam (0.0625-0.25 mg/kg), zopiclone (1.0-4.0 mg/kg), brotizolam (0.0625-0.25 mg/kg), and nitrazepam (0.125-0.5 mg/kg) lengthened the total sleep in a dose-dependent manner. On distribution of sleep-wakefulness stages, zaleplon, in particular, increased the slow wave deep sleep (SWDS), whereas triazolam, brotizolam, and nitrazepam increased the slow wave light sleep (SWLS) in a dose-dependent manner. Zopiclone significantly increased the SWDS at a dose of 2 mg/kg and both the SWLS and the SWDS at a dose of 4 mg/kg. All tested hypnotics caused no influence on fast wave sleep (FWS) at doses tested. The appearance of the sleep-inducing activity of zaleplon was more rapid than those of any compounds tested, and zaleplon significantly increased the relative EEG power density in the delta frequency band over that of triazolam at 20 and 30 min after the administration in the spectral analysis. Therefore, the present findings suggest that the non-benzodiazepine zaleplon can be expected to exhibit high practical potential as a hypnotic and is characterized by an increase in SWDS with rapid onset of hypnotic action.

Short-term nonhormonal and nonsteroid treatment in West syndrome

PURPOSE

West syndrome (WS) is considered an age-dependent epileptic encephalopathy and also a particular type of electrical epileptic status. Short-term hormonal or steroid treatment of WS with good efficacy is reported in the literature. The aim of this retrospective multiinstitutional study was to evaluate the early discontinuation of nonhormonal and nonsteroid treatment for WS.

METHODS

Twenty-two WS cases in which treatment was discontinued after a maximum of 6 months, were collected. Inclusion criteria were the presence of typical EEG hypsarrhythmia (HY) and video-EEG recorded epileptic spasms. Exclusion criteria were the presence of partial seizures or other seizure types before spasm onset. The patients were treated with vigabatrin (VGB) in 19 cases and nitrazepam (NTZ) in three. The dose range was 70-130 mg/kg/day for VGB and 0.7-1.5 mg/kg/day for NTZ. The drug was discontinued if spasms stopped and HY disappeared after a mean treatment period of 5.1 months (range, 3-6 months). All patients underwent repeated and prolonged awake and sleep video-EEG, both before and after drug discontinuation.

RESULTS

Cryptogenic (15) and symptomatic (seven) WS patients were included. All the symptomatic cases had neonatal hypoxic-ischemic encephalopathy. The mean age at spasm onset was 5.5 months (range, 3-7 months; median, 6). The interval between spasm onset and drug administration ranged from 7 to 90 days (mean, 23 days; median, 20). The interval between drug administration and spasm disappearance ranged from 2 to 11 days (mean, 6 days; median, 6 days). The interval between drug administration and HY disappearance ranged from 3 to 30 days (mean, 9 days; median, 10 days). Drugs were stopped progressively over a 30- to 60-day period. Follow-up ranged from 13 to 50 months (mean, 26 months; median, 22 months). None of our cases showed spasm recurrence.

CONCLUSIONS

Our data show that successful nonhormonal and nonsteroid treatment can be shortened to a few months without spasm recurrence in patients with cryptogenic or postanoxic WS.

Nitrazepam for the treatment of Lennox-Gastaut syndrome

Lennox-Gastaut syndrome is a severe childhood epileptic syndrome with encephalopathy and multiple seizure types, which are often intractable to treatment. Most of these children will ultimately become mentally retarded and dependent on others for their daily care. Antiepileptic drugs are the mainstay of treatment, however, no particular drug is entirely effective. Apart from the use of antiepileptic drugs, nonpharmacologic treatments are also considered (i.e., callosotomy, ketogenic diet, and vagus nerve stimulation), which have proven to be partially effective. We prospectively studied 14 children (11 months-8 years of age) with medication-resistant Lennox-Gastaut syndrome, being treated with nitrazepam (open-label compassionate protocol). We compared the 1-month baseline seizure frequency with the median seizure rate reduction during the first 12 months of treatment with nitrazepam. The median seizure rate reduction during the first 12 months of treatment with nitrazepam was 41% (P = 0.001), with more than 50% seizure reduction in 60% of patients. Two patients became seizure free, five patients demonstrated at least 50% reduction in seizure rates, six patients had at least 25% seizure rate reduction, and one patient did not respond. No patient had any serious adverse effects. Side effects included sedation in six children (40%) and drooling in nine patients (60%).

