Benzodiazepines in the elderly

Sex differences in the burying behavior test in middle-aged rats: effects of diazepam

The full behavioral profile displayed during the burying behavior test was studied in middle aged (11-14 months) males, females with irregular estrous cycles, and females in persistent diestrus, with and without diazepam (0.5-2.0mg/kg). Ambulation and motor coordination were also tested to discern behavioral changes from general motor alterations. Without diazepam treatment, middle-aged males showed longer burying behavior latencies, more prod explorations and less freezing than both groups of females. Untreated middle aged males also showed less cumulative burying and more immobility compared to females with irregular cycles. None of the parameters showed any difference between the female groups. Diazepam (0.5 and 1.0mg/kg) increased burying behavior latency in females, but had no effect on any parameter in middle aged males. However, a higher dose (2.0mg/kg) of diazepam increased immobility, freezing and the number of prod shocks and decreased prod explorations and groomings, but impaired motor coordination in males. In contrast with young males and females, diazepam at any dose reduced cumulative burying. Data are discussed on the bases of (1) sex and age differences in burying behavior and on (2) the anxiolytic-like action of diazepam and its side effects.

Age-related alterations in GABAA receptor subunits in the nonhuman primate hippocampus

Pharmacological studies have documented that altered drug responses, particularly to benzodiazepines, are common in elderly populations. While numerous factors may contribute to changes in drug response, age-related alterations in the molecular composition of GABA(A) receptors may be a key factor in regulating these responses. We employed quantitative densitometry to examine the cytological features and density of highly prevalent hippocampal GABA(A) receptor subunits (alpha1 and beta2/3) in young and aged rhesus monkeys. alpha1 and beta2/3 subunit immunostaining was differentially distributed throughout the hippocampus. In addition, beta2/3 immunolabeling in aged monkeys was characterized by marked intersubject variability in labeling intensity, with dramatic reductions present in 3 of 5 samples. alpha1 immunolabeling in aged monkeys was significantly reduced in the CA2 and CA3 subregions, and in hilus/polymorphic layer of the dentate gyrus. Collectively, our findings demonstrate that not only are GABA(A) receptor subunits differentially distributed throughout the hippocampus, but they are also differentially altered with increased age--changes that may have an important impact on the binding properties of GABA(A) receptor pharmacological agents.

High daily doses of benzodiazepines among Quebec seniors: prevalence and correlates

BACKGROUND

Use of high daily doses of benzodiazepines is generally contraindicated for seniors. While both patient and physician factors may influence the use of high daily doses, previous research on the effect of patient factors has been extremely limited. The objectives of this study were to determine the one year prevalence of use of high daily doses of benzodiazepines, and examine physician and patient correlates of such use among Quebec community-dwelling seniors.

METHODS

Patient information for 1423 community-dwelling Quebec seniors who participated in the Canadian Study of Health and Aging was linked to provincial health insurance administrative data bases containing detailed information on prescriptions received and prescribers.

RESULTS

The standardized one year period prevalence of use of high daily doses of benzodiazepines was 7.9%. Use of high daily doses was more frequent among younger seniors and those who had reported anxiety during the previous year. Patients without cognitive impairment were more likely to receive high dose prescriptions from general practitioners, while those with cognitive impairment were more likely to receive high dose prescriptions from specialists.

CONCLUSION

High dose prescribing appears to be related to both patient and physician factors.

Continuous flumazenil infusion in preventing complications arising from severe benzodiazepine intoxication

A prospective, randomly controlled study was conducted to test the effect of continuous flumazenil infusion in preventing complications arising from severe benzodiazepine (BZ) intoxication. Patients who were believed to be suffering benzodiazepine intoxication and whose Glasgow Coma Scale (GCS) score was below 10 were enrolled after showing a clear-cut response to flumazenil 0.5 or 1 mg (an improvement by 4 or more on the GCS). The patients were consecutively enrolled and randomized into two groups: a continuous infusion group (CI, n = 50) who were immediately given flumazenil 0.5 mg/h for 5 hours, and a control group (CIN, n = 50). Age, sex, incidence of underlying disease, GCS score at several time points, and complication rate were compared in the two groups. Although the CI group had a higher GCS score at most time points, the complication rate did not significantly differ between the two groups (14 of 36 in the CI group v 12 of 38 in the CIN group, P = .684). A greater incidence of underlying disease and an older age seemed to contribute to the higher complication rates in both groups. Several patients (in both groups) resedated into deeper coma after showing an initial response to flumazenil or after the cessation of flumazenil infusion. For severe BZ intoxication, treatment with flumazenil infusion should still be considered skeptically and should not be recommended as routine management BZ-intoxicated patients with an underlying disease, an older age, and resedation into a deep comatose state after showing an initial response to flumazenil should be treated in an intensive care unit.

