Commentary on review by Woods and Winger. Benzodiazepines: long-term use among patients is a concern and abuse among polydrug abusers is not trivial

Taking Policy Action to Reduce Benzodiazepine Use and Promote Self-Care Among Seniors

This article reviews current knowledge on the risks and benefits of benzodiazepine use for seniors and addresses potential policies that could be made to reduce use and support sentors' mental health. Although seniors are only 12% to 15% of the population, they consume between 35% and 52% of all benzodiazepines prescribed in Canada and the United States. Despite significant long-term use among seniors, relatively few studies demonstrate the efficacy of more than short-term use for anxiety and insomnia. There is significant data to suggest that use is associated with increased potential for injury, cognitive and memory deficits, and a dependency syndrome. This article argues that the current controversy rests not so much in the scientific data but in the willingness of clinicians to interpret and act on that information. As internationally developed guidelines for practice suggest that benzodiazepine treatment for anxiety and insomnia may not be without risks, other first-line treatments should be developed.

Mental disorders associated with benzodiazepine use among older primary care attenders--a regional survey

BACKGROUND

Benzodiazepines (BDZs) are among the most commonly prescribed drugs in the elderly and their use is often too prolonged according to current international guidelines.

METHODS

We investigated the pattern of use of BDZs among 65- to 84-year-old attenders at 40 Italian primary care practices who answered positively in a questionnaire on the use of anxiolytic/hypnotic drugs and successfully completed the PRIME-MD questionnaire. The survey lasted 6 months, from February to July 2001.

RESULTS

Of the 1,156 subjects who completed the PRIME-MD, 748 subjects were positive for at least one psychiatric diagnosis. A depressive disorder was present in 36.5% of all PRIME-MD completers and in about one-third of cases represented by major depression, whereas anxiety disorders, somatoform disorders and alcohol abuse accounted for 18.2%, 8.1% and 1.7% of all PRIME-MD completers, respectively. Most patients were first prescribed BDZs by their General Practitioners (GPs) for each diagnostic group. However, patients with pure anxiety started BDZ treatment during hospitalisation more often (19.7%) than patients with depressive disorders (13.7 %). Moreover, patients with comorbid anxiety and depressive disorders (CADD) were most likely to receive their first BDZ prescription from a psychiatrist (15.7 %). Sleep disturbances were present in at least 50% of cases (and up to 86 %) in each diagnostic group. About 75% of prescriptions concerned anxiolytic BDZ or medium/long-acting BDZ. Most patients with anxiety, CADD and depression used night-time BDZ (65.2%, 56.9 % and 60.5%, respectively). The prevalence of chronic use of BDZs was equally high in all categories of psychiatric disorder (about 90 % for each), showing that the vast majority of patients, irrespective of the diagnosis, had been using BDZs for years.

CONCLUSIONS

BDZs are widely prescribed for elderly people by their GPs, often for a considerable length of time. The evidence that many BDZ consumers suffer from a depressive or an anxiety disorder, or both, could be a starting point for encouraging a rational prescription in accordance with international guidelines.

Use and abuse of the benzodiazepines

Since chlordiazepoxide was introduced in 1961, the benzodiazepines have had many important roles in the pharmacotherapy of various disorders. This drug class for the central nervous system has been considered one of the safest in use for 35 years, especially when the benzodiazepines are compared with the barbiturates they often replaced. The objective of this article is to provide an update on the availability and distribution of benzodiazepines around the world and to discuss their most common clinical applications. Adverse effects of benzodiazepines, observed after long-term therapeutic use and after overdoses, are also presented. Triazolam is discussed because this benzodiazepine was removed from the market by regulatory authorities in the United Kingdom in 1991. Benzodiazepines will continue to have an important role in clinical medicine. Their clinical use, however, should be monitored more closely because of the greater awareness of their adverse effects after long-term use and because of the potential for misuse and abuse.

Addiction to benzodiazepines

Benzodiazepines are sedative hypnotic medications that can induce a state of dependence. Dependence however is not the same as addiction. The development of dependence is a predictable phenomenon, influenced by dose, duration of treatment, and a number of other factors including individual characteristics of the benzodiazepine user. It is unclear whether there are meaningful differences among benzodiazepines in producing a state of dependence. Benzodiazepine dependence is also characterized by a predictable discontinuation syndrome. Benzodiazepines are rarely abused by non-substance abusers. The regulation of benzodiazepines although the legitimate therapeutic use has been significantly reduced.

Patterns of hypnotic drug prescription in Italy. A two-week community survey

BACKGROUND

In Italy a number of studies have been published on psychotropic drug use in general practice and community settings. However, the present study is the first Italian study to focus on hypnotic drug prescriptions in a large community sample.