[Gabitril as an additive drug in therapy of intractable epileptic seizures in children]

Tiagabine (Gabitril, Sanofi Synlhelabo) new antiepileptic drug was used in add-on therapy in 25 children with resistant partial complex and secondary generalized seizures. Treatment was carried out in children aged 4-17 years with low dose escalation from 5 to 45 mg/day, in three doses until good clinical effects were obtained. In 3 patients aged 4 years, in 11 children aged 5-12 years and in 11 children aged above 17 years Gabitril was used. Follow up period was 8-10 months. Frequency of epileptic seizures before implementation of Gabitril treatment, even during polytherapy with 2 or more antiepileptic drugs was several to hundred per day (status epilepticus was observed in 2 children with Rasmussen syndrome). During the observation 5 children became seizure free, in 11 patients reduction in seizures frequency above 50% was observed and in 9 children effects of treatment were not good enough. Gabitril was well tolerated, and any adverse events were observed in add-on therapy. Preliminary observation and good results of add-on therapy with Gabitril are positive. Drug is safe and generally well-tolerated with good effects at add-on therapy in 64% children with resistant partial complex and secondary generalized seizures.

[Influence of co-administered antiepileptic drugs on nitrazepam tolerance in mice]

In the treatment of epilepsy, benzodiazepines are often administered in combination with other antiepileptic drug (s) because of the development of tolerance. In this study, the influence of concurrently administered antiepileptic drugs on tolerance to the anticonvulsant action of the nitrazepam (NZP) was studied using an animal tolerance model. Mice were given vehicle, NZP alone or NZP concurrently with one of six antiepileptic drugs (carbamazepine CBZ, phenytoin PHT, zonisamide ZNS, vigabatrin VGB, lamotrigine LTG, or flunarizine FNR) twice daily for 5 days. Tolerance was assessed by the ability of NZP to prevent pentylenetetrazol-induced clonic convulsions. Tolerance developed in mice treated with NZP alone, NZP plus CBZ, PHT, ZNS, VGB or LTG. On the other hand, mice receiving NZP + FNR showed no tolerance; there was no significant difference in seizure frequency between the vehicle group and NZP + FNR group. These data suggest that co-administration of FNR but not CBZ, PHT, ZNS, VGB or LTG may delay if not prevent development of tolerance to the anticonvulsant action of benzodiazepines.

Benzodiazepine effects on memory tests: dependence on retrieval cues?

Acute effects of oral flunitrazepam (0.5 and 1 mg), nitrazepam (5 and 10 mg) and placebo were assessed on direct (free recall of words and prose, stem-cued recall) and indirect (stem and fragment completion) memory tasks. Fifty health volunteers took part in this double-blind, independent group study. The relative effects of the two benzodiazepines (BZs) on memory revealed a different pattern from their effects on alertness, indicating that their amnesic effects are not totally secondary to their sedative effects. The higher dose of flunitrazepam impaired free recall of words and prose but not cued recall, while neither drug affected the two indirect tasks. Differences in drug effects on the direct and indirect memory tasks were discussed in terms of resource demands of the various tests. We conclude that whether BZs impair performance on memory tasks depends more on the cues given at retrieval than the retrieval instructions (direct/indirect). The implications for this in terms of BZ amnestic effects are drawn out for contextual encoding deficits induced by BZs.

Pharmacotherapy of transient insomnia related to night work

Shiftworkers working on the night shift transpose their sleeping hours to the time of day which is inconvenient for sleep because of the endogenous circadian rhythm sleep wakefulness, the circadian rhythms of other body functions and the environmental schedule. As a result of this, a certain number of workers suffer from insomnia. This study aimed at examining the effects of two hypnotic agents with different elimination times on sleep disturbances which follow night shift work. Three groups of shiftworkers took zopiclone, nitrazepam and placebo capsules during a week of work on the night shift repeating it three times so that each week of capsule taking was separated from the next by a three-week break. In the two groups on hypnotics total length and efficacy of main sleep improved as did the efficacy of all day sleeps at the very beginning of the week, and these sleep characteristics persisted throughout the week. In contrast, in the group which took a placebo sleep was shorter and loss efficacious at the beginning but improved towards the end of the week. There was no negative effect of hypnotics on the shiftworker's mood after waking up. To an extent, the hypnotics proved to be useful for periodical pharmacological improvement of the length and efficacy of day sleep after night work in the slowly rotating shift system.

