The effect of melperon on ocular readaptation time, as assessed by a new recording technique

A new simplified technique recording readaptation time after photo stress, RAT, is described. The psychometric properties in terms of internal consistency and retest reliability were tested, and the effect on RAT after intake of melperon at two different dose levels was investigated and correlated to blood plasma levels. The results show that there was a satisfactory consistency of RAT at each occasion but stability over a 1 month period could not be demonstrated. Significantly dose-dependent changes were recorded after intake of melperon but the prolongation of RAT was not significantly correlated to blood plasma levels.

Oxazepam esters. 1. Correlation between hydrolysis rates and brain appearance of oxazepam

Esters of the centrally acting oxazepam were investigated to find quantitative correlations between the pharmacokinetics of the parent drug and in vitro biotransformation rates and physicochemical properties of its prodrugs. The 14C-labeled aliphatic and omega-phenyl-substituted esters were administered intravenously to mice. Brain levels of the esters and oxazepam were determined and the latter was fitted to a simplified exponential equation. In vitro hydrolysis rate of the esters catalyzed by the hepatic microsomal fraction was measured with a pH stat. Pharmacokinetic constants characterizing the rising part of oxazepam brain levels correlate well with the chromatographic RM values and with in vitro maximal hydrolysis rates of the esters. The hydrolysis is capacity limited in the liver. In a closely related set of aliphatic esters, oxazepam brain penetration also correlates with the steric constant (ES) of its esters.

The effect of oxazepam on ocular readaptation time

The readaptation time (RAT) is the interval during which a person exposed to a bright intense light flash cannot perceive a given target. In this study the target used was an optokinetic pattern and the elicited nystagmus (OKN) was registered with electrooculography (EOG), thus giving an objective registration of RAT. Oxazepam in therapeutic doses was given to five healthy subjects and the RAT and serum concentrations of the drug were registered simultaneously at different time intervals. An almost parallel increase of RAT and serum concentration of oxazepam was recorded. This suggests that RAT reflects the depressant effect on the CNS of this drug and it may be used as an objective method of following the clinical effect of a depressant drug as a function of time after intake.

Effects on learning and memory of 2-week treatments with chlordiazepoxide lactam, N-desmethyldiazepam, oxazepam and methyloxazepam, alone or in combination with alcohol

A double-blind study with 40 healthy students was done in order to measure the effects of a 2-week treatment with chloridiazepoxide lactam (5 mg), nordiazepam (10 mg), oxazepam (15 mg) and methyloxazepam (20 mg) on immediate memory and associative learning. The drugs were administered t.i.d. and the tests were done after the very last capsule was given. It was ingested with a placebo drink and 0.5 g alcohol/kg body weight. Oxazepam and methyloxazepam alone behaved similar to the placebo. Immediate memory was significantly impaired following the treatment with nordiazepam, chlordiazepoxide lactam, alcohol, and after the simultaneous administration of nordiazepam and chlordiazepoxide lactam with alcohol. Chlordiazepoxide lactam was the only drug which alone impaired associative learning. Also alcohol alone, and all the drugs in combination with alcohol retarded learning acquisition.

Diazepam and its hydroxylated metabolites: studies on sleep in healthy man

1 The effects of diazepam 5, 10 and 15 mg and its hydroxylated metabolites, 3-hydroxydiazepam (temazepam) 10, 20 and 30 mg and 3-hydroxy, N-desmethyldiazepam (oxazepam) 15, 30 and 45 mg on sleep in healthy man were studied in young adulthood and in middle age. The effectiveness of the drugs for sleep during the day was also investigated.

2 In young adults diazepam and temazepam reduced sleep onset latencies and awake activity and increased total sleep time, and temazepam also reduced drowsy sleep. The activity of oxazepam was similar to that of temazepam except that it had no effect on sleep onset latencies. In middle age the effects of diazepam and temazepam were less pronounced than would be expected from studies in young adulthood. Essentially they reduced awake activity.

