Effects on postural oscillation and memory functions of a single dose of zolpidem 5 mg, zopiclone 3.75 mg and lormetazepam 1 mg in elderly healthy subjects. A randomized, cross-over, double-blind study versus placebo.
OBJECTIVE
In elderly patients, both falls and impaired memory are considerable medical problems. Hypnotics, which are frequently administered to this patient group for the treatment of insomnia, should ideally not impair equilibrium or memory functions. This double-blind, randomised, four-way, cross-over study investigated the effects of frequently prescribed hypnotics from different classes on postural oscillation and memory under real life conditions. Zolpidem 5 mg, zopiclone 3.75 mg, lormetazepam 1 mg (i.e. usual starting doses in elderly) or placebo were administered at night to 48 healthy elderly volunteers aged 65 years or more. The study included four treatment periods separated by wash-out periods of at least 1 week.


METHODS
Psychomotor tests up to 9 h or 10 h after drug intake included, for attention and body sway, clinical stabilometric platform (CSP) tests, simple reaction time (SRT), and the critical tracking test (CTT); for memory, the learning memory tasks (LMT) and the Sternberg memory scanning test (mean reaction time [MRT] and percentage of correct answers) were used. For subjective sleep evaluation the Leeds sleep evaluation questionnaire (LSEQ) and for sedation a visual analogue scale (VAS) were used. For safety evaluations, adverse events (AEs) were recorded.


RESULTS
The results demonstrate that compared with placebo, the active drugs increased body sway (area eyes open and closed in the CSP); however, this effect disappeared after 5 h with zolpidem, while it disappeared only after 8 h with lormetazepam and zopiclone. All three drugs did not affect attention assessed by the SRT and CTT. Concerning memory, Sternberg MRT at 9 h was not significantly different up to 5 digits for all groups in comparison with placebo, while for 6 digits it was significantly increased with lormetazepam and zopiclone. In the LMT, an impairment of performance was observed with lormetazepam relative to both zolpidem and placebo.


CONCLUSIONS
The safest compared drug with regard to body sway was zolpidem, because of its short-lasting effect. In addition, zolpidem did not show any significant effect on memory functions, in the present dose comparison.
Allain
Hervé
H
Laboratoire de Pharmacologie Expérimentale et Clinique, Université de Rennes 1, Faculté de Médecine, 2 rue du Pr Léon Bernard, CS 34317, 35043 Rennes Cedex, France. herve.allain@univ-rennes1.fr
Bentué-Ferrer
Danièle
D
Tarral
Antoine
A
Gandon
Jean-Marc
JM
D000368:Aged; D001288:Attention / Q000187:drug effects; D053961:Azabicyclo Compounds; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects*; D008140:Lorazepam / Q000008:administration & dosage / Q000009:adverse effects* / Q000031:analogs & derivatives*; D008297:Male; D008568:Memory / Q000187:drug effects*; D010879:Piperazines / Q000008:administration & dosage / Q000009:adverse effects*; D010919:Placebos; D004856:Postural Balance / Q000187:drug effects*; D011597:Psychomotor Performance / Q000187:drug effects; D011725:Pyridines / Q000008:administration & dosage / Q000009:adverse effects*; D011930:Reaction Time / Q000187:drug effects; D012678:Sensation Disorders / Q000139:chemically induced; D012890:Sleep / Q000187:drug effects; D000077334:Zolpidem
D053961:Azabicyclo Compounds; D006993:Hypnotics and Sedatives; D010879:Piperazines; D010919:Placebos; D011725:Pyridines; C515050:zopiclone; D000077334:Zolpidem; C023842:lormetazepam; D008140:Lorazepam