Antidepressant drug choice for first users in two regions in The Netherlands

Utilization patterns of antidepressants between 1991 and 2011 in a population-based cohort of middle-aged and elderly

BACKGROUND

In middle-aged and older patients in whom antidepressant use increased in last decades, patterns of use might be of concern The objective of this study was to investigate the patterns of prevalence, incidence and duration of antidepressant use in an ageing population.

METHODS

All participants (aged>45 years) from the population-based Rotterdam Study were followed from January 1st 1991 until death, loss to follow-up, or end of the study period (December 31st 2011). Antidepressant drug dispensing, based on pharmacy records, were subdivided into Tricyclic Antidepressants (TCAs), Selective Serotonin Reuptake Inhibitors (SSRIs) and other antidepressants. One-year prevalence, 5-year incidence and duration of antidepressant use were calculated.

RESULTS

Yearly prevalence of antidepressant use increased from 3.9% in 1991 to 8.3% of the population in 2011. The increase in SSRI use was 5.8-fold, whereas use of other antidepressants doubled and TCA use remained stable over time. Incidence of all antidepressants decreased from 23.9 to 14.2 per 1000 person-years between 1992 and 2011. The duration of a first treatment episode increased over time.

CONCLUSION

Despite the prevalence of antidepressant use increased over time, incidence did not, which is most likely explained by a longer treatment duration and recurrent episodes.

Off-label utilization of antidepressants

While antidepressant prescription rules are established for approved indications by large-scale studies, off-label utilization naturally often lacks the validation by large scientific databases, and is at its best based on expert consensus. The aim of the present survey was to study the prescription habits of hospital psychiatrists with regard to antidepressants, comparing patients treated for depressions and anxiety disorder with patients receiving off-label antidepressant treatment.

METHODS

Data on drug use for this study were based on 6 reference days from April 1999 to November 2001 in the 98-bed psychiatric hospital of the University of Lausanne, Switzerland. The drug prescriptions of 174 patients were assessed.

RESULTS

Whereas the diagnosis did not influence the choice between newer or older antidepressants, patients presenting an anxiety disorder were 4.5 times more likely (p<0.05) and patients with other diagnoses 8 times more likely (p<0.001) to receive an antipsychotic comedication compared to patients whose primary diagnosis was a depressive disorder. Also, patients receiving concomitantly a nonbenzodiazepine hypnotic were less likely to be prescribed an older antidepressant (p<0.05). While patients with anxiety disorder and those with major depression received their antidepressants at comparable doses, patients with an off-label indication were treated preferentially with lower doses.

CONCLUSIONS

The results of this survey suggest, that the prescribing hospital psychiatrists developed preferences with regard to the choice of the antidepressant class, which they then used for both registered and off-label indications. They then seemed to adapt the dose and the comedication according to the diagnosis, confirming the initial study hypothesis.

Pharmacogenetics of drug-induced arrhythmias: a feasibility study using spontaneous adverse drug reactions reporting data

PURPOSE

The bottleneck in pharmacogenetic research on rare adverse drug reactions (ADR) is retrieval of patients. Spontaneous reports of ADRs may form a useful source of patients. We investigated the feasibility of a pharmacogenetic study, in which cases were selected from the database of a spontaneous reporting system for ADRs, using drug-induced arrhythmias as an example.

METHODS

Reports of drug-induced arrhythmias to proarrhythmic drugs were selected from the database of the Netherlands Pharmacovigilance Centre (1996-2003). Information on the patient's general practitioner (GP) was obtained from the original report, or from another health care provider who reported the event. GPs were contacted and asked to recruit the patient as well as two age, gender and drug matched controls. Patients were asked to fill a questionnaire and provide a buccal swab DNA sample through the mail. DNA samples were screened for 10 missense mutations in 5 genes associated with the congenital long-QT (LQT) syndrome (KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2).

RESULTS

We identified 45 eligible cases, 29 GPs could be contacted of which seven were willing to participate. Four cases and five matched controls could be included in the study, giving an overall participation rate of 9% (4/45). The main reason for GPs not being willing to participate was lack of time. Variants were identified in KCNH2, SCN5A and KCNE1.

CONCLUSIONS

Spontaneous reporting systems for ADRs may be used for pharmacogenetic research. The methods described, however, need to be improved to increase participation and international collaboration may be required.

Antidepressants: general practitioners' opinions and clinical practice

OBJECTIVE

To describe and compare general practitioners' (GPs) opinions on antidepressant drugs and their prescriptions to depressed patients.

METHOD

Between November 2000 and July 2001 a representative sample of French GPs was asked their opinion of the 15 most prescribed antidepressants, and then to describe the treatments of the current depressive episode of four depressive patients each, their changes and the reasons thereof.