3 During the day diazepam increased total sleep time and reduced drowsy sleep in young adults, but temazepam and oxazepam had less activity than would be expected from their effect on night-time sleep. With temazepam there was no increase in total sleep time, although there was reduced awake activity and drowsy sleep, and with oxazepam total sleep time was increased without changes in awake activity and drowsy sleep.

4 It is considered that these hypnotics provide a basis for the management of sleep disturbance in persons involved in skilled activity. In limited doses each drug has hypnotic activity without residual effects on performance.

Performance studies with diazepam and its hydroxylated metabolites

1 Visuo-motor coordination has been used to study the immediate and residual effects of benzodiazepines on performance in man. The technique provides dose and time response data related to the decrement and the persistence of impaired performance. 2 With the overnight ingestion of flurazepam hydrochloride 30 mg and nitrazepam 10 mg, performance was impaired to 16 h and, at least, 19 h, respectively. Performance was not impaired after the overnight ingestion of diazepam, 5 and 10 mg, temazepam 10, 20 and 30 mg or oxazepam 15 and 30 mg. However, with temazepam 30 mg there was a trend toward impaired performance,, and with oxazepam 45 mg, performance was impaired 10 h after ingestion. With morning ingestion, coordination was impaired 0.5 and 2.5 h after diazepam 10 mg, at 0.5 h after temazepam 20 mg, and after oxazepam 30 mg at 2.5 and 4.5 hours. 3 The studies suggest that diazepam 5-10 mg, temazepam 10-20 mg and oxazepam 15-30 mg may be of use in the management of sleep disturbance when impaired performance the next day is to be avoided.

A comparative study on the clinical effects of oxazepam and diazepam: Relationship between plasma level and effect

The clinical effects of oxazepam and diazepam as oral premedicants were tested in a double-blind study of 60 children and 50 adults. The gas chromatographically measured concentrations of the active unconjugated forms of oxazepam and diazepam in the plasma were correlated to their clinical effects, as assessed both subjectively and objectively (sleep, sedation, apprehension, excitement, dizziness, emetic effect, headache, increase or decrease in systolic blood pressure, increase in pulse rate, venepuncture). No significant difference in the effects of these two benzodiazepine derivatives were observed, nor was there any obvious relationship between the plasma concentration and clinical effect.

Immediate and residual effects in man of the metabolites of diazepam

1 Immediate and residual effects of diazepam and its metabolites on visuomotor co-ordination have been studied in man. Performance was observed from 10.0-16.0 h after overnight ingestion of diazepam (5 and 10 mg), temazepam (10, 20 and 30 mg), oxazepam (15, 30 and 45 mg) and nordiazepam (5 and 10 mg), and from 0.5-6.5 h after morning ingestion of diazepam (10 mg), temazepam (20 mg), oxazepam (30 mg), and nordiazepam (5 and 10 mg). Immediate and residual effects of diazepam and temazepam were also studied on a choice response time test.

2 Visuo-motor co-ordination was not impaired after the overnight ingestion of 5 and 10 mg diazepam, 10, 20 and 30 mg temazepam, 15 and 30 mg oxazepam and 5 and 10 mg nordiazepam, though there was a trend of impaired performance over the dose range used with temazepam 10.0 h after ingestion. With 45 mg oxazepam performance at 10.0 h was impaired compared with performance at 14.0 (P < 0.01) and 16.0 h (P < 0.001). Performance on the choice response time test was not impaired after the overnight ingestion of 5 and 10 mg diazepam and 10, 20 and 30 mg temazepam.