Nitrazepam for refractory infantile spasms and the Lennox-Gastaut syndrome

Infantile spasms and the Lennox-Gastaut syndrome are considered to be age-specific pediatric epileptic syndromes and together constitute a significant percentage of medically resistant seizures in childhood. Twenty children, ages 4 to 28 months (median, 12 months), with medically refractory infantile spasms or the Lennox-Gastaut syndrome, were treated with the investigational benzodiazepine nitrazepam in an open-label study. Daily dosage of nitrazepam ranged from 0.5 to 3.5 mg/kg, with a median dosage of 1.5 mg/kg, divided into two doses per day. Side effects included pooling of oral secretions (12 children) and sedation (six children); however, no serious side effects were seen. Responses to nitrazepam were as follows: five complete responses (cessation of all seizures), seven partial responses (greater than 50% reduction of seizures), and eight with no response. Median duration of response was 9 months (range, 4 to 16 months) in children with infantile spasms and 14 months (range, 8 to 26 months) in children with the Lennox-Gastaut syndrome. Nitrazepam is an effective anticonvulsant in this small cohort of children with medically refractory infantile spasms and the Lennox-Gastaut syndrome, resulting in a 25% response rate and only modest side effects.

Male reproductive toxicity study of nitrazepam in rats

The main focus of this study is the optimal administration period concerning toxic effects on male fertility in rats. To assess functional and morphological changes induced in the testis by nitrazepam, male rats were administered the drug at doses of 0, 20, 40 or 80 mg/kg during pre-mating periods of 2, 4 or 9 weeks and then the 2 weeks of mating. At the end of the administration period the animals were sacrificed and sperm number, motility, abnormalities and histopathological changes in the testis were examined. Decreases in testis weight, epididymis weight, number of sperm in the testis and sperm motility were observed in the 40 and 80 mg/kg sections of the 2, 4 and 9 week pre-mating treated groups. Mating with untreated females revealed no adverse effects on copulation rate in any group; however, a remarkable decrease in pregnancy rate was noted in the 80 mg/kg section of the 2, 4 and 9 week treated groups. On histological examination, various degrees of localized necrosis in the seminiferous epithelium and Leydig cell hyperplasia were observed in the testis. No clear changes were observed in the 20 mg/kg section of the 2 week pre-mating administration group, but at the 4 week time point, necrosis of spermatogenic cells began to appear. The primary morphological event was evident in spermatocytes with necrosis of the cytoplasm observed from 4 weeks after administration of nitrazepam, although sperm motility and sperm head counts were unaffected. From these findings, examination of sperm characteristics and histopathological changes in the testis are important parameters for evaluation of drugs inducing testicular damage. We conclude that a 4 week administration period is sufficient to detect effects of nitrazepam on male fertility.

Potential parameters of male reproductive toxicity: reproductive performance, histopathology and sperm evaluation in SD rats given nitrazepam

The present study was designed to elucidate the correlation between findings from reproductive performance testing and those from histopathological examination of the testis and sperm analysis in rats given a benzodiazepine derivative, nitrazepam, for 2 and 4 weeks. The mechanisms of toxicological action of nitrazepam on the male reproductive organs were also investigated. Nitrazepam was given orally to Sprague-Dawley male rats (6-week-old) at a daily dose of 80 mg/kg for 2 weeks or at daily doses of 20, 40 or 80 mg/kg for 4 weeks. Treated males were mated to examine reproductive performance with untreated females after each dosing period, and after 4 and 9 week of recovery periods. Necropsy was performed for histopathological examination of the testis and epididymis and for sperm analysis after each dosing period and the final mating trial (total of 11 weeks recovery). In the findings from reproductive performance testing, significant decrease in the fertility index was observed in the 80 mg/kg group even after 2 weeks dosing and thereafter until 4 weeks recovery, though the mating index did not significantly differ from that of controls through the experiment. In the histopathological examination and sperm analysis, testicular signs of toxicity, decrease in number of sperm heads in the testis and increase in number of sperm with abnormal heads in the seminiferous tubules were noted in the 80 mg/kg group after 2 weeks dosing and in the 40 and 80 mg/kg groups after 4 weeks dosing. Concentrations of plasma testosterone and content of testis testosterone in nitrazepam-treated groups were not significantly different from those of controls. Plasma FSH concentration was significantly elevated in the 80 mg/kg group through the experiment, although significant elevation of plasma LH was observed only after 2 weeks dosing. These results indicate that histopathological examination is the most reliable approach to detect male reproductive adverse effects induced by nitrazepam rather than using parameters from mating trials. The four-week-dosing period is appropriate for their detection. Hypospermatogenesis induced by nitrazepam is suggested to be caused by direct action of nitrazepam on germ cells and/or Sertoli cells rather than by indirect action through inhibition of testosterone secretion.

