The impact of age on the hypnotic effects of eszopiclone and zolpidem in the guinea pig

Detrusor underactivity: Pathophysiological considerations, models and proposals for future research. ICI-RS 2013

AIMS

Detrusor underactivity, resulting in either prolonged or inefficient voiding, is a common clinical problem for which treatment options are currently limited. The aim of this report is to summarize current understanding of the clinical observation and its underlying pathophysiological entities.

METHODS

This report results from presentations and subsequent discussion at the International Consultation on Incontinence Research Society (ICI-RS) in Bristol, 2013.

RESULTS AND CONCLUSIONS

The recommendations made by the ICI-RS panel include: Development of study tools based on a system's pathophysiological approach, correlation of in vitro and in vivo data in experimental animals and humans, and development of more comprehensive translational animal models. In addition, there is a need for longitudinal patient data to define risk groups and for the development of screening tools. In the near-future these recommendations should lead to a better understanding of detrusor underactivity and its pathophysiological background. Neurourol. Urodynam. 33:591-596, 2014. © 2014 Wiley Periodicals, Inc.

Effects of eszopiclone and zolpidem on sleep-wake behavior, anxiety-like behavior and contextual memory in rats

At present, eszopiclone and zolpidem are the most commonly prescribed drugs for treating insomnia. Despite the established relationship between sleep disturbance and anxiety, it remains unknown whether targeted treatment for insomnia may affect acute anxiety. Therefore, the objective of this study was to examine the effects of three different doses (1, 3, and 10mg/kg) of eszopiclone and zolpidem on the states of sleep and wakefulness, levels of anxiety-like behavior, and long-term contextual memory in footshock-induced anxious rats. The results of this study demonstrated that the administration of eszopiclone and zolpidem both were equally effective in attenuating footshock stressor-induced suppression of slow-wave sleep (SWS). The administration of eszopiclone at 1mg/kg or zolpidem at 1 and 3mg/kg doses showed a tendency for attenuating stressor-induced suppression of REM sleep. However, the REM sleep attenuating effects of these drugs disappeared when they were administered at higher doses. The administration of eszopiclone at 3 and 10mg/kg doses and zolpidem at all three doses reduced the power of electroencephalographic theta band frequencies during wakefulness. In addition, the administration of eszopiclone at 1 and 3mg/kg doses suppressed stressor-induced anxiety-like behavior. The administration of zolpidem at 1, 3, or 10mg/kg doses was not effective in attenuating stressor-induced anxiety-like behavior. Contextual memory after administration of eszopiclone at 1mg/kg dose had no effects, but was reduced significantly with increased dosage. Contextual memory after administration of zolpidem, at all three doses, was severely disrupted. The results of this study suggest that eszopiclone at a low dose could be used effectively to control anxiety and anxiety-induced insomnia.

Zolpidem is a potent anticonvulsant in adult and aged mice

Zolpidem is a widely used hypnotic drug acting via benzodiazepine binding sites on GABA(A) receptors. Several studies suggested that zolpidem might have better anticonvulsant potency than previously thought. To compare the sedative and anticonvulsant potency of this drug, we studied in male mice the influence of zolpidem (0.1-10 mg/kg i.p.) on ambulatory locomotor activity (a measure of sedation) and on the threshold for myoclonus, clonic and tonic seizures, as well as death, in response to i.v. infusion of pentylenetetrazole (PTZ, 4.4 mg/min). Because older people take zolpidem more often than young people and have a higher incidence of epilepsy, we also compared the sedative and anticonvulsant properties of low doses of this drug (0.1 and 1 mg/kg i.p.) between adult (3 months) and aged (13 months) mice. Zolpidem in doses of 0.3-10 mg/kg decreased locomotion, as quantified by recording interruptions of infrared beams during 10 min, and in doses of 1-10 mg/kg increased the threshold for PTZ-induced seizures and death. The effect of zolpidem against tonic seizures was greater than against two other seizure components and death. In control aged mice the threshold for PTZ-induced myoclonus, clonic seizures and death was lower than in adult mice, while the locomotor activity was not different. In adult and in aged mice zolpidem in a dose of 1 mg/kg decreased locomotion and elevated the threshold for PTZ-induced seizures and death. Neither of these effects was age-dependent. The results suggest that in addition to strong sedative activity zolpidem has potent anticonvulsant properties.