3 With morning ingestion visuo-motor co-ordination was impaired at 0.5 (P < 0.01) and 2.5 h (P < 0.05) after 10 mg diazepam, at 0.5 (P < 0.001) after 20 mg temazepam, and at 2.5 (P < 0.01) and 4.5 h (P < 0.05) after 30 mg oxazepam. Performance 6.5 h after 10 mg nordiazepam was impaired compared with performance 0.5 and 2.5 h (P < 0.01) after ingestion. Performance on the choice response time test was impaired 1.0 h after ingestion of 10 mg diazepam (P < 0.01) and 20 mg temazepam (P < 0.05).

4 It is considered that diazepam (5-10 mg), temazepam (10-20 mg) and oxazepam (15-30 mg) would be useful hypnotics within the dose ranges indicated, at least for occasional use, when impaired performance the next day would be unacceptable. The studies with nordiazepam suggest that, though this drug may have limited effects on performance, it may have persistent effects on behaviour consistent with its clinical use as an anxiolytic.

Biochemical and pharmacological properties of oxazepam

Oxazepam is the final metabolic product in vitro and in vivo of a large number of pharmacologically active benzodiazepines. Oxazepam shows antimetrazol activity varying in intensity and duration according to the animal species considered. This difference is in part related to different "sensitivity" and in part due to different disposition of oxazepam. Particularly relevant is the difference in biliary excretion by various animal species. Oxazepam is currently available as a racemate but two optical isomers can be separated as succinate half esters. The (+) form appears to be more active than the (-) form, probably because more oxazepam is released from the (+) than the (-) isomer in vivo. In vitro studies confirm that the liver hydrolyzes the (+) oxazepam succinate half ester more than the (-) form. Other work has aimed at analyzing the effects of oxazepam on brain chemical mediators, with particular reference to the cholinergic system. Finally it is shown that oxazepam, similarly to other benzodiazepines, increased aggressiveness in male mice during chronic treatment.

The effect of oxazepam on sleep in normal human volunteers

The effects of 25 mg of oxazepam, a benzodiazepine with a short half-life and no active metabolites, were compared with placebo in two healthy volunteers in a single-blind polygraphically recorded sleep study. The experiment lasted for 24 nights and recordings were made for 11 nights. It was found that 25 mg oxazepam induced sleep faster than placebo, and that the subjects awoke less often during the treatment period. The total amount of REM-sleep was not affected. However, REM-sleep was shortened during the first part of the night and extended during the latter part of the night. Slow-wave sleep diminished differently in the two subjects, possibly due to interindividual differences in the rate of elimination of oxazepam. The effect on blood pressure was small, and the normal physiological difference between bedtime and morning blood pressure was preserved.

Comparison of oxazepam, flurazepam and chloral hydrate as hypnotic sedatives in geriatric patients

In a four-week study, a comparison was made of oxazepam, flurazepam and chloral hydrate as hypnotic sedatives in 17 geriatric patients. Each drug was given alone for six nights, with a two-night placebo interval following each phase. Each patient completed an additional placebo phase (up to six nights) before each drug phase. The number of awakenings per night and the sleep latency (time required to fall asleep) were determined from the patients' reports and from the reports of a nurse-observer. Only for oxazepam was the number of patient-reported awakenings per night significantly less than for placebo, although with both oxazepam and flurazepam the awakenings were fewer than with chloral hydrate. According to the patient-reports, sleep latency was significantly lower with flurazepam than with placebo; for oxazepam and chloral hydrate the latencies were not significantly different from those for flurazepam or placebo. Only for oxazepam were the patients' ratings of sleep quality significantly greater than for placebo. The objective assessment of sleep by the nurse-observer usually confirmed the patients' assessments. Morning drowsiness was the most common side effect, reported equally for placebo and for the active drugs. Drowsiness during the day was reported less frequently for oxazepam than for flurazepam, chloral hydrate or placebo. It is concluded that oxazepam is safe and efficacious for the short-term management of insomnia in the elderly.