Interaction between erythromycin and nitrazepam in healthy volunteers

Interaction between erythromycin, a strong inhibitor of CYP3A4, and nitrazepam, a long-acting benzodiazepine, was investigated in a double-blind and randomized cross-over study of two phases. Ten healthy volunteers received erythromycin (500 mg x 3) orally or placebo for 6 days. On the fourth day they were given a challenge dose of 5 mg nitrazepam. Plasma samples were collected and psychomotor effects were measured during 42 hr after intake of nitrazepam. There was a statistically significant pharmacokinetic interaction between erythromycin and nitrazepam. Erythromycin increased the area under the nitrazepam concentration-time curve by 25% (P < 0.05) and the peak concentration by 30% (P < 0.05). The concentration peak time of nitrazepam was shortened by over 50% (P < 0.05). The elimination half-lives did not change. Accordingly, as far as the metabolism of nitrazepam is concerned, erythromycin does not cause any major changes in the metabolism of nitrazepam. In psychomotor performance only minor differences were seen. It is concluded that the interaction between erythromycin and nitrazepam is of little clinical significance.

Benzodiazepine prescribing and withdrawal for 3234 patients in 15 general practices

Benzodiazepines are still widely prescribed in general practice, despite repeated warnings about the problems associated with their use. Other studies have shown that a variety of interventions can reduce prescribing, but these have been restricted to relatively few general practices or patients. We co-ordinated an audit of benzodiazepine prescribing and withdrawal in 15 practices caring for 87,900 patients across a district. In total 3234 patients (37 per 1000 registered patients) were discovered to be taking the drugs at the start of the programme, and 16% of these people stopped taking the drugs by the conclusion of the audit 8 months later. There was no relation between success at benzodiazepine cessation and initial levels of prescribing, nor with practice size. Younger patients were significantly more likely to stop benzodiazepines than those over the age of 65.

Nitrazepam in patients with sleep apnoea: a double-blind placebo-controlled study

We wanted to assess whether benzodiazepines worsen sleep apnoea, since their use in such patients has been controversial. Fourteen male patients with mild to moderate obstructive sleep apnoea were investigated in a placebo-controlled, double-blind study evaluating the influence of nitrazepam (NIT) on apnoea frequency and severity. Each patient was given oral nitrazepam 5 or 10 mg, or corresponding placebo, in a randomized order on three separate nights. Wash-out time was one week. A complete sleep study was undertaken at each study night. Eleven patients completed the study. Although there were individuals with marked variability in apnoea index between the three study nights, there was no significant change in apnoea index or minimum arterial oxygen saturation with any of the two nitrazepam dosages studied. Only 3 out of 11 patients had a higher apnoea index after both nitrazepam doses compared to placebo, and in these patients the increase in sleep-disordered breathing was of marginal clinical significance. Nitrazepam caused a modest increase in total sleep time and a decrease in rapid eye movement (REM) sleep. These results demonstrate that nitrazepam does not worsen sleep apnoea in patients with mild to moderate sleep apnoea. The previously reported sleep apnoea promoting effects of benzodiazepines may be restricted to a small subgroup of patients with sleep-disordered breathing.

West syndrome associated with porencephaly

A 3-year-old boy with West syndrome who was shown to have a cystic lesion on magnetic resonance imagings underwent surgical treatment. He had been initially managed with several antiepileptic drugs, but abnormalities on electroencephalography (EEG) persisted. Histological examination of the cystic wall obtained during surgery suggested porencephaly. Two years and 2 months later the child remained seizure-free and his EEG remarkably improved.

Seizures with clonazepam: discontinuation and suggestions for safe discontinuation rates in children

Clinical characteristics of clonazepam (CZP) discontinuation seizures were clarified from 17 patients who developed seizure exacerbation after rapid discontinuation, including abrupt discontinuation, reduction, or replacement with nitrazepam (NZP). Safe discontinuation rates of CZP were estimated by comparing these patients with 23 patients without CZP discontinuation seizures. The seizures consisted of status epilepticus or frequent attacks of generalized tonic-clonic seizures (GTC) or non-GTC, and the first attack of GTC. Incidence did not differ significantly between CZP-effective cases and CZP-ineffective cases at discontinuation. The reasons for abrupt discontinuation included adverse effects, insufficient efficacy, difficulty in taking CZP owing to pneumonia, or carelessness of the doctors or the families. Seizure exacerbation occurred 1-6 days after CZP discontinuation. Most of the problems improved with readministration of the original or smaller dosages of CZP or of NZP in an amount threefold or more greater than the original CZP dose. Safe discontinuation rates were estimated to be < or = 0.04 mg/kg for abrupt discontinuation, < or = 0.04 mg/kg/week for reduction, and replacement with NZP of 2.5 or more times the original amount of CZP. These safe discontinuation rates were prospectively confirmed by 84 cases of CZP discontinuation in 54 other patients, and no seizure exacerbation occurred with these discontinuation rates.

