A comparison of the soft gelatin capsule and the tablet form of temazepam

Association of benzodiazepine injection with the prescription of temazepam capsules

Temazepam capsules have become a popular choice for benzodiazepine injection by injecting drug users, and serious vascular and tissue damage leading to ulcers and gangrene can result. We compared the self-reported benzodiazepine injecting behaviour of 91 heroin users with their Pharmaceutical Benefits Schedule (PBS) records for the preceding 5 years. We found that individuals prescribed PBS temazepam capsules were more likely to report injecting benzodiazepines than individuals who had either not been prescribed PBS temazepam capsules or had been prescribed PBS temazepam tablets. These results provide empirical support for the argument to limit the prescription and supply of temazepam capsules in Australia.

Modulation of rate of onset and intensity of drug effects reduces abuse potential in healthy males

Low, medium, and high doses of flunitrazepam were tested in three independent randomized, double-blind, balanced cross-over, placebo-controlled trials to study the influence of rate of onset of effects and dose administered on its acute effects. Three groups of 12 healthy male volunteers received six oral doses of placebo or flunitrazepam in slow and fast onset conditions as follows: six capsules of 0.16 mg (slow) and a single capsule of 0.8 mg (fast) in the low dose trial; six 0.25 mg (slow) and a single 1.25 mg (fast) capsules for medium dose; and six 0.4 mg (slow) and a single 2 mg (fast) capsule for high dose. At each dose level, slow or fast increasing flunitrazepam plasma concentrations lead to similar peak levels, but induced differential subjective and behavioral effects. In addition to objective and subjective sedation, flunitrazepam induced some pleasurable feelings, which were more intense in the fast than in the slow conditions. At the highest dose, unpleasant sedative effects surmounted positive effects, while at the lowest dose pleasurable effects were of low intensity. At the medium dose, the balance between pleasurable and unpleasant feelings resulted in euphorigenic effects, which were evident in the fast condition but were blunted in the slow condition.

Benzodiazepine pharmacodynamics: utility of eye movement measures

The utility of several measures of saccadic and smooth pursuit eye movements as benzodiazepine pharmacodynamic measures was explored in 24 psychiatrically and medically health control subjects. Measures of sedation and memory impairment were also included. Subjects received four logarithmically increasing doses of intravenous diazepam at 15-min intervals on 1 day resulting in monotonically increasing plasma diazepam levels, and placebo on another day in random order 1 week apart. Measures were collected twice at baseline, once after each dose of diazepam/placebo and twice more, 15 and 30 min after the last dose. Peak saccadic velocity and smooth pursuit gain showed the greatest overall and dose-dependent drug effect among eye movement measures. Although effect sizes at the highest dose for memory impairment and self-rated sedation were comparable to these two measures, reliability (i.e., placebo-day fluctuation) with these measures was considerably poorer. Log-linear pharmacodynamic modeling was used to calculate the effective dose (ED30) or concentration (EC30) required to reduce saccadic velocity or pursuit gain by 30%. Almost all (23/24) subjects had linear and easily interpretable plots for saccadic velocity, while a majority (19/24) of subjects had interpretable plots for smooth pursuit gain. The distribution of ED30 and EC30 values showed a wide range of sensitivities to diazepam. These findings suggest that saccadic velocity and smooth pursuit gain are sensitive, reliable, quantitative benzodiazepine pharmacodynamic measures.

Subjective and behavioral effects of diazepam depend on its rate of onset

This study addressed the assumption that rate of onset affects the euphorigenic effects of drugs. Drugs with rapid onset are commonly thought to be more euphorigenic than drugs with slower onset, but this idea has rarely been studied directly. Nine healthy male social drinkers, with no history of drug- or alcohol-related problems, participated in three sessions. On each session they received oral doses of placebo (PLAC), diazepam in a rapid onset condition (FAST), or diazepam in a slow onset condition (SLOW). In the FAST condition, they received a single 20 mg dose, whereas in the SLOW condition they received six 4 mg doses administered at 30-min intervals. Plasma levels of diazepam and desmethyldiazepam, subjective effects (including measures of euphoria), psychomotor performance and vital signs were monitored throughout each session. Although the FAST and SLOW conditions led to similar peak plasma levels of drug, the peak was attained earlier in the FAST condition (61 min versus 220 min). Subjects' scores on a measure of euphoria (MBG scale of the ARCI) were significantly higher in the FAST condition compared to the SLOW and PLAC conditions. Subjects exhibited significantly more behavioral signs of intoxication and greater psychomotor impairment in the FAST condition. Sedative effects of the drug were similar in magnitude, but the effects lasted slightly longer in the FAST condition. On several measures diazepam produced similar effects in the two conditions (e.g., ratings of strength of drug effect). These data provide limited support for the notion that a faster rate of onset of drug effects is associated with greater euphoria.