[Modulation of autonomic correlates of emotional stress and adaptive responses]

The character and dynamics of the cardio-vascular response to psychogenic stress (confrontation of cat and dog) depends on active or passive type of behavioral response. Tranquilizers inhibit long-lasting hypertension otherwise occurring after the stress stimulus. Adaptive cardio-vascular responses and baroreceptor reflexes did not alter after tranquilizers administration. Effects of psychotropic drugs correspond to the type of individual behavioral response.

[Does oxazepam (ADUMBRAN) interfere with anticoagulant treatment. A controlled study. (author's transl)]

Newer communications dealing with drug interaction between tranquillizers and anticoagulants and the frequent combined intake of these drugs have induced us to perform a series of coagulation-and platelet parameters in 21 antiocoagulated patients with and without oxazepam (Adumbran). Control of adherence to the prescriptions was stressed upon: all cases were controlled by analysis of urin and nonadherent patients were excluded from statistical evaluation of hemostatic parameters. In the obtained well defined group no differences were observed in the effect of constant doses of anticoagulants and different tests of plasmatic coagulation and platelet aggregability.

Effects of chlordiazepoxide, oxazepam, chlorpromazine, and d-amphetamine on sexual responses in male and female hamsters

The acute effects on sexual behavior of oxazepam (16--64 mg/kg), chlordiazepoxide (8--64 mg/kg), chlorpromazine (2--8 mg/kg), and d-amphetamine (0.8--3.2 mg/kg) were examined in intact male and female golden hamsters (Mesocricetus auratus). Intraperitoneal injections were given 45 min before the first behavioral test. In 10-min tests, lordosis was observed in estrous females both before and after copulation, and mounts, intromissions, and ejaculations were observed in males. Dose-response related decrements in male sexual behavior were observed following chlorpromazine and chlordiazepoxide. All dose levels of oxazepam depressed male sexual behavior. The highest dose of chlordiazepoxide and oxazepam attenuated the onset of female sexual behavior, and all dose levels reduced postcopulatory lordosis durations. Amphetamine did not interrupt either male or female sexual behavior, and chlorpromazine disrupted male but not female behavior.

Effects of chlordiazepoxide and oxazepam administration on verbal hostility

We compare the effects of chlordiazepoxide, oxazepam, and placebo on hostility, as both an inner motivational or potential state and verbal interpersonal behavior. This article reports the findings relevant to the latter dimension of hostility and integrates them with those findings, presented in an initial report, relevant to hostility as an inner motivational state. The verbal data again support the hypothesis that chlordiazepoxide-induced increases in verbal interpersonal hostility, following frustration, are greater than those associated with placebo. With regard to oxazepam, the verbal hostility data were consonant with the motivational data that suggested that oxazepam does not substantially disinhibit hostility but did not as consistently differentiate oxazepam and chlordiazepoxide at the level of overt hostile behavior.

Selection among benzodiazepines for alcohol withdrawal

Four pharmacologic differences among the benzodiazepines, which are the drugs of choice to conduct alcohol withdrawal, guide selection of the appropriate one: chlordiazepoxide, diazepam, oxazepam, or chlorazepate. Bases for selection include: (1) availability of other than oral dosage forms; (2) differences in additive effect with alcohol in producing central nervous system depression; (3) differences in anticonvulsant effect; and (4) differences in duration of effect in the body (ie, half-life). Decreasing dosage schedules are preferred to a steady dosage. Illustrative dosage schedules for using chlordiazepoxide and diazepam to conduct alcohol withdrawal are given.

Benzodiazepines: behavioral and neurochemical mechanisms

The therapeutic effects of benzodiazepines in psychoneurosis may depend in part on their ability to release or disinhibit a patient's anxiety-suppressed gratification-seeking behavior. Benzodiazepines may disinhibit behavior by reducing the activity of serotonin (and possibly acetylcholine) neurons in the brain's "punishment" system. Reduction of serotonin transmission may be due to a facilitation of gamma-aminobutyric acid (GABA)-mediated presynaptic inhibition at the serotonin nerve terminal.

