Patient compliance with enteric-coated weekly fluoxetine during continuation treatment of major depressive disorder.
BACKGROUND
A once-weekly enteric-coated formulation of fluoxetine represents a new, effective option for the long-term treatment of clinically diagnosed depression. This study assessed compliance with the new once-weekly fluoxetine as compared with once-daily fluoxetine treatment.


METHODS
Adult patients from the United Kingdom who had responded to fluoxetine treatment for a current episode of depression (DSM-IV criteria) were monitored for compliance with daily and weekly dose administration of fluoxetine. The study consisted of 2 study phases. Study phase I was a baseline assessment of 20 mg of fluoxetine daily dosing for 4 weeks (N = 117). The second phase of the study consisted of randomly assigning patients to either once-weekly (90 mg/wk) or once-daily (20 mg/day) fluoxetine for 3 months (weekly, N = 56; daily, N = 53). Compliance with the dosing regimen was measured using an electronic Drug Exposure Monitor (eDEM, AARDEX Ltd., Zug, Switzerland).


RESULTS
For those patients randomly assigned to weekly fluoxetine, compliance was 85.4% during study period I while on treatment with daily fluoxetine and then 87.5% while on treatment with weekly fluoxetine. This difference was not significant. For once-daily dosing, however, compliance declined from 87.3% during period I to 79.4% during period II (p < .001). After adjusting for compliance during study period I, weekly compliance during study period II was 87.8% and daily compliance was 79.0%, a statistically significant difference (p = .006).


CONCLUSIONS
Compliance with once-weekly fluoxetine was better than that with once-daily fluoxetine. Compliance decreased over time when patients remained on daily dosing; however, when patients switched from daily dosing to weekly dosing, compliance did not decrease. The results of this study allay concerns about inferior compliance with a once-weekly regimen compared with the conventional once-daily regimen.
de Klerk
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AARDEX Ltd, Maastricht, The Netherlands. erik@aardex.net
D000328:Adult; D003866:Depressive Disorder / Q000188:drug therapy* / Q000517:prevention & control / Q000523:psychology; D004334:Drug Administration Schedule; D016903:Drug Monitoring / Q000295:instrumentation / Q000706:statistics & numerical data; D005260:Female; D005473:Fluoxetine / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010349:Patient Compliance / Q000706:statistics & numerical data; D010352:Patient Dropouts / Q000706:statistics & numerical data; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D055502:Secondary Prevention; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D013608:Tablets, Enteric-Coated
D005473:Fluoxetine; D017367:Selective Serotonin Reuptake Inhibitors; D013608:Tablets, Enteric-Coated