Cognitive side effects of medications

Iatrogenically induced cognitive deficits are common with pharmacological therapy. The deficits may range from gross encephalopathy with delirium to subtle subjective alterations (e.g., mood and perception of well being). The risks are increased for certain drug types, polypharmacy, the elderly, and patients with dementia or metabolic abnormalities. This review examines methodological concerns and the neuropsychological data on cognitive side effects across a variety of commonly used medicines in clinical practice.

Drug Therapy of Aggressive Behaviors Accompanying Dementia

Aggressive behaviors often accompany dementia in the elderly, institutionalized patient. These may include any number of verbal or physical acts, and range from swearing, threatening, to harming self, others, or property. Identifying specific target behaviors for treatment is important in selecting the appropriate therapeutic option. The major neurotransmitters involved in aggression include gamma-aminobutyric acid (GABA) and serotonin, which inhibit aggression, and dopamine, norepinephrine and acetylcholine, which increase it. Drug therapy for control of aggressive behaviors has traditionally included the antipsychotics and benzodiazepines. However, additional, newer therapies are also useful. Among these are the anticonvulsants carbamazepine and valproic acid, various beta-blocking agents, antidepressants, and buspirone. These medications may be needed when nondrug therapy for control of behavioral problems fails or is insufficient. Determining which behaviors are problematic and need treatment, knowing which medications are indicated for those problems, and noting contraindications for particular drug therapies will lead to the best therapeutic option for a given patient.

Psychotropic drug use in the medically ill. Part II

Underlying medical illness and drug interactions may make the use of psychotropic agents problematic in some physically ill patients. This overview, published in two parts, discusses six major classes of psychotropic medications (cyclic antidepressants, monoamine oxidase inhibitors, benzodiazepines, neuroleptics, lithium, psychostimulants, and carbamazepine) and examines their use in the setting of specific types of medical illnesses (e.g., cardiovascular, pulmonary, hepatic, and renal disease). Practical considerations in using psychotropic medications in medical-surgical patients--particularly those who are elderly or medically debilitated--will receive special emphasis.

A guide to benzodiazepine selection. Part II: Clinical aspects

To suit the specific needs of various clinical situations, selection of an appropriate benzodiazepine derivative should be based on consideration of their different pharmacokinetic and pharmacodynamic properties. Benzodiazepine derivatives that are rapidly eliminated produce the most pronounced rebound and withdrawal syndromes. Benzodiazepines that are slowly absorbed and slowly eliminated are most appropriate for the anxious patient, since these derivatives produce a gradual and sustained anxiolytic effect. Rapidly absorbed and slowly eliminated benzodiazepines are usually more appropriate for patients with sleep disturbances, since the rapid absorption induces sleep and the slower elimination rate may induce less tolerance to the sedative effect. Rational selection of a benzodiazepine for the elderly and for the suspected drug abuser is more problematic. The relevant pharmacokinetic and clinical considerations for these users are discussed. Certain derivatives may possess pharmacodynamic properties not shared by the entire benzodiazepine class; empirical studies have suggested the existence of anti-panic properties for alprazolam and clonazepam, antidepressant properties for alprazolam, and anti-manic properties for clonazepam and possibly lorazepam.

Psychotropic drug use in the medically ill: Part I

Underlying medical illness and drug interactions may make the use of psychotropic agents in some physically ill patients problematic. This overview, published in two parts, discusses six major classes of psychotropic medications (cyclic antidepressants, monoamine oxidase inhibitors, benzodiazepines, neuroleptics, lithium, psychostimulants, and carbamazepine) and examines their use in the setting of specific types of medical illnesses (e.g., cardiovascular, pulmonary, hepatic, and renal disease). Practical considerations in using psychotropic medications in medical-surgical patients, particularly those who are elderly or medically debilitated, receive special emphasis. In part I, the use of cyclic antidepressants, monoamine oxidase inhibitors, benzodiazepines, and buspirone are discussed.