[Psychopharmacologic studies on the combined effect of alcohol and oxazepam on reactivity pattern. II. Subjective feeling and reaction behavior]

Psychopharmacological investigations of the subjective state of being and the reactivity pattern of a group of 14 probands show a good agreement with the alterations of performance reported in the first part of this publication and with the data on polarity profiles. In addition to a sedative effect the interaction of alcohol and oxazepam in the oxazepam trial results in dysphoric changes of mood and related significant alterations of polarity profiles. A correlation of the changes of performance and the alterations of the polarity profiles with the respective blood levels of alcohol and oxazepam could be demonstrated.

Multiple oral doses of diazepam, oxazepam and phenobarbital to dogs--behavioural effects and correlation with antipyrine half-life

The effects of prolonged treatment with phenobarbital, diazepam, and oxazepam on behaviour and on the plasma half-life of antipyrine have been studied in the dog. In this species the biotransformation of diazepam and oxazepam is known to be very similar to man. After equipotent doses of phenobarbital (25 mg/kg) and diazepam (35 mg/kg), antipyrine half-life was found to decrease 80 and 40%, respectively, while after treatment with oxazepam (150 mg/kg) there was an increase of 20%. The behavioural effects declined in the dogs during the course of treatment with diazepam but were rather constant during treatment with oxazepam.

Interactions between narcotic analgesics and benzodiazepine derivatives on behavior in the mouse

Interactions between the benzodiazepine derivatives, diazepam and oxazepam, and the narcotic analgesics, morphine and methadone, were evaluated on locomotor activity and in the tail-flick and hot-plate tests for analgesia in the mouse. The dose-related stimulation of locomotor activity by morphine was reduced by diazepam and oxazepam at doses which alone had no effect on locomotor activity. However, only oxazepam reduced the dose-related stimulation of locomotor activity by methadone. The observed decreases produced by diazepam and oxazepam were comparable in magnitude to those produced by naloxone. Stimulation of locomotor activity by d-amphetamine was not affected by either diazepam or oxazepam. Dose-response curves for locomotor activity were also determined with morphine and methadone administered intraventricularly. As before, diazepam and naloxone given i.p. decreased the stimulation of locomotor activity produced by morphine, but only naloxone affected methadone-stimulated locomotor activity. Neither diazepam, oxazepam nor naloxone reduced the brain or plasma levels of 3H-morphine or 3H-methadone. In contrast to the results on locomotor activity, neither of these benzodiazepines significantly modified the dose-response curves of morphine or methadone in either test for analgesia. The mechanisms involved in the observed interactions on locomotor activity may be related to the influences of benzodiazepines and narcotic analgesics on motor efferent pathways summating in such a manner as to interfere with the ability of the mice to locomote. The present results demonstrate that prominent interactions occur between members of the benzodiazepine and narcotic analgesic classes; these interactions are dependent upon both the specific combination of drugs administered and upon the test procedure.

Increased aggression in rats after withdrawal of long term used oxazepam

The withdrawal of oxazepam (5 mg/kg i.p.) applied for 1 year in rats, increased shock-induced aggression of animals. This phenomenon is interpreted as a sign of abstinence and suggests that long-term treatment causes dependence to oxazepam in rats.

Blockade of the specific lethal effects of narcotic analgesics in the mouse

The capacity of the narcotic antagonists naloxone and nalorphine and the benzodiazepine derivatives diazepam and oxazepam to increase the LD50s of the narcotic analgesics morphine and methadone administered at convulsant doses was eveluated in the mouse. Naloxone produced a dose-related increase in the LD50s of both morphine and methadone. Iiazepam and oxazepam were also effective in increasing the LD50s of the narcotics; this effect was additive with that of naloxone. However, the maximal increase in the LD50s of the narcotics produced by pretreatment with naloxone alone was not increased further by the combined pretreatment of naloxone and a benzodiazepine. The anticonvulsant trimethadione did not elevate the LD50s of methadone, nor did it potentiate the effects of naloxone. These results suggest that the benzodiazepines may reduce the lethality of narcotic analgesics administered at high doses by a mechanism other than by an anticonvulsant effect alone. Therefore, the present results support the conclusion that the capacity to increase the convulsant LD50 of the narcotic analgesics is a general property of the narcotic antagonists.

