Spontaneous lapses in dosing during chronic treatment with selective serotonin reuptake inhibitors

BACKGROUND: In previous research, lapses in dosing of paroxetine or sertraline were associated with significantly more discontinuation symptoms and deterioration of depressive symptomatology compared with fluoxetine. AIMS: To evaluate dosing lapses in patients chronically treated with selective serotonin reuptake inhibitors (SSRIs) in uncontrolled circumstances. METHOD: In a prospective observational study we evaluated compliance data in chronic users of SSRIs using electronic drug exposure monitors. RESULTS: During a 3-month follow-up we found that 50/69 (72.5%) patients missed at least one dosing day and 20/69 (29.0%) missed two or more consecutive days. CONCLUSIONS: About 30% of patients treated with short-acting SSRIs had dosing lapses of 2 or more days, which, as described in prior studies, is long enough to result in clinically relevant deterioration of mental status.