Nitrazepam-induced cricopharyngeal dysphagia, abnormal esophageal peristalsis and associated bronchospasm: probable cause of nitrazepam-related sudden death

Nitrazepam was used in the treatment of resistant myoclonic epilepsy in 38 children. After the occurrence of nitrazepam-associated swallowing incoordination, high-peaked esophageal peristalsis and related bronchospasm in one patient, we initiated a prospective study of esophageal manometry using a station pull-through technique with a pediatric 4-channel continuous perfusing system. Three more patients were found to have delayed cricopharyngeal relaxation and high-peaked esophageal peristaltic waves. The initial patient developed severe respiratory distress and bronchospasm necessitating ventilatory support while on nitrazepam and improved dramatically with subsequent normal manometric study following nitrazepam discontinuation. Nitrazepam was reintroduced for its anticonvulsant and cognitive benefits and was tolerated at a reduced dosage. We postulate a central nervous system effect of nitrazepam promoting parasympathetic overactivity or vagotonia which can cause potentially fatal respiratory distress. Care must be exercised in nitrazepam use and esophageal manometry may be helpful in defining patients at greater risk for sudden death.

Infantile spasms. A retrospective study of 105 cases

This paper is a summary of our observations on 105 cases of infantile spasms. The age of onset was around six months after birth, but the patients came for treatment mainly about one year after onset. Fever of unknown cause, asphyxia, birth injury, infection of the central nervous system, tuberous sclerosis, phenylketonuria and recent immunization etc. were complained. Clinically, it is characterized by head nodding, mental retardation, myoclonic jerks and various neurologic deficits. EEG findings showed classical or modified arrythmia or other epileptiform patterns. About one third of 22 cases examined had abnormal brain stem auditory evoked potentials. Among 42 patients who underwent CT scanning before ACTH treatment, 18 were normal and 7 abnormal; during ACTH treatment 3 normal and 4 abnormal; after completion of treatment, 4 normal and 6 abnormal, suggesting no further atrophy of the brain. Examination of trace elements of the hair by particle-induced X-ray emission (PIXE) method in 23 patients revealed a significant difference in lead, calcium and zinc contents between patients and 101 controls, but no statistical difference in iron and copper contents between the two groups. Sodium valproate, prednisone and ACTH appear to be effective in the treatment of infantile spasms. Eight patients fully recovered, and they can go to school without difficulty. Many patients derived various degrees of improvement to the satisfaction of their parents. Two patients were still amented and often attacked by myoclonus. The effects, side effects of these drugs, and the possible pathogenesis were discussed.

[Daytime sedation measured after intake of nitrazepam and lorazepam, respectively, as hypnotics for 10 days]

A prospective double-blind cross-over investigation was undertaken among 46 geriatric patients (62-92 years) in which either 5 mg nitrazepam or 1 mg lorazepam were administered as hypnotics for two periods of ten days. No significant differences were observed in the quality of sleep but the objective psychomotor tests and the patients' subjective experience of hang-overs showed that there were significant differences in the frequencies of side effects in favour of lorazepam. It is concluded that daytime sedation after repetitive administration of a benzodiazepine preparation depends upon the half-life and that side effects are revealed better by psychomotor tests than by intellectual, cognitive tests and that lorazepam should be given preference to nitrazepam as a hypnotic for elderly patients.

[Direct compression nitrazepam tablets]

Tablets of nitrazepam were made by direct compression. The influence of different dry binders and other adjuvants on the physical parameters of the tablets and their texture (scanning electron microscope: SEM) were examined. Changes in the physical parameter can be explanded if the texture is known.

Febrile seizures

The definition, prevalence, characteristics, genetics, and causes of febrile seizures are discussed in this article. Acute management is outlined, including indications for lumbar puncture and treatment of the febrile child who is continuing to seize. The usefulness and limitations of the EEG are noted. Factors influencing the likelihood of further febrile seizures and the risk of later epilepsy are reviewed. The pros and cons of continuous and intermittent drug therapies for febrile seizure prophylaxis are summarized. A new double-blind randomized study of intermittent oral diazepam for the prevention of febrile seizure recurrences is described.