Rate of increase of plasma drug level influences subjective response in humans

This study addressed the commonly held, but seldom tested, notion that faster rates of increase of drug effects are associated with more positive subjective effects. Sodium pentobarbital was administered to normal healthy volunteers in either a single oral dose or in a series of divided, cumulating doses, and subjective responses were monitored. Twelve subjects participated in three weekly sessions, during which they received capsules containing placebo, 150 mg pentobarbital in a single dose (SIN) or 180 mg pentobarbital administered in six divided doses (DIV) of 30 mg every 30 min. Doses of pentobarbital in the SIN and DIV were selected to produce similar peak plasma levels. Blood samples were obtained at regular intervals for plasma drug level determinations, and throughout the session subjects completed self-report mood questionnaires (e.g., Profile of Mood States, visual analog ratings of drug liking and drug "high") and psychomotor performance tests (e.g., Digit Symbol Substitution Test). As expected, the SIN and DIV conditions yielded similar peak levels of pentobarbital, but the peak was attained more rapidly in the SIN condition. Despite the similarity in peak plasma levels, subjects reached greater peaks in ratings of "high" and wanted more of the drug when they were in the SIN condition. On an end-of-session liking questionnaire they also reported significantly greater liking of the drug in the SIN condition. On other measures of drug effects (e.g., sedation and psychomotor impairment) no significant differences were observed between the conditions. Thus, the rate of increase of the drug's effects specifically influenced subjects' ratings on subjective measures (e.g., "high" and liking) that may be associated with risk for abuse.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of temazepam on blood pressure regulation in healthy elderly subjects

1. Blood pressure regulation was studied in 12 healthy elderly subjects after double-blind randomised administration of placebo, 15 mg and 30 mg temazepam at 10.00 h and 22.00 h. 2. Supine and standing heart rate and blood pressure were measured after daytime administration and supine measurements were obtained during sleep. 3. Temazepam caused a fall in systolic blood pressure and an increase in heart rate after morning administration. These changes were greater in the standing position and were dose-dependent; for standing blood pressure and heart rate 1 h after administration there was a 7 mm Hg fall and 6 beats min-1 increase after 15 mg temazepam and a 10 mm Hg fall and 8 beats min-1 increase after 30 mg temazepam. Temazepam magnified the fall in systolic blood pressure and increase in heart rate that occurred with standing. Temazepam enhanced the fall in systolic blood pressure that occurred during sleep (mean +/- s.d.; placebo: -23 +/- 10 mm Hg, 15 mg temazepam: -31 +/- 13 mm Hg, 30 mg temazepam: -36 +/- 14 mm Hg). 4. These changes in blood pressure regulation caused by temazepam may have clinical importance in some elderly individuals.

A comparison of two sedative premedications for minor oral surgery under local anaesthesia

Two commonly used drug combinations were studied as premedications before surgical 3rd molar removal under local anaesthesia. The study was randomized, crossover and double-blind in 12 patients. Our routine premedication for lengthy operations, consisting of diazepam 10 mg p.o. plus i.m. scopolamine 0.006 mg/kg and morphine 0.2 mg/kg, was compared with a combination of diazepam 10 mg p.o. plus metoprolol 50 mg p.o. The latter combination was expected to cause fewer central nervous system side effects and be more suitable for out-patient surgery. Drug levels in blood, physiological and biochemical indicators of operation-related stress, CNS side effects, and the patients' subjective preferences were monitored. Both combinations were equally accepted by the patients, but the diazepam/scopolamine/morphine combination caused clearly more side effects after discharge than diazepam/metoprolol. The operation-related haemodynamic changes and plasma catecholamine responses were similar after both premedications.