[Psychopharmacological studies on the interactions between alcohol and oxazepam with regard to reaction behavior. 1st communication. Changes of psychomotor coordination and reaction behavior]

The interactions between oxazepam and ethanol were investigated in a pharmacopsychological study. The results of the psycho-experimental investigations are reported in this paper. The effects of oxazepam and/or ethanol doses given to 14 subjects with known blood concentrations of the respective substances were monitored and compared to placebo effects. - An analysis of the experiments with respect to the psychomotoric responses showed a tendency towards motoric instability under ethanol (A), whereas in the placebo experiment a relatively constant level of efficiency was maintained. In the oxazepam experiment (C) a slowing of the psychomotoric functions was observed. The concomitant influence of ethanol and oxazepam accentuates the motoric instability with a delay of the motoric responses. These effects remain visible, though slightly modified, after the administration of both substances at intervals (E). The experiments showed a decrease in efficiency during continuous exercise, a delayed response to optic and acoustic stimuli, and a retardation of the entire behavioral pattern under the influence of ethanol and oxazepam. The results indicate the existence of marked interactions between ethanol and oxazepam.

[Comparative study on the effect of anticholinergic substances on basic gastric secretion as well as on gastric secretion stimulated by pentagastrin or hypoglycemia (author's transl)]

The effect of orally administered ipratropiumbromide and propanthelinbromide on the basic gastric secretion as well as on the gastric secretion stimulated by pentagastrin or hypoglycemia due to application of insulin was tested intraindividually in a double blind comparative study. Drug dosage and time after the drug effect was measured varied. In addition the anticholinergic effect of ipratropiumbromide on the basic as well as on the gastric secretion stimulated by pentagastrin was compared to that of oxacepam. The inhibitory effect of ipratropiumbromide on the basic gastric secretion as well as on the secretion stimulated by pentagastrin and hypoglycemia is more pronounced than that of propanthelinbromid. The effect on the basic secretion reached its peak 450 min after drug application whereas the maximal effect on pentagastrin stimulated secretion showed earlier. The effect described was only seen with a dose of the anticholinergic drug of at least 30 mg. A combination of ipratropiumbromide+oxacepam has no effect stronger than ipratropiumbromide alone. On the contrary, it rather seems to have an augementative effect on pentagastrin stimulated gastric secretion that may be compensated completely by ipratropiumbromide. On the basic of these results a direct influence of anticholinergic substances on the parietal cell is discussed.

[Comparison of the effects of di-n-propylacetate and oxazepam on spontaneous and conditioned responses in mice]

When effects of di-n-propylacetate (nDPA) on various patterns of behaviour in mice in "novel environment" tests are compared with the effects of oxazepam, it appears that the stimulating action of nDPA is more evident than its antianxiety effects. Learning seems to be facilitated by this stimulating action.

[Studies on the action of an anticholinergic agent in combination with a tranquilizer on gastric juice secretion in man]