The psychomotor effects of single and repeated doses of hypnotic benzodiazepines

Benzodiazepine hypnotics are used for short periods in low doses in healthy people when stressed and in patients with insomnia. This study examined psychomotor impairment in healthy young males and females after 1 and 7 nights of flunitrazepam (1 mg), nitrazepam (2.5 mg) and temazepam (10 mg). There were substantial inter-individual variations. Results showed that no drug significantly affected psychomotor performance at these doses after single or repeated administration. The number and severity of side-effects were significantly greater after the first night with temazepam and 7 nights with nitrazepam, although this may reflect a statistical artefact rather than a significant clinical finding. The difficulties in performing adequately controlled psychopharmacological studies at low doses are highlighted. Given the large intra- and inter-subject variances, small drug effects would necessitate large sample sizes (21 to 600 subjects at the 95% level of chance of detection) depending on the variable. The study suggests there is minimal impairment with low dose hypnotic drugs and a need to individualize treatment.

Zopiclone and nitrazepam: a multicenter placebo controlled comparative study of efficacy and tolerance in insomniac patients in general practice

The efficacy and tolerance of zopiclone were compared with nitrazepam and placebo in a multicenter double-blind parallel-group study in insomniac patients. Following a 7-day placebo washout period, 99 patients (age range 20 to 69 years) received oral capsules of 7.5 mg zopiclone or 5 mg nitrazepam or placebo for 2 weeks. During the fourth week all patients received placebo treatment. Sleep assessments by the patients showed that, compared with placebo, zopiclone and nitrazepam improved all sleep measures of efficacy from the first night and that effectiveness was maintained throughout treatment. The physicians global assessment of efficacy also favored zopiclone and nitrazepam over placebo treatment. Subjective morning drowsiness during treatment was significantly less for zopiclone than for either nitrazepam or placebo and represents a clear advantage for ambulatory patients. No rebound insomnia was evident during a 7 day post-treatment withdrawal period for either zopiclone or nitrazepam. Tolerance was good for all treatments.

Zopiclone versus nitrazepam: a double-blind comparative study of efficacy and tolerance in elderly patients with chronic insomnia

A randomized, double-blind, comparative trial of zopiclone versus nitrazepam was conducted in 74 geriatric chronic insomniac patients. Following a 7-day wash-out period, two parallel groups, successively received a placebo for 7 days, then either 7.5 mg zopiclone or 5 mg nitrazepam for another 7-day period. Efficacy on sleep was assessed by a sleep analogue scale and the Spiegel Sleep Questionnaire, residual effects by psychometric tests and tolerance by a standardized question, as well as by clinical and laboratory tests. Zopiclone and nitrazepam were more active than placebo on all tests of efficacy. In contrast with nitrazepam, zopiclone was devoid of effect on neurological function. In addition, the condition on awakening was better with zopiclone.

Carbamazepine and benzodiazepines in combination--a possibility to improve the efficacy of treatment of patients with 'intractable' infantile spasms?

Therapeutical efforts in epilepsies with infantile spasms (IS) often show unsatisfying results, especially if neurological impairments are found. In a clearly negatively selected group of 24 children with IS and 10 patients with symptomatic myoclonic-astatic epilepsies--pretreated without success with ACTH and/or benzodiazepines (BDZ) alone or combined with other anticonvulsants--we tried a two-drug therapy of BDZ with carbamazepine (CBZ). Dosage of both drugs was within the usual range. In a follow-up period of 1-5 years, 8 of the IS patients and 4 of those with myoclonic-astatic seizures became seizure-free; furthermore, 6 children showed a marked reduction in their seizure frequency: 3 more than 80%, 3 more than 50%. Besides the fact that the patients did not develop a so-called escape-phenomenon--as often seen in therapy with benzodiazepines--they also showed fewer and less intensive side-effects. Without optioning for antiepileptic polytherapy in general, we conclude that in cases of "intractable" IS the combination of BDZ with CBZ might be more successful than the single drug. To confirm these preliminary findings further controlled studies have to be carried out.

Alterations in the thermic response to chlorpromazine in rats exposed prenatally to central nervous system depressants