Temazepam or midazolam for night sedation. A double-blind study

The effects of oral temazepam (20 mg), oral midazolam (15 mg) and a placebo were compared for night sedation on the evening prior to surgery in a double-blind study. Patients in the placebo group had significantly worse sleep than those in the temazepam (p = 0.004) or midazolam groups (p = 0.04). There was no significant difference between the two drug groups, nor between the residual effects of the three treatments. Temazepam appears to be somewhat more effective than the ultrashort-acting midazolam in pre-operative transient insomnia.

A methodological comparison of two formulations of temazepam in pharmacokinetic and pharmacodynamic aspects

In a double-blind and cross-over study 12 healthy subjects took temazepam 20 mg in two different formulations (soft gelatine capsule or uncoated tablet) and matched placebo at one-week intervals. Plasma temazepam concentrations at 0.5, 1, 2, 3, 8, 12 and 24 hours after treatment were analyzed by gas chromatography. Psychomotor performance was measured objectively (digit symbol substitution, letter cancellation, Maddox wing test) and subjectively (visual analogue scales) before the drug intake and 1, 2 and 3 hours later and the plasma benzodiazepine concentrations were analyzed also by radioreceptor bioassay. The two different formulations were compared in pharmacokinetic and pharmacodynamic terms, and the gas chromatographic and radioreceptor assays were compared. The soft gelatine capsule produced higher peak plasma concentrations than the uncoated tablet. The computed AUCs and elimination half-lives proved to be similar after either formulation. A satisfactory correlation between the bioassayed benzodiazepine concentrations and chemically assayed temazepam was shown. In pharmacodynamic terms the results suggest a shorter and somewhat smaller subjective response for the capsule than for the tablet form.

The use of oral benzodiazepines as premedications: the usefulness of temazepam

The primary aim of premedication is to relieve the patient's anxiety/restlessness before anaesthesia and to ensure optimum quantity and quality of sleep on the night preceding surgery. With these objectives in mind, oral benzodiazepines offer a good alternative to traditional parenteral premedicants, especially as the clear anxiolytic and sedative effects of the former are of great clinical value. Oral temazepam has proven to be a valuable premedicant given on the evening before operation and/or the following morning, before surgery. Administered as a sedative in a single 20 mg oral dose the night before surgery, temazepam provided a good night's sleep in 77 percent of gynaecological surgical patients; patients slept for 7.6 hours and had no significant residual effects. As a premedicant, temazepam was as effective as parenteral diazepam or papaveretum. Temazepam's short duration of action facilitates rapid postoperative recovery in children, adults, and in the elderly. Thus, it is indicated especially for short operative procedures when rapid recovery and swift return to fitness are essential.

Oral temazepam as a premedicant in elderly general surgical patients

In elderly, general surgical patients, oral temazepam 20 mg given in a soft gelatin capsule proved to be a useful light premedicant when given before spinal anaesthesia. In comparison with placebo, it caused preoperative subjective sedation, prevented an increase in heart rate and decreased serum cortisol, but not serum antidiuretic hormone levels. However, simple devices (linear analogue scale, Maddox wing test, critical flicker fusion apparatus) appeared to be quite ineffective in differentiating the clinical effects of temazepam from those of placebo. Temazepam given in a soft gelatin capsule to patients in the supine position had a reasonably fast gastrointestinal absorption, but its blood-lumbar cerebrospinal fluid penetration rate appeared to be quite slow.

Saccadic eye movements in determination of the residual effects of flunitrazepam

Saccadic eye movements and the subjective assessments of the volunteers were used in the determination of the residual effects of a single evening dose of flunitrazepam 0.5 mg, 1 mg and 2 mg or placebo. Sleep inducing and maintaining effects were subjectively assessed, too. Flunitrazepam at all three dose levels possessed sleep inducing and increasing effects (n = 9), but in the number of nocturnal awakenings and sedation in the morning (10 hrs after drug intake), no significant differences between placebo and the active medications were reported. However, saccadic eye movement recording could differentiate the residual effects produced by placebo or the active medication. No correlation was detected between the serum levels (radioreceptor assay) and saccadic eye movement recordings.