A double-blind study with intra-individual comparisons was carried out to investigate the effects of 15 mg of (8r)-3alpha-hydroxy-8-isopropyl-1alphaH-tropanium bromide(+/-)-tropate (Sch 1000), 15 mg Sch 1000 + 10 mg oxazepam, 10 mg oxazepam and placebo with oral administration in randomized sequence on gastric juice volume, amount of acid, concentration and pH values in 12 healthy volunteers. The secretion parameters were measured during a 1-h basal period and a 2-h stimulation period. The gastric juice was obtained in 15 min portions via stomach tube. Stimulation was effected by 1 mug/kg/h pentagastrin via drip infusion. The Friedman test was used for the comparative statistical evaluation, and individual comparisons were carried out by means of the Wilcoxon test (pair-differences rank). The results show that Sch 1000 and Sch 1000 + oxazepam were equal in effect on basal and stimulated secretion volume. As compared with placebo, it was not possible to establish an effect on secretion volume for oxazepam alone. Sch 1000 and Sch 1000 + oxazepam were found to be equipotent in reducing the amount of basal acid, while oxazepam reduced this quantity only during the first 30 min of basal secretion. None of the three active preparations was capable of inhibiting the stimulated acid, although both Sch 1000 preparations produced a clear trend towards lowered mean values. During the basal secretion period, all three test preparations had an inhibiting action on acid concentration, but none of them had a significant effect during the stimulation period. The pH value was savely increased only by Sch 1000 and Sch 1000 + oxazepam, and this even only during the basal period. The results are discussed.

[Studies on the action of an anticholinergic agent in combination with a tranquilizer on gastric juice secretion in man]

A double-blind study with intra-individual comparisons was carried out to investigate the effects of 15 mg of (8r)-3alpha-hydroxy-8-isopropyl-1alphaH-tropanium bromide(+/-)-tropate (Sch 1000), 15 mg Sch 1000 + 10 mg oxazepam, 10 mg oxazepam and placebo with oral administration in randomized sequence on gastric juice volume, amount of acid, concentration and pH values in 12 healthy volunteers. The secretion parameters were measured during a 1-h basal period and a 2-h stimulation period. The gastric juice was obtained in 15 min portions via stomach tube. Stimulation was effected by 1 mug/kg/h pentagastrin via drip infusion. The Friedman test was used for the comparative statistical evaluation, and individual comparisons were carried out by means of the Wilcoxon test (pair-differences rank). The results show that Sch 1000 and Sch 1000 + oxazepam were equal in effect on basal and stimulated secretion volume. As compared with placebo, it was not possible to establish an effect on secretion volume for oxazepam alone. Sch 1000 and Sch 1000 + oxazepam were found to be equipotent in reducing the amount of basal acid, while oxazepam reduced this quantity only during the first 30 min of basal secretion. None of the three active preparations was capable of inhibiting the stimulated acid, although both Sch 1000 preparations produced a clear trend towards lowered mean values. During the basal secretion period, all three test preparations had an inhibiting action on acid concentration, but none of them had a significant effect during the stimulation period. The pH value was savely increased only by Sch 1000 and Sch 1000 + oxazepam, and this even only during the basal period. The results are discussed.

[Studies on the action of an anticholinergic agent in combination with a tranquilizer on gastric juice secretion in man]

A double-blind study with intra-individual comparisons was carried out to investigate the effects of 15 mg of (8r)-3alpha-hydroxy-8-isopropyl-1alphaH-tropanium bromide(+/-)-tropate (Sch 1000), 15 mg Sch 1000 + 10 mg oxazepam, 10 mg oxazepam and placebo with oral administration in randomized sequence on gastric juice volume, amount of acid, concentration and pH values in 12 healthy volunteers. The secretion parameters were measured during a 1-h basal period and a 2-h stimulation period. The gastric juice was obtained in 15 min portions via stomach tube. Stimulation was effected by 1 mug/kg/h pentagastrin via drip infusion. The Friedman test was used for the comparative statistical evaluation, and individual comparisons were carried out by means of the Wilcoxon test (pair-differences rank). The results show that Sch 1000 and Sch 1000 + oxazepam were equal in effect on basal and stimulated secretion volume. As compared with placebo, it was not possible to establish an effect on secretion volume for oxazepam alone. Sch 1000 and Sch 1000 + oxazepam were found to be equipotent in reducing the amount of basal acid, while oxazepam reduced this quantity only during the first 30 min of basal secretion. None of the three active preparations was capable of inhibiting the stimulated acid, although both Sch 1000 preparations produced a clear trend towards lowered mean values. During the basal secretion period, all three test preparations had an inhibiting action on acid concentration, but none of them had a significant effect during the stimulation period. The pH value was savely increased only by Sch 1000 and Sch 1000 + oxazepam, and this even only during the basal period. The results are discussed.

