Psychotropic drugs, aging and community care

[Association between anxiolytic and antidepressant consumption and psychiatric symptoms in the elderly]

INTRODUCTION

Many studies have reported excessive consumption of psychotropic drugs in the elderly but none have related psychotropic drug use to psychiatric symptoms and sleep disorders in community-dwelling patients aged more than 65 years old in Spain.

MATERIAL AND METHODS

We performed a cross sectional study in a representative sample (9,739 persons) from the population aged more than 55 years old in the city of Zaragoza in 2001. A total of 3,714 persons aged more than 65 years old were interviewed. The data belonged to the ZARADEMP project.

RESULTS

The mean age of the sample was 76.9 years (59.2% women and 40.8% men). Anxiolytics or antidepressants were consumed by 22.6% of the sample. A diagnosis of depression was made in 12.9%, anxiety in 1.6% and insomnia in 36%. We found high consumption of anxiolytics, especially in persons with depression (42.2%) and low consumption of antidepressants, especially in persons with a diagnosis of depression (15.4%) and in those with depressive symptoms (8.2%).

CONCLUSIONS

A correct psychiatric diagnosis is essential before psychotropic drugs are used to ensure appropriate treatment of the elderly with psychiatric symptoms.

Newer psychotropic medication use in nursing home residents

OBJECTIVE

To evaluate the use of newer psychotropic agents in nursing home residents in the era of new Health Care Financing Administration (HCFA) guidelines.

DESIGN

Retrospective chart review of referrals to an on-site geriatric psychiatry service in seven Eastern Massachusetts facilities during 1995-1996.

SUBJECTS

The 298 patients examined included 226 women and 72 men with a mean (SD) age of 81.9 (9.4) years.

MEASUREMENTS

Patient demographics, psychiatric history and medical diagnoses, prescribed medication information, and mental status examination results were recorded systematically. Descriptive statistics of demographics, medication use, and dosing were generated, and comparative analyses were performed by chi-square, ANOVA, and Tukey's tests.

RESULTS

Overall, 69% of subjects were taking at least one psychotropic medication. Although benzodiazepines (32%) and antipsychotics (42%) were used by a large portion of subjects, antidepressants (61%) were the most commonly prescribed psychotropic, with 53% taking serotonin reuptake inhibitors. The atypical antipsychotic, risperidone, accounted for more than 30% of antipsychotic prescriptions. Low rates of anticholinergic use and low doses and rates of tricyclic antidepressant use were found in Alzheimer's disease patients. Mean dosing of the psychotropic agents fell within HCFA guidelines.

CONCLUSIONS

Newer-generation psychotropics have had a significant impact on the prescribing practices of primary physicians in treating nursing home residents. Of clinical importance is the high rate of antidepressant use in a population that has traditionally received inadequate pharmacotherapy for depression. More studies are needed to examine a shift to the use of other psychotropic drugs in this population in the post-HCFA area.

The role of cytochrome P450 enzymes in hepatic and extrahepatic human drug toxicity

The human cytochrome P450 enzyme system metabolises a wide array of xenobiotics to pharmacologically inactive metabolites, and occasionally, to toxicologically active metabolites. Impairment of cytochrome P450 activity, which may be either genetic or environmental, may lead to toxicity caused by the parent compound itself. In practise, this usually only applies to drugs that have a narrow therapeutic index and when their clearance is critically dependent upon the fraction normally metabolised by that pathway. P450 enzymes may also convert the drug to a chemically reactive metabolite, which, if not detoxified, may lead to various forms of hepatic and extrahepatic toxicity, including cellular necrosis, hypersensitivity, teratogenicity, and carcinogenicity, depending on the site of formation and the relative stability of the metabolite, and the cellular macromolecule with which it reacts. Variation in the regulation and expression of the drug metabolising enzymes may play a key role in both interindividual variation in sensitivity to drug toxicity and tissue-specific damage. Avoidance of toxicity may be possible in rare instances by prediction of individual susceptibility or by designing new chemical entities that are metabolised by a range of enzymes (both cytochromes P450 and others) and do not undergo bioactivation.