Problems and pitfalls in the use of benzodiazepines in the elderly

Benzodiazepines are frequently prescribed for elderly patients living in the community and for those in hospitals and institutions. Their use is more prevalent in women. Prolonged use of benzodiazepines is particularly likely in old age for the treatment not only of insomnia and anxiety, but also of a wide range of nonspecific symptoms. Long term users are likely to have multiple concomitant physical and psychological health problems. The distinction between benzodiazepine anxiolytics and hypnotics is difficult and somewhat arbitrary, since the differences between the compounds are less than their similarities, especially in respect of adverse reactions. Despite their wide therapeutic range, elderly patients are particularly prone to adverse reactions to benzodiazepines. The incidence of unwanted effects, predominantly manifestations of central nervous system depression, has been found to be significantly increased in hospitalised elderly patients, particularly in the frail elderly. Studies on unwanted effects during long term use are scarce, but there is some evidence of tolerance to side effects. However, benzodiazepines have been found to be frequently implicated in drug-associated hospital admissions. There is suggestive evidence that benzodiazepines, especially compounds with long half-lives, may contribute to the falls which are a major health problem in old age. The incidence of benzodiazepine dependence in elderly patients is unknown. The features of benzodiazepine withdrawal in the elderly may differ from those seen in young patients; withdrawal symptoms include confusion and disorientation which often does not precipitate milder reactions such as anxiety, insomnia and perceptual changes. Problems due to both adverse reactions and to benzodiazepine withdrawal may easily be overlooked in multimorbid elderly patients, particularly in those suffering from disorders of the central nervous system. There are numerous studies on benzodiazepine pharmacokinetics indicating that alterations, especially in distribution and elimination of certain compounds, occur in old age. Benzodiazepines with oxidative metabolic pathways and longer half-lives are likely to accumulate with regular administration. However, changes in pharmacodynamics may be more important to explain altered responses to benzodiazepines in the elderly. Although information on pharmacodynamics is still limited, there is convincing evidence of increased pharmacodynamic response in the elderly which may be further accentuated by disease factors. Since the variability of pharmacological response increases with age and is not always predictable, there is good reason at least to start therapy at lower doses and to titrate dosages individually. This may also be appropriate for the newer benzodiazepines, irrespective of advantageous pharmacokinetics.(ABSTRACT TRUNCATED AT 400 WORDS)

Low-dose oral lorazepam administration in Alzheimer subjects and age-matched controls

Ten patients with Alzheimer's disease and ten age-matched normal controls were studied in a double-blind, placebo-controlled acute trial of 1 mg PO lorazepam to test the effects of low-dose benzodiazepine on memory and behavior in a mostly older population. Cognitive effects differed somewhat between Alzheimer patients and normal controls, with Alzheimer patients revealing predominantly "attentional" impairments and age-matched controls showing possible "disinhibition." Specifically, Alzheimer patients made more omission errors on a continuous performance task, whereas controls made more commission and intrusion errors with lorazepam versus placebo. This low dose of lorazepam (1 mg), which was associated with mild but statistically significant sedation in both groups, also produced no significant decrease in recent memory or in access to semantic memory. These cognitive findings contrast markedly to the reported effects of scopolamine on recent memory; therefore, supporting the idea that cholinergic interruption has a more specific effect on human memory and on learning than that of low-dose benzodiazepines. Further studies with a wider dose range of benzodiazepines are necessary to evaluate the possibility of differential sensitivity between Alzheimer patients and normal elderly controls.

Contributions of benzodiazepines to cancer therapy

We have reviewed the therapeutic effects of benzodiazepines employed as adjuncts to cancer treatment. These agents have been used primarily for alleviating or attenuating situational anxiety, insomnia, chemotherapy-induced nausea and vomiting, and anticipatory nausea and vomiting. Situational anxiety not corrected by psychosocial support, symptom control, or time may be successfully treated with benzodiazepines. Procedure-related anxiety, for example, that related to bone marrow biopsy, venipuncture, intrathecal therapy, and the insertion of subclavian and femoral catheters, is a serious problem that may be alleviated by the use of benzodiazepines. Insomnia not caused by a depression serious enough to warrant treatment with a tricyclic antidepressant also may be successfully treated with benzodiazepines. Many clinicians have found benzodiazepines to be useful adjuncts to a cancer chemotherapy regimen because of their anxiolytic, sedative, and amnesic properties and also because of their suspected antiemetic properties when these drugs are used in conjunction with known antiemetic agents. The ability of lorazepam to induce antegrade amnesia has proved particularly useful in alleviating anticipatory nausea and vomiting connected with repeated courses of cytotoxic chemotherapy. Furthermore, since benzodiazepines are relatively safe drugs, their continued and probably expanded uses as cancer therapy adjuncts can be anticipated.