METHOD

Data were collected from 145 of the total of 404 pharmacies of five large cities in north-eastern Italy. All consecutive patients presenting a prescription for a hypnotic drug were interviewed by the pharmacists during a two-week period.

RESULTS

The pharmacists interviewed 7/44 consecutive patients. The highest prevalence of prescriptions for hypnotic drugs was found in the elderly and in women. The majority (96%) of prescriptions were for benzodiazepines, with lorazepam and triazolam accounting for 50%. Short-acting and ultra-short-acting benzodiazepines were more frequently prescribed for sleep induction by general practitioners (GPs) than by psychiatrists and other physicians. Frequently the benzodiazepine used as a hypnotic was also prescribed for day time sedation. Approximately 72% of subjects reported they had been taking the prescribed drug for one year or more.

CONCLUSIONS

In Italy benzodiazepines are the most frequently prescribed drugs for sleep induction; as they are widely prescribed for elderly people by GPs often for long periods of time, educational programmes and guidelines on the rational use of benzodiazepines in general practice are needed.

The behavioural and neuronal effects of the chronic administration of benzodiazepine anxiolytic and hypnotic drugs

Benzodiazepine anxiolytic and hypnotic drugs are some of the most widely prescribed drugs in the Western world. Despite this fact, the mechanisms that underlie the development of tolerance to, and dependence upon, benzodiazepines are poorly understood. The aim of this review is to summarize and critically evaluate the experimental evidence relating to the chronic behavioural and neuronal effects of benzodiazepines. Behavioural studies in animals generally indicate that tolerance gradually develops to the muscle relaxant, ataxic, locomotor and anticonvulsant effects of benzodiazepines. The evidence relating to the development of tolerance to the anxiolytic effects of benzodiazepines is less clear. The literature on the possible mechanisms of benzodiazepine tolerance and dependence is large, highly complex and difficult to interpret. The effect of chronic benzodiazepine treatment varies enormously as a function of the benzodiazepine used and the treatment schedule employed. Many studies have demonstrated a down-regulation of benzodiazepine binding sites, although affinity is usually unchanged. The evidence relating to the number and affinity of GABAA binding sites is unclear. Some studies suggest that chronic benzodiazepine administration results in a reduction in the number of Cl- channels associated with the GABAA receptor complex, although it is not clear that the efficacy of the GABA binding site in operating the Cl- channel necessarily changes. There is, however, substantial evidence to support the hypothesis that chronic benzodiazepine treatment results in a reduction in the coupling between the GABAA and benzodiazepine binding sites (the "functional uncoupling hypothesis"). Although some electrophysiological studies suggest that chronic benzodiazepine treatment results in a subsensitivity to GABA, this effect seems to be highly area-specific.

Effects of several benzodiazepines, alone and in combination with flumazenil, in rhesus monkeys trained to discriminate pentobarbital from saline

The purpose of the present study was to further investigate the relationship between the DS effects of PB and those of benzodiazepines (BZs) and to begin to collect pharmacological information concerning receptor mechanisms involved in this behavioral effect of BZs. Rhesus monkeys (n = 3), trained to discriminate pentobarbital (PB; 10 mg/kg, IG) from saline under a discrete-trials shock avoidance procedure, were given IG diazepam (0.3-10 mg/kg), chlordiazepoxide (1.0-30 mg/kg), or etizolam (0.3-10 mg/kg) alone and in combination with flumazenil (0.01-1.7 mg/kg, IM). Flumazenil was administered 10 min prior to the administration of saline, PB or the BZs. All three BZs fully substituted for PB in all monkeys. Diazepam was the most potent with a mean ED50 of 0.81 mg/kg (SEM = 0.04) while chlordiazepoxide was the least potent (mean ED50 = 5.78 mg/kg, SEM = 1.22 mg/kg). The ED50 for etizolam was 1.22 mg/kg (SEM = 0.37 mg/kg). Pretreatment with flumazenil (0.01-1.0 mg/kg) resulted in a dose-related parallel shift to the right in the dose-response function for PB-appropriate responding in all monkeys for all three BZs. The mean (n = 3) pKB value with 0.1 mg/kg flumazenil was 6.51 (SEM = 0.42) for diazepam and 6.57 (SEM = 0.17) for chlordiazepoxide. This value could not be calculated for etizolam because only one monkey was tested with 0.1 mg/kg flumazenil. However, the mean pKB for etizolam considering all monkeys and all doses of flumazenil was 6.58 (SEM = 0.47). Apparent pA2 values for flumazenil with diazepam were 6.02 for one monkey and 7.11 for another. All three BZs tended to increase average latency to respond. Apparent pKB and pA2 analysis may prove useful for elucidating receptor mechanisms involved in the behavioral effects of BZs.