The thermic response to acute administration of chlorpromazine (5 mg/kg, i.p.) was assessed in rats exposed prenatally to haloperidol (0.1 mg/kg), phenobarbital (10 mg/kg), nitrazepam (2 mg/kg), propylene glycol (1 ml/kg) or saline, once daily from days 1-21 or 15-21 of gestation. The response in all animals was tested only once. The administration of chlorpromazine to 8- or 13-week-old male and female rats treated with saline (1-21 d) induced marked hypothermia for a 6-hr period of observation. Male and female rats treated with haloperidol (1-21 d) showed a delayed hyperthermic response to chlorpromazine at 8 weeks of age; the males showed an increase in rectal temperature at 3 hr and the females from 3 to 6 hr. Thirteen-week-old males but not females treated with haloperidol (1-21 d) showed a hyperthermic response to chlorpromazine during the first 2 hr. Eight-week-old male and female rats treated with phenobarbital (1-21 d) showed hypothermia, whereas 13-week-old male rats of another group treated with phenobarbital (1-21 d) showed significant hyperthermia after the administration of the chlorpromazine. The hypothermic response of the rats treated with nitrazepam (1-21 d) to chlorpromazine was similar to that in the vehicle (propylene glycol)-treated controls. The male rats treated with phenobarbital (15-21 d) responded to chlorpromazine with significant hyperthermia from 30 min to 1 hr. There was no alteration in thermic response to chlorpromazine in rats born to mothers treated with one tenth of the dose of phenobarbital, haloperidol or nitrazepam.(ABSTRACT TRUNCATED AT 250 WORDS)

Residual effect of single and repeated doses of midazolam and nitrazepam in relation to their plasma concentrations

Twelve healthy volunteers were given either midazolam 15 mg or nitrazepam 5 mg for 7 consecutive days in a randomized cross-over trial. Self-assessment of sleep, mood or condition on awakening and adverse effects was performed, and the volunteers underwent evaluation of psychomotor performance. Hypnotic effect, judged by the classical sleep variables, showed that the drugs were more or less equal and were superior to placebo. Nitrazepam consistently produced an impaired condition on awakening and also clearly displayed a spectrum of adverse motor effects. Motor tests revealed impairment induced by both drugs, but, in the midazolam group the effect subsided during the trial period. Both drugs had a significant effect on memory, midazolam appearing to perturb certain memory functions to a greater extent than did nitrazepam. The residual plasma concentration of midazolam 11 h after treatment correlated well with the scores obtained in several of the psychomotor tests, whereas plasma nitrazepam levels were not related to performance in any subtest. When discontinued neither drugs, induced any rebound phenomenon. However, the adverse effects of nitrazepam appeared to be carried over into the adjacent placebo period.

Effects of repeated dose nitrazepam and lormetazepam on psychomotor performance in the elderly

The daytime psychomotor performance of 12 healthy subjects of mean age 81.4 years was examined in a double-blind crossover study following single and repeated nightly doses of nitrazepam 5 mg, lormetazepam 1 mg, and placebo. Accuracy of performance on the Gibson spiral maze was unaffected by both drugs. On a reciprocal tapping task, speed was similarly unaffected. However, while neither drug significantly impaired accuracy on reciprocal tapping after the first dose, nitrazepam, but not lormetazepam, significantly reduced overall accuracy after seven consecutive doses, an effect consistent with drug accumulation.

Changes in hypnotic usage in residential homes for the elderly: a longitudinal study

The use of hypnotic drugs in 25 local authority homes for the elderly was recorded on a 1-day point prevalence study following a 6-mth monitoring programme involving all new admissions. From a total population of 1114 residents 390 (35%) were taking hypnotics on the night of the survey, showing a slight increase from similar surveys carried out in 1980 and 1981. The proportion of residents receiving hypnotics within each home varied from 0.0 to 61.8%. Correlation with levels of usage in the previous surveys was low, suggesting that pattern of hypnotic usage may change considerably over time within individual homes. Of the 156 residents who were admitted as permanent residents during the 6-mth period preceding the survey, 56 (35.9%) had been taking hypnotics on admission. Both the results of the drug monitoring programme and the survey show an association between hypnotic usage and source of admission: residents admitted from hospital being more likely to be taking sleeping tablets. A considerable change was found in the type of hypnotic currently prescribed with an increased preference being shown for short half-life hypnotics. A higher proportion of residents also were prescribed lower doses of hypnotics than previously, suggesting an increased awareness of the risks associated with hypnotic use in the elderly.

Intermittent treatment of febrile convulsions with nitrazepam

Intermittent oral or rectal administration of diazepam for the prophylactic treatment of febrile convulsions has given results comparable to the continuous use of phenobarbital while limiting side effects and risks of toxicity. Since we believe that nitrazepam is a better anticonvulsant than diazepam, we performed a study to evaluate the effectiveness of this medication in the prophylactic treatment of febrile convulsions. Nitrazepam was given only when the children had fever and almost exclusively in children with a high risk of recurrence (less than 12 months of age at first convulsion; atypical convulsion; one or several previous convulsions). Thirty one children with a high risk of recurrence received nitrazepam. The rate of recurrence in this group was 19.3% after a follow-up of 16 months, compared to 45.8% in 24 children who also had a high risk of recurrence but in whom the parents refused the medication or gave it inadequately (p less than 0.05). Fifty one children with a low risk of recurrence also were evaluated and followed for at least 12 months (mean 15.4 months). Six were treated with nitrazepam, mostly because of parental anxiety, and none had a recurrence; of the 45 untreated children in this group, 6 (13.6%) had another convulsion. These results show the efficiency of nitrazepam in the prophylactic treatment of febrile convulsions.