Evaluation of temazepam and diphenhydramine as hypnotics in a nursing-home population

Seventeen nursing home residents with sleeping problems were enrolled in a randomized, double-blind, crossover trial of temazepam 15 mg, diphenhydramine (DPH) 50 mg, and placebo. Each drug was given for five consecutive nights with a 72-hour washout period between drugs. Subjects were assessed three times weekly with tests of psychomotor and cognitive function and four times weekly with observer sleep diaries and morning sleep questionnaires. Three subjects failed to complete the study. By report of the subjects, DPH resulted in shorter sleep latency than did placebo (t = 2.77, p less than 0.05). On the fifth night, use of DPH was associated with longer duration of sleep than temazepam (t = 2.88, p less than 0.05). No significant difference in tests of neurologic function was noted although, compared with placebo, subjects performed more poorly on seven of eight tests while taking temazepam and five of eight tests while taking DPH. Several instances of daytime hypersomnolence were noted in subjects taking temazepam and DPH, but none in subjects given placebo.

Diazepam, behavior, and aging: increased sensitivity or lower baseline performance?

Cognitive performance, psychomotor skills, and subjective reactions to diazepam and placebo were compared in 12 healthy, well-educated subjects in three age groups: 19-28, 40-45, and 61-73 years old. With only minor exceptions, the changes in performance caused by diazepam and age differences were statistically additive and noninteracting. Diazepam did not act synergistically in older individuals; the decrements in performance were about the same in all age groups. Baseline performance decreased with increasing age; middle-aged subjects performed more like older than younger subjects. A variety of tasks exhibited similar effects of aging and diazepam, i.e., when performance declined with increasing age, it was also reduced by diazepam.

Age-dependent enhancement of diazepam sensitivity is accelerated in New Zealand Black mice

Separate age groups of C57BL/6 and autoimmune New Zealand Black (NZB) mice were compared for diazepam-induced ataxia and barbiturate-induced loss of righting reflex. Between 1 and 3 months of age, both strains showed a similar age-related decrease in ED50 for diazepam-induced ataxia. However, between 3 and 12 months the decrease in ED50 was markedly greater in NZB mice. In contrast, age-related increases in the durations of loss of righting reflex following hexobarbital or barbital were similar in both strains. The results suggest that NZB mice show relatively accelerated age-related increases in sensitivity to benzodiazepine, but not to barbiturates.

A survey of psychotropic drug utilization by patients with advanced neoplastic disease

The utilization of psychotropic drugs in patients with advanced neoplastic disease was studied over a 14-month period. Eight hundred twenty-four (82.4%) of one thousand consecutively admitted patients were prescribed at least one psychotropic agent. Antipsychotic agents were prescribed for 61.3% and hypnotics for 55.8% of the total patient sample. Only one out of ten patients received an antidepressant medication. Significantly more psychotropic drugs were prescribed for the relatively younger patients (less than 50 years). Diphenhydramine, prochlorperazine, and haloperidol were the most frequently prescribed psychopharmacologic agents. The most common reasons for prescribing psychotropic medications were for psychologic distress, sleep disorders, and nausea and vomiting. Clinical consequences are discussed.

Long-acting and short-acting benzodiazepines in the elderly: kinetic differences and clinical relevance

A review of available information about the pharmacokinetics of pro-nor-diazepam-like compounds in the elderly shows substantial impairment of the metabolism compared to oxazepam-like benzodiazepines, which are metabolized with virtually no change in this age group. Results of clinical trials point in the same direction, although small numbers of patients, different criteria for measuring clinical benefit and adverse reactions and different dosages for various periods of time make the comparison difficult. Qualified clinical guidelines are mainly to reduce dosage and use oxazepam-like compounds in the elderly, but routine clinical practice does not seem to apply these recommendations. Further research is therefore needed, mainly in the area of clinical practice, to describe the 'real' situation of benzodiazepine prescription for in-patients and out-patients in terms of risk-benefit ratio of drug treatment and to monitor the changes occurring when a more rational approach is introduced as regards the need for treatment, dose and duration of treatment.