Adverse effects of antidepressants in the elderly

Impact of age and CYP2D6 genotype on exposure of zuclopenthixol in patients using long-acting injectable versus oral formulation-an observational study including 2044 patients

PURPOSE

Zuclopenthixol is an antipsychotic available as oral and long-acting injectable (LAI) formulations. The aim of this study was to investigate the effect of age on zuclopenthixol exposure during oral and LAI administrations without and with adjustment for CYP2D6 genotype.

METHODS

Data on serum concentrations of zuclopenthixol and CYP2D6 genotype (available for 28.2% of the population) from patients using oral or LAI zuclopenthixol were included retrospectively from a therapeutic drug monitoring service during the period 2005-2019. As a measure of exposure, dose-adjusted serum concentration (C/D ratio) was used. Based on age, patients were grouped to older (≥ 65 years) or younger (18-64 years). Linear mixed model analyses without and with adjustment for CYP2D6 genotype were used.

RESULTS

Serum concentrations of zuclopenthixol from 1145 (14.1% older) and 899 patients (24.6% older) in the LAI and oral groups were included, respectively. Compared with younger patients, older patients had a higher C/D ratio of zuclopenthixol for LAI (+ 25-33%, p < 0.001) and oral formulation (+ 25-29%, p ≤ 0.003) without and with adjustment for CYP2D6 genotype. The doses were lower in older versus younger patients (oral: - 30%; LAI: - 20%; p < 0.001). Compared with the younger LAI users without reduced CYP2D6 function, a higher C/D ratio was observed in the older LAI users with reduced CYP2D6 function (+ 104%, p < 0.001).

CONCLUSION

The present study showed that zuclopenthixol exposure increases in older patients and that the older LAI users with reduced CYP2D6 function are exposed to high serum concentrations. Also, the present study showed that similar dose reductions are required for oral and LAI users.

Cross-National Comparisons of Antidepressant Use Among Institutionalized Older Persons Based on the Minimum Data Set (MDS)

On a examiné l'usage des antidépresseurs dans des échantillons provenant d'établissements de soins de longue durée de Toronto (Canada), Sapporo et Naie (Japon), Reykjavik (Islande) et Prague (République tchéque). C'est seulement en Islande que la majorité des résidents souffrant de dépression recevaient des antidépresseurs. Le taux de dépression et l'usage des antidépresseurs sont généralement faibles au Japon. On a constaté un écart important entre le diagnostic de dépression et le comportement dépressif en République tchèque. Dans tous les pays examinés, environ la moitié des utilisateurs d'antidépresseurs ne présentent pas de symptômes évidents de dépression. Dans certains pays, l'usage des antidépresseurs était moins élevé chez les résidentes, chez les aîné(e)s plus âgés ou plus handicapés. La dépression est clairement sous-diagnostiqué en République tchèque mais les faibles taux de dépression au Japon sont plus difficiles à interpréter. Étant donné l'opinion largement répandue voulant que la dépressione passe souvent inaperçue et soit done mal soignée, les résultats de l'étude laissent entendre que l'on pourrait améliorer les mesures prises dans les cas de dépression grâce à des outils comme le MDS.

Assessment and management of pain in palliative care patients

BACKGROUND

Pain affects more than 70% of cancer patients but is often undertreated.

METHODS

The authors review and present methodologies to maximize proper palliative approaches to this symptom for the majority of patients.

RESULTS

The World Health Organization's stepwise guide to pain control serves as an excellent basis for management. Around-the-clock dosing, using adjuvant treatments, and using noninvasive routes of administration provide good pain control for 80% of patients.

CONCLUSIONS

Barriers to effective pain control will be reduced as new JCAHO standards regarding pain control are implemented.

Use of prevalence and incidence measures to describe age-related prescribing of antidepressants with and without anticholinergic effects

To evaluate whether physicians avoid prescribing highly anticholinergic antidepressants (AAD) in the elderly, a population-based retrospectively data analysis was performed using databases from a Dutch health insurance company. Data collected on approximately 240,000 persons covered the period from 1 July 1993 to 1 January 1996. The prevalence and the incidence (number of new starters) of antidepressant use was measured over 1994 and 1995. Use of AAD was proportionally higher in the elderly in terms of both prevalence and incidence rates; the ratio of starters of AAD versus starters of non-AAD in 1994 increased steadily with age (from 0.54 in the age group 20-29 to 1.15 in the age group 60-69). In 1995 these incidence ratios decreased (0.41 to 0.99, respectively); however, the decrease was higher in the younger age groups. The data indicate that in the population studied, physicians do not refrain from prescribing highly anticholinergic agents to older patients despite their potential adverse drug reactions in this age group. This study also indicates that prevalence and incidence rates can be extracted from reimbursement data and give insight into actual prescribing practices.