Low doses of brotizolam and nitrazepam as hypnotics in the elderly

0.125 mg brotizolam and 2.5 mg nitrazepam proved to be equipotent in promoting and maintaining sleep in 29 elderly patients used to long-term hypnotics. These drugs were superior to placebo and they were excellently tolerated. The drugs were administered in a random order, double-blind, for 7 nights each.

Development of tolerance to benzodiazepines. I. Changes in the systems of central nervous system neurotransmitters during long-term administration of nitrazepam

A purpose of the study was determination of the relationships between the brain levels of neuro-mediators: noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5-HT) and gamma-aminobutyric acid (GABA) and the development of tolerance to the sedative and anticonvulsive action of Nitrazepam. It was found that during tolerance development the GABA level increased in the cerebral tissue and changes appeared in the activity state of the serotoninergic system.

A double-blind controlled multicenter trial comparing butriptyline with amitriptyline

77 primary depressive in-patients aged 18-70 years (mean = 46/47 years) were assigned randomly to experimental and control groups and treated in double-blind conditions in ten centers. Butriptyline and amitriptyline were both administered with an identical increasing schedule, up to 150 mg daily in the first week and a flexible schedule for the last 3 weeks of trial. Mean daily doses were 145 mg butriptyline and 142 mg amitriptyline after 2 weeks, and 77.5 mg amitriptyline and butriptyline after 4 weeks. Nitrazepam (5-10 mg) and haldol (5 mg) were also allowed, only if necessary. Symptomatology and antidepressant efficacy were assessed using the rating scales of Hamilton, Overall, BPRS, CGI and a side effect checklist. After initial comparison of the two treatment groups, the results showed that the antidepressant effects were significantly better with butriptyline on the number of dropouts, on the total score and on the following factors of the Overall Depression Scale: depression, guilt, anxiety, somatization and somatic complaints. Frequency of haldol prescription was significantly lower with butriptyline than with amitriptyline. The overall frequency of side effects and of autonomic symptoms did not differ in the two groups. The effects on other parameters (hematological and biochemical variables, ECG and EEG) were similar for both drugs. In conclusion, butriptyline has the same indications as amitriptyline but shows a better antidepressant efficacy at the same dosage.

The effect of digoxin on the response to lithium therapy in mania

Patients suffering from manic-depressive psychosis, manic type (ICD 296.0), were treated with lithium carbonate and randomly allocated to two groups, one received digoxin and the other matching placebo for 7 days. Severity of mania was rated by psychiatrists on the Manic Rating Scale and Analogue Line on days 0 and 7 and by nurses daily on the Hargreaves Rating Scale, Psychotic Rating. Fourteen patients received digoxin and lithium carbonate and 14 patients received placebo and lithium carbonate. Improvement in the placebo lithium group was significantly greater than that in the digoxin lithium group. This trial suggests, therefore, that the effect of inhibition of membrane cation carrier is to reduce the response to lithium. This result is in keeping with our hypothesis that an increase in Na-K ATPase is essential to the therapeutic effect of lithium carbonate. It does not, however, exclude the possibility that the observations resulted from the inhibition by digoxin of lithium entry into the brain.

Comparison of nitrazepam 5 mg with triazolam 0.5 mg in young psychiatric insomniac inpatients. Double-blind single night cross-over study

Sixty young male patients with insomniac disorders were treated with nitrazepam 5 mg or triazolam 0.5 mg in a double-blind single night cross-over study. The results were favourable for triazolam in all the sleep parameters assessed. The significance of an hypnotic with a short life and its use in clinical practice is discussed.

Comparative study of the clinical effects of tofizopam, nitrazepam and placebo as oral premedication

In a double-blind randomized study 47 patients received tofizopam 100 mg orally the night before operation, and 100 mg on the morning of operation; 49 patients received nitrazepam 5 mg and 50 patients received placebo. On average the nitrazepam group slept better and were better sedated than the tofizopam or placebo groups. Compared with placebo or nitrazepam, tofizopam decreased the excitement of the patients. The effect tofizopam on apprehension and excitement was significantly better than those of placebo or nitrazepam. Nitrazepam, but not tofizopam, significantly decreased the induction requirements of thiopentone.