The effect of temazepam on melatonin secretion and light sensitivity

Later sleep schedule and depressive symptoms are associated with usage of multiple kinds of hypnotics

OBJECTIVE

Usage of high doses of hypnotics possibly causes various adverse events. However, the risk factors of using multiple kinds of hypnotics have been inconclusive. To clarify this, we conducted a web-based cross-sectional questionnaire survey on the Japanese adult population.

METHODS

A cross-sectional Internet-linked survey was conducted on 10,016 individuals and 1030 participants (10.3%) having subjective insomnia proceeded to subsequent analyses. The analyzed subjects were categorized into non-users of hypnotics (n = 833; 80.9%), users of a single kind of hypnotic (n = 96; 9.3%), and users of multiple kinds of hypnotics (n = 101; 9.8%). The descriptive variables including demographic data, scores of Center for Epidemiological Studies Depression Scale (CES-D), Short Form-8 Health-Related Quality of Life [QOL (SF-8)], Pittsburgh Sleep Quality Index (PSQI), and other parameters were compared among the groups.

RESULTS

The users of multiple kinds of hypnotics had the highest mean score of CES-D, the lowest mental component summary of QOL (SF-8), and the latest sleep schedule among the three groups (p < 0.001). Logistic regression analyses revealed that sex (female: OR = 2.38; p < 0.001) and age (≥43 years old: OR = 2.61; p < 0.001) were independently associated with use of a single kind of hypnotic, while later sleep schedule (midpoint of sleep ≥5:30 a.m.: OR = 2.26; p < 0.001) and higher CES-D score (≥16 points: OR = 2.41; p < 0.001) were independently associated with use of multiple kinds of hypnotics.

CONCLUSIONS

Characteristics of users of multiple kinds of hypnotics were different from those of users of a single kind of hypnotic.

Zaleplon increases nocturnal melatonin secretion in humans

Insomnia is the most common sleep condition. Many hypnotics decrease nocturnal melatonin secretion. The aim of this research consists of studying the effect of the hypnotic drug zaleplon on melatonin secretion. Twelve non-smoker drug-free healthy male subjects participated in the study. All participants were normal sleepers and aged 33.2 +/- 11.7 years. They orally took 10 mg of zaleplon at 22:00 h in a double-blind, randomized, cross-over design. The study was carried out during two consecutive days in a week-end. Blood samples were extracted at 22:00, 23:00, 24:00, 01:00, 02:00 and 12:00 h. Melatonin was measured by an ELISA assay. All the subjects had a circadian rhythm of melatonin secretion. Zaleplon compared to placebo increased significantly the melatonin levels at 23:00, 24:00 and 01:00 h. No differences in melatonin levels between placebo and zaleplon were found at 12:00, 22:00 and 02:00 h. Zaleplon compared to placebo increased by 46% the Area Under the Curve of melatonin secretion. The present study indicates that zaleplon increases nocturnal melatonin secretion without increasing daytime melatonin levels. We suggest that when clinicians prescribe a hypnotic, the effect on melatonin levels should be another parameter to be taken into account.

Urinary 6‐hydroxymelatonin sulfate excretion in intellectually disabled subjects with sleep disorders and multiple medications: Validation of measurements in urine extracted from diapers

The aim of this study was to examine the applicability of urinary 6-hydroxymelatonin sulfate (MT6s) measurements in the evaluation of melatonin secretion in intellectually disabled patients with sleep disorders. All 17 patients received drugs with potential interactions with melatonin metabolism. Serum melatonin 24-h profiles were determined at hourly intervals. The area under the curve (AUC) value, peak amplitude, half-rise time, and half-decline time were calculated individually. Urinary MT6s excretion was determined from samples collected from disposable diapers during three consecutive days at varying intervals. The average excretion rate for each hour of the day was calculated. The excretion profiles were characterized by total amount of MT6s excretion/24 h/kg body mass, amount of excreted MT6s during 6 h of maximum excretion (MAX 6h), and start time of the maximum excretion (start MAX 6h). There were significant positive correlations between serum melatonin AUC value and total excretion of MT6s/body mass, between serum melatonin amplitude and urinary MAX 6h, and between melatonin half-rise time and start MAX 6h; one patient on phenobarbital medication was out of line. The serum melatonin profiles of the patients were classified by comparing them with those of matched healthy volunteers (low-, normal-, or high secretors, normal or delayed rhythm). Similarly, the parameters of MT6s profiles were compared with those obtained from healthy controls, and the patients were reclassified as normal or aberrant. The classifications based on serum melatonin and urinary MT6s measurements were mostly concordant. The daily pattern of urinary MT6s excretion reliably reflected the phase of the serum melatonin rhythm irrespective of the medications, but in some cases, the total amount of excreted MT6s was lower than expected based on serum melatonin measurements.

The effect of single oral doses of zopiclone on nocturnal melatonin secretion in healthy male volunteers

The effects of single oral doses of zopiclone and temazepam were investigated in eight healthy male volunteers using a single blind, placebo controlled cross over study. Doses of zopiclone were 7.5 and 15 mg while the dose of temazepam was 20 mg. Each dose was separated by at least a one-week washout period. For each subject the dim light melatonin onset (DLMO) was determined on a screening night and the drugs were administered at the time of the DLMO. Melatonin concentrations were determined by radioimmunoassay from plasma samples collected throughout the night. Both temazepam and zopiclone tended to reduce the amount of melatonin secreted, as determined by the area under the plasma concentration time curve. The differences from placebo were not statistically significant (F 3.31 = 1.07, P > 0.1). Similarly a repeated measures analysis of variance on the plasma concentration-time curves did not show any statistically significant differences between drugs and placebo (F 3.28 = 1.15, P > 0.1). There was no evidence from this study of a phase shifting effect of the drugs used. The reasons for the lack of effect on melatonin may be due to the differences in potency of the interaction of these drugs with the GABA-benzodiazepine-chloride ion channel.

Suppression of nocturnal plasma melatonin levels by evening administration of sodium valproate in healthy humans

To investigate the role of gamma-aminobutyric acid (GABA) in the modulation of human melatonin production, we studied the effects of the acute administration of the GABAergic drug, sodium valproate (VAL), on nocturnal blood melatonin levels in healthy subjects. To this purpose, 4 healthy men and 3 healthy women, aged 24-33 years, underwent three experimental sessions in which they received orally 400 mg VAL, 800 mg VAL, or placebo, in random order, according to a double-blind design. The drug administration was done at 19:00 hours; thereafter, blood samples were collected over the night, in dark conditions with the help of a red light. As compared to placebo, VAL, at the dosage of both 400 and 800 mg, significantly suppressed nocturnal blood melatonin levels, the higher dose being slightly more effective than the lower one. The maximum suppression coincided with the highest plasma levels of valproic acid. These findings support the view that endogenous GABA may participate in the modulation of the activity of the human pineal gland.