Selective serotonin reuptake inhibitors in older patients. A tolerability perspective

Depression is a serious illness that is common in the elderly but which is frequently overlooked. Management is complicated by physiological changes associated with aging, the presence of comorbid physical illness, and compliance problems; these factors must be taken into account when selecting an appropriate antidepressant. The well known problems associated with the tricyclic antidepressants (TCAs) [i.e. their unwanted anticholinergic, adrenergic and histaminergic effects], which are troublesome in younger patients, can have serious consequences for elderly depressed patients. The TCAs can cause symptoms that worsen concomitant physical illness, which is frequently present in the elderly, and their cardiotoxicity in overdose is of concern in both younger and older patients. The selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors have been shown to be as efficacious as the TCAs in the general depressed population, but to lack the anticholinergic adverse effects and cardiotoxicity associated with those drugs. Their increased safety and tolerability makes them a preferred treatment for depressed elderly patients.

Venlafaxine. A review of its pharmacology and therapeutic potential in depression

Venlafaxine is a phenylethylamine derivative which facilitates neurotransmission in the brain by blocking presynaptic reuptake of serotonin (5-hydroxytryptamine: 5-HT) and noradrenaline (norepinephrine). Clinical data from patients with major depression are consistent with the favourable efficacy and tolerability profile of venlafaxine predicted by pharmacodynamic studies. In patients with major depression, venlafaxine 75 to 375 mg/day administered for 6 weeks was significantly more effective than placebo, and at least as effective as imipramine, clomipramine, trazodone or fluoxetine. Venlafaxine is well tolerated, being associated with fewer anticholinergic and CNS adverse effects than tricyclic antidepressants. Unlike the tricyclic antidepressants, venlafaxine does not appear to significantly affect cardiac conduction, although there have been a few reports of modest increases in blood pressure, particularly after high doses of the drug. In conclusion, wider clinical experience is required to better characterise and confirm potential advantages of venlafaxine compared with other antidepressant agents. These advantages may include a rapid onset of action and reduced propensity to cause anticholinergic effects and cardiotoxicity compared with tricyclic antidepressants. Nevertheless, at this stage venlafaxine offers a more attractive treatment option than tricyclic antidepressants for patients with major depression, primarily because of its good overall tolerability profile.

Acute and subchronic effects of nefazodone and imipramine on highway driving, cognitive functions, and daytime sleepiness in healthy adult and elderly subjects

The acute and subchronic effects of two dosages of a new serotonergic antidepressant, nefazodone, and those of the tricyclic imipramine were examined in a double-blind, crossover, placebo-controlled study. Twenty-four healthy subjects from two age groups (12 adults and 12 elderly from both sexes) received the four treatments (nefazodone, 100 and 200 mg twice daily; imipramine, 50 mg twice daily; and placebo) for 7 days with a 7-day washout period. Measurements were performed after the morning doses on day 1 and day 7. These included a standard over-the-road highway driving test, a psychomotor test battery, and sleep latency tests. Blood samples were taken on both days and analyzed to determine concentrations of parent drugs and their major metabolites. The main results showed that the reference drug, imipramine, had a detrimental effect after a single dose on lateral position control in the driving test, primarily in the adult group, that diminished after repeated dosing. Minor impairment on psychomotor test performance was found with both days. On the other hand, a single administration of both doses of nefazodone did not impair highway driving performance (even showed some improvement) and had no or only minor effects on psychomotor performance. After repeated dosing, nefazodone 200 mg twice daily (but not the 100-mg dose) produced slight impairment of lateral position control; dose-related impairment of cognitive and memory functions was found. The effects of nefazodone were generally in the same direction in both age groups. Significant correlations were found between steady-state concentrations of nefazodone in plasma (200-mg, twice-daily condition) as well as imipramine, and reaction time changes in a memory scanning task. Neither drug appeared to induce daytime sleepiness as measured by the sleep latency tests.

Fluoxetine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in older patients with depressive illness

The selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor fluoxetine is an effective antidepressant in elderly patients. Its efficacy is similar to that of other frequently used antidepressants, such as the tricyclic antidepressants. However, compared with the tricyclic antidepressants, fluoxetine has a more favourable tolerability profile and is less toxic in overdose. It is associated with fewer anticholinergic, cardiovascular and CNS adverse events, but greater numbers of gastrointestinal adverse events than have been reported for the tricyclic antidepressants. This is important in elderly patients who are more at risk of developing central anticholinergic and cardiovascular effects than are younger patients. Therefore, while its position relative to other selective serotonin reuptake inhibitors requires investigation, fluoxetine represents a major advance over tricyclic antidepressant agents in the treatment of elderly patients with depression, predominantly because of its favourable tolerability profile.