Exposure via biotransformation: Oxazepam reaches predicted pharmacological effect levels in European perch after exposure to temazepam.

It is generally expected that biotransformation and excretion of pharmaceuticals occurs similarly in fish and mammals, despite significant physiological differences. Here, we exposed European perch (Perca fluviatilis) to the benzodiazepine drug temazepam at a nominal concentration of 2 µg L-1 for 10 days. We collected samples of blood plasma, muscle, and brain in a time-dependent manner to assess its bioconcentration, biotransformation, and elimination over another 10 days of depuration in clean water. We observed rapid pharmacokinetics of temazepam during both the exposure and depuration periods. The steady state was reached within 24 h of exposure in most individuals, as was complete elimination of temazepam from tissues during depuration. Further, the biologically active metabolite oxazepam was produced via fish biotransformation, and accumulated significantly throughout the exposure period. In contrast to human patients, where a negligible amount of oxazepam is created by temazepam biotransformation, we observed a continuous increase of oxazepam concentrations in all fish tissues throughout exposure. Indeed, oxazepam accumulated more than its parent compound, did not reach a steady state during the exposure period, and was not completely eliminated even after 10 days of depuration, highlighting the importance of considering environmental hazards posed by pharmaceutical metabolites.

Investigating tissue bioconcentration and the behavioural effects of two pharmaceutical pollutants on sea trout (Salmo trutta) in the laboratory and field.

Pharmaceuticals entering aquatic ecosystems via wastewater effluents are of increasing concern for wild animals. Because some pharmaceuticals are designed to modulate human behaviour, measuring the impacts of exposure to pharmaceuticals on fish behaviour has become a valuable endpoint. While laboratory studies have shown that pharmaceuticals can affect fish behaviour, there is a lack of understanding if behaviour is similarly affected in natural environments. Here, we exposed sea trout (Salmo trutta) smolts to two concentrations of two pharmaceutical pollutants often detected in surface waters: temazepam (a benzodiazepine, anxiolytic) or irbesartan (an angiotensin II receptor blocker, anti-hypertensive). We tested the hypothesis that changes to behavioural traits (anxiety and activity) measured in laboratory trials following exposure are predictive of behaviour in the natural environment (downstream migration). Measures of anxiety and activity in the laboratory assay did not vary with temazepam treatment, but temazepam-exposed fish began migrating faster in the field. Activity in the laboratory assay did predict overall migration speed in the field. In contrast to temazepam, we found that irbesartan exposure did not affect behaviour in the laboratory, field, or the relationship between the two endpoints. However, irbesartan was also not readily taken up into fish tissue (i.e. below detection levels in the muscle tissue), while temazepam bioconcentrated (bioconcentration factor 7.68) rapidly (t1/2 < 24 h). Our findings add to a growing literature showing that benzodiazepine pollutants can modulate fish behaviour and that laboratory assays may be less sensitive at detecting the effects of pollutants compared to measuring effects in natural settings. Therefore, we underscore the importance of measuring behavioural effects in the natural environment.

Sexual assault under benzodiazepine submission in a Paris suburb.

Sexual assaults under benzodiazepine submission have been described, since use of benzodiazepine enables non consensual sexual activity but rarely fully reported. An accurate evaluation of the phenomenon has seemed interesting. Files of 23 adult males and females examined at the Emergency Forensic Unit of an University Teaching Hospital near Paris were reviewed. All the victims had complained from sexual assault under drug submission, in the years 1996 and 1997. A complete examination for sexual assault was realised linked to clinical examination of drug intoxication. Every victim of rape under drug submission was sampled for urine screening (mean delay of 17.5 h after sexual assault) and blood alcohol level quantification. Urine was screened for benzodiazepines, cocaine, opiates and cannabinoids with qualitative immunochromatographic test. Traumatic lesions of sexual penetration were retrieved in 10 victims and sperm in 5. Clinical signs of benzodiazepine intoxication were retrieved in 12 out of 23 victims. Urine benzodiazepine screening was positive, over the cut-off values (300 ng/mL)when sampled less than 20 h after the facts. In 6 out of 23 victims, drugs of abuse and alcohol were associated to benzodiazepines. A reinforced attention can be brought to the rape under drug submission including the need of a proper examination and samplings shortly after the alleged facts to ascertain the diagnosis and to help the victim facing the Justice inquiry.