Stimulatory effects of chlordiazepoxide, diazepam and oxazepam on the drug-metabolizing enzymes in microsomes

5 days' exposure of rats to daily doses of 400 mg/kg body wt. of chlordiazepoxide, diazepam and oxazepam stimulated the microsomal metabolism in the liver, as evidenced by acceleration of both p-hydroxylation of aniline and hydroxylation of benzene. The effect was accompanied by an increased concentration of liver microsomal protein and by the development of tolerance to the drugs. Similar effects were found after exposure of rats to lower doses of the drugs. The metabolism of aniline in vivo in rats treated with chlordiazepoxide was accelerated; this was correlated with development of tolerance to these drugs. It is suggested that both the stimulation of microsomal metabolism and the development of tolerance are associated with the induction of microsomal drug-metabolizing enzymes.

The differential effects of chlordiazepoxide and oxazepam on hostility in a small group setting

The authors compared the effects of chlordiazepoxide, oxazepam, and placebo on hostility, as an inner motivational or arousal state, in moderately and highly anxious male research volunteers. The data again supported the hypothesis that clordiazepoxide-induced increases in motivational hostility are more frequent and intense than those associated with placebo and oxazepum. The data also suggest that oxazepam may be a more specific "hostility tranquilizer" than other benzodiazepines.

Toxicological and pharmacological investigations of pinazepam (7-chloro-1-propargyl-5-phenyl-3H-1,4-benzodiazepin-2-one): a new psychotherapeutic agent

The pharmacological and toxicological properties of 7-chloro-1-propargyl-5-phenyl-3H-1,4-benzodiazepin-2-one (pinazepam) were investigated and compared with those of diazepam. In mouse and rat acute toxicity, in rat motor coordination and in rat metrazol convulsion tests pinazepam was compared with oxazepam too. Pinazepam, which is characterized by the presence of a propargylic side chain, showed a lower toxicity, hypnotic activity and muscular-relaxant activity than diazepam. Pinazepam and diazepam showed, however, similar activity in reducing aggressive behaviour in mice, stimulating the exploratory behaviour in rats and in potentiating hexobarbital narcosis. No clear-cut differences were observed in the anticonvulsant properties of the two drugs when tested against metrazol, strychnine and electroshock induced seizures. Pinazepam differs from diazepam for its longer duration of action. The main metabolic product found in the urine of rats and dogs treated with pinazepam was oxazepam.

Minor tranquilizers in the treatment of aggression

Clinical trials designed to evaluate the efficacy of drugs in human aggression have been scarce until recent years. The potential antiaggressive action of minor tranquilizers in humans has received little attention in spite of the claimed "taming effect" in some animal studies. A recent report examining the literature regarding the effects of benzodiazepines on animal models of aggressive behavior has pointed out the lack of consistency in such findings. Similar observations have been noted in humans where reduction in aggressive manifestations is contrasted with an increase in hostility in a few studies, as well as with the appearance of "paradoxical" rage reactions. Some variables that could account for such discrepancies have been advanced. They include, among others, dosage, acute vs. chronic drug administration, and possible qualitive differences among this group of agents. Individual variations as to presenting clinical picture, initial levels of anxiety and hostility, and personality types have also been mentioned. Implications of some of these findings for future clinical research are discussed. At present, a study designed to test the efficacy of two benzodiazepines, at dosages higher than those usually recommended, is being carried out in a population of anxious, aggressive-prone individuals with poor impulse control. Thus far, and in agreement with our previous clinical experience, we have not seen "paradoxical" rage and such high dosages have been well tolerated.