RESULTS

One hundred and eighty-one GPs and 778 patients participated. The best-ranked antidepressants by the GPs were paroxetine, fluoxetine, sertraline and clomipramine for efficacy, and paroxetine, tianeptine, sertraline and fluoxetine for tolerability. In patients, the drugs most often prescribed were fluoxetine, paroxetine, and sertraline. Those least often stopped for intolerance were moclobemide (0%), dosulepine (0%), venlafaxine (4.5%) and citalopram (5.0%), and maprotiline (0%), citalopram (1.7%) and venlafaxine (2.3%) for lack of efficacy. The best predictor for prescription of antidepressants was the GPs' overall ranking, itself depending on opinions of the tolerability and efficacy of the drug. However, opinions of tolerability and efficacy were not related to the rates of treatment discontinuation for intolerability or inefficacy.

CONCLUSION

Prescriber opinion does not seem related to actual product performance.

Potential bias in pharmacoepidemiological studies due to the length of the drug free period: a study on antidepressant drug use in adults in the Netherlands

PURPOSE

The aim of this study was to evaluate the effect of the length of the drug free period on incidence measurements as well as on cohort characteristics in users of antidepressants.

METHODS

The study population consisted of patients aged 18 years or older who filled a prescription for an antidepressant drug in the Netherlands, between October 2001 and September 2002. One-year incidence of antidepressant drug use was estimated using drug free periods varying in length from 1 month to 9 years. In addition, we evaluated what effect the drug free period has on cohort characteristics by comparing a cohort of first time antidepressant drug users defined using a 9-year drug free period with cohorts using 6, 12 and 24 months drug free period.

RESULTS

When using a 6-month drug free period the measured incidence was about 32 per 1,000 individuals (95%CI: 31.3, 32.6) while the measured incidence was 27.5 (95%CI: 26.9, 28.1), 23.5 (95%CI: 22.9, 24.0) and 17.2 (95%CI: 16.7, 17.7) per 1,000 individuals when using a 12-month, 24 month respectively a 9-year drug free period. Furthermore, the prevalence of characteristics in inception cohort studies changes when using different drug free periods.

CONCLUSION

Altering the drug free period from a short to a longer one results in decreased incidence. Furthermore, for inception cohorts where first time drug use is an inclusion criterion the drug free period can influence the prevalence of cohort characteristics and for short drug free periods give biased estimates.

Antidepressants: psychiatrists' opinions and clinical practice

OBJECTIVE

To describe and compare psychiatrists' opinion on antidepressant drugs and their prescriptions to depressed patients.

METHOD

Between January and September 1999 a representative sample of French psychiatrists was asked their opinion of the 15 most prescribed antidepressants, and then to describe the treatments of the current depressive episode of four depressive patients each, their changes and the reason thereof.

RESULTS

A total of 232 psychiatrists and 935 patients participated. The best ranked antidepressants were clomipramine, paroxetine and amitriptyline for efficacy, tianeptine, paroxetine and citalopram for tolerability. In patients, the most often prescribed were paroxetine, fluoxetine and venlafaxine. Those least often stopped for intolerance were tianeptine (2.9%), citalopram (5.2%), venlafaxine (3.3%) and amitriptyline (5.7%) for lack of efficacy. There was no difference in stopping rates for inefficacy of tricyclics and serotonin-selective agents.

CONCLUSION

The best predictors for the prescribed antidepressants were the psychiatrists' overall rankings and opinions of the tolerability of the drug.

Prescribing patterns of tricyclic and selective serotonin reuptake inhibitor antidepressants among a sample of adolescents and young adults

PURPOSE

There are few studies that document antidepressant prescribing in young patients. Although tricyclic antidepressants (TCAs) are considered equal in efficacy to selective serotonin reuptake inhibitors (SSRIs), the latter have an improved side effect profile. The aim of this study was to investigate the prescribing patterns of TCAs and SSRIs among adolescents and young adults, with reference to prescribing frequency, cost and dose.

METHOD

A retrospective drug utilization study was conducted over a 14-month period, from January 2000 to February 2001.

RESULTS

There were 166 antidepressants prescribed to 98 adolescents and young adults. TCAs were prescribed more frequently than SSRIs, with amitryptiline and fluoxetine being the two most frequently prescribed antidepressants. Fluoxetine accounted for a higher ratio of cost to prescribing frequency than amitryptiline. Amitryptiline was issued in small quantities of tablets, resulting in a low average calculated prescribed daily dose (PDD). Duration of treatment was not considered optimal for SSRIs or TCAs.

CONCLUSION

This study elicits prescribing patterns that contribute to the relative scarcity of data on antidepressant drugs for young patients.