Absence of orthostatic hypotension in depressed patients treated with bupropion

Clinical trials of potential antidepressants: to what extent are the elderly represented: a review

BACKGROUND

There is widespread use of antidepressants in the elderly population. The principle of treatment of depression, however, is derived mostly from studies employing young adults and healthy elderly. This article reviews the literature on the extent to which the elderly are represented in clinical trials of potential antidepressants.

METHOD

Medline search of relevant articles of clinical trials of potential antidepressants.

RESULTS

The maximum age of inclusion for most clinical trials was 65 years. The highest age reported for depressed subjects was 90 years. There was no clear consensus on who were considered to be elderly; clinical trials conducted on the elderly included subjects who were 50, 55, or 60 years and over. Pharmacological studies on healthy subjects were most often done on young adults, age range 18 to 65 years. The period of study was relatively shorter for clinical trials done on elderly subjects. There was however, no difference in the exclusion or inclusion criteria between studies done in young and elderly subjects.

CONCLUSIONS

Elderly subjects aged 75 years and over were clearly underrepresented in the clinical trials of potential antidepressants. For drugs that are used by the elderly, in its pivotal studies for registration, the inclusion of at least 25% of subjects aged 75 years and over is recommended.

Evaluation of bupropion hydrochloride: the first of a new class of atypical antidepressants

Bupropion hydrochloride is a new antidepressant that differs clinically and pharmacologically from the tricyclic antidepressants and the monoamine oxidase inhibitors. Pharmacokinetically, bupropion is an intermediate-lived drug with a half-life of about 12 hours. Its antidepressant activity in man has been demonstrated in double-blind, placebo and active drug-controlled studies. Onset of antidepressant action occurs in one to three weeks. Bupropion has a greater effect on the neuronal reuptake of dopamine than of other biogenic amines. At a recommended dose of 450-600 mg/day, the side effect profile of bupropion also distinguishes it from other antidepressants. It does not bind to cholinergic receptors in vitro at clinically relevant concentrations and does not produce appreciable autonomic side effects. The exception is dry mouth, which is reported in 13% of patients. The mechanism underlying this effect is unclear. Bupropion is devoid of cardiovascular effects (e.g., impaired intracardiac conduction, reduced myocardial contractility, decreased peripheral resistance, orthostatic hypotension) in both human and animal studies. The drug is nonsedating and antagonizes the effects of commonly used sedatives, such as alcohol and diazepam. It does not produce weight gain. In susceptible patients, activating effects can occur. Given this profile, bupropion should be less toxic than conventional antidepressants when taken in overdoses; however overdose experience with the drug is limited.