Subjective effects during administration and on discontinuation of zopiclone and temazepam in normal subjects.

The purpose of the study was to ascertain whether the new hypnotic, zopiclone, was likely to produce rebound problems after short-term use, in comparison with placebo and a standard hypnotic, temazepam, and whether tapering the dosage lessened any such effects. Ten normal v olunteer subjects were administered 5 treatment sequences, each lasting 4 weeks, using a balanced design, with at least 2 weeks between sequences. The treatment sequences were: (table: see text) Each drug was given at night before retiring to bed. Daily ratings comprised a Sleep Questionnaire, Mood Rating Scales, the Spielberger State Anxiety Inventory and Bodily Symptom Scales. Both drugs improved quality of sleep but their discontinuation was followed by some worsening which was postponed but not avoided by halving the dosage for a week. Speed of, and feeling on, awakening showed discontinuation effects with temazepam but not with zopiclone. Zopiclone was associated with feelings of being troubled, tense, antagonistic and bored whereas temazepam produced drowsiness, clumsiness, dreaminess and sadness. Some increase in these ratings was noted after stopping temazepam and these were less after having the dosage. Zopiclone was associated with minimal such effects. For bodily symptoms, zopiclone produced some headache, a metallic taste, and some blurring of vision; temazepam induced nausea, memory impairment and pins and needles. Withdrawal effects on bodily symptom ratings were inconsistent and not affected by tapering off the dose. In conclusion, the administration of zopiclone tends to be associated with some dysphoric effects, temazepam with sedation. Rebound effects are minimal with zopiclone and reducing the dosage gradually does not seem necessary.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic toxicity/carcinogenesis study of temazepam in mice and rats.

The benzodiazepine temazepam was given to Charles River CD rats for 2 years in the diet at dosages of 10, 40, and 160 mg/kg day. An 18-month study was performed in Charles River CD-1 mice via dietary admixture at dosages of 10, 80, and 160 mg/kg/day. Mean body weights were significantly decreased for high dose rats of both sexes from Treatment Week 39 until termination. All drug treated male groups had a higher rate of mortality when compared to the male control groups, primarily due to deaths occurring between 19 to 24 months. Compound-related hepatic lipidosis accompanied by an increase in liver weights was observed at the high dose level in the 6- and 12-month and terminal sacrifices, as well as the middle dose level at the 12-month interim sacrifice. No evidence was found of compound induced carcinogenicity at any time period. Mortality for male mice was significantly higher in the two higher dose groups; this resulted from bite wounds associated with a drug-related increase in fighting behavior. An isolated finding of borderline statistical significance (p = 0.0556) was noted for hepatocellular adenomas in high dose female mice (4/100) at the 18-month terminal sacrifice. This incidence is well within the reported historical control range (0-14%). Minimal hepatoproliferative (hyperplastic nodules) and vascular effects (telangiectasis) were seen in the high dose male and female mice at the 18-month terminal sacrifice. Thus, these results were similar to those previously reported for oxazepam although meaningful effects on neoplasia did not occur with temazepam. Unlike in man, temazepam is primarily metabolized to oxazepam in the mouse and thus these results are not adverse with regard to human safety evaluation.

Temazepam (Restoril, Sandoz Pharmaceuticals).

Temazepam is a benzodiazepine derivative indicated for the treatment of insomnia. Pharmacokinetic studies of the hard capsule formulation indicate that the mean time to peak is 2.99 hours and the mean elimination half-life is 14.7 hours. Sleep laboratory studies have demonstrated improvements in all sleep parameters except sleep onset latency. Clinically, patients report improvements in all sleep parameters including sleep onset latency. The efficacy of temazepam compares favorably with barbiturates, glutethimide, nitrazepam, lorazepam, oxazepam, and flurazepam. It has not been compared with diazepam in the clinical setting. Side effects include drowsiness, dizziness, and lethargy. The incidence of hangover effects from 15- and 30-mg doses is relatively low. Temazepam has no proven advantages over other benzodiazepine hypnotics. The major issues that need further clarification include temazepam's sleep induction properties and the relative incidence of hangover and rebound insomnia when compared with longer-acting benzodiazepines.