Hypnotic prescriptions in a university hospital: Analysis of data from the computer-ordering system
Abstract
Abstract The computer-ordering system (COS) database was used to investigate hypnotic prescriptions issued to outpatients at various medical departments at the Dokkyo University School of Medicine. Hypnotics were prescribed for 3428 patients (1613 men, 1815 women), with a mean age of 56 years (range 8–91 years). The number of prescriptions was 3.5% of the total number of prescriptions (123 518). Although hypnotics were prescribed most often to patients in their 60s, generally, the incidence was higher for younger-aged patients. Physicians in all specialty areas tended to prescribe short-acting benzodiazepine hypnotics. The issuance of hypnotic prescriptions should be investigated to determine the prevalence of insomnia in various medical specialties.
INTRODUCTION
Insomnia is a major problem for people with sleep disorders. Approximately 20% of Japanese in modern society are reported to be insomniacs, of whom approximately 8.2% are taking hypnotics.1 Since a computer-ordering system (COS) was installed at the Dokkyo University School of Medicine in 1999, it has enabled drug prescriptions to be monitored. The COS database was used to investigate the prescription of hypnotics in various medical departments at the hospital.
SUBJECTS AND METHOD
We used COS (HOPE/EGMAIN for Windows™) to study the prescription of hypnotics to outpatients attending the hospital between September 1 and 30, 2000. The drugs were classified into two groups based on their duration of action and chemical structure. The numbers of patients prescribed hypnotics were grouped according to age and medical department.
RESULTS
Hypnotics were prescribed for 3428 patients (1613 men, 1815 women), with a mean age of 56 years (range 8–91 years). The hypnotic prescriptions comprised 3.5% of the total number of prescriptions (4375 of 123 518). The number of patients prescribed hypnotics was largest in the 60s age group, followed by those aged in their 70s, 50s, 40s, 30s, 20s, 80s, teens, and 90s. The numbers of patients, however, were not equal among the various age groups, whereby the 60s age group had the largest number. The ratio of patients prescribed hypnotics was calculated for each age group. The highest ratio was for patients in their 30s (5.7%; 483 of 8443) followed by patients in their 40s (4.9%; 596 of 12 210), 20s (4.9%; 367 of 7367), 60s (3.8%; 1058 of 27 704), 50s (3.6%; 788 of 21 878), 70s (3.1%; 806 of 25 608), 80s (2.5%; 180 of 7271), 90s (2.3%; 9 of 393) and teens (2.0%; 87 of 4296). Ultrashort-, short-, intermediate-, and long-acting drugs, respectively, were prescribed for 14.1%, 41.5%, 28.9%, and 15.5% of patients. Ultrashort- and short-acting drugs were prescribed mostly to middle- and old-aged patients, whereas intermediate-acting drugs were prescribed mostly to younger patients. The prescription rate for ultrashort- and short-acting hypnotics was highest at the departments of Internal medicine and Surgery, whereas the prescription rate of intermediate-acting hypnotics was highest at the Department of Psychiatry (Fig. 1). Benzodiazepin hypnotics and benzodiazepin tranquilizers were prescribed to the majority of patients, regardless of age, at the three departments of Internal medicine, Surgery, and Psychiatry. Barbital and non-barbital hypnotics were prescribed to some younger patients.
. The prevalence of hypnotic prescriptions in various hospital departments.
DISCUSSION
The study’s findings indicate that hypnotics are most often prescribed at the hospital to patients in their 60s, but that the incidence of prescription is higher for younger patients, which is consistent with results of a previous report.2 Physicians of all three specialties tended to prescribe short-acting benzodiazepine hypnotics. This selective use of hypnotics is explained in part by the fact that the incidence of adverse reactions with benzodiazepine hypnotics is low, whereas barbital hypnotics cause adverse reactions such as respiratory insufficiency and drug resistance. Of the benzodiazepin hypnotics, short-acting hypnotics are less likely to produce sedative hangover effects, such as daytime sleepiness and daytime behavioural impairment, the next day compared with long-acting ones. Short-acting hypnotics tend to be prescribed to elderly patients, presumably because they may experience excessive sedation or be injured in falls resulting from the hangover effects of drugs due to diminished drug metabolism and excretion, and because respiratory insufficiency and sleep apnea syndrome, if present, are exacerbated by long-acting hypnotics. In contrast, intermediate-acting hypnotics tended to be prescribed to younger patients, presumably because younger patients have fewer hangover drug effects. When hypnotic prescriptions were analysed according to medical specialty, ultrashort- and short-acting hypnotics were shown to be prescribed more commonly by internists and surgeons, whereas intermediate-acting ones tended to be preferred by psychiatrists; these results are consistent with those of a questionnaire survey carried out by Murasaki.3 Internists tend to use short-acting hypnotics in the combined treatment of insomnia, which often accompanies physical disorders and an underlying disease; whereas, psychiatrists choose intermediate-acting hypnotics for the treatment of frequent waking during the night, difficulty in maintaining sleep, and early morning wakening due to mental disorders.
