Paroxetine drops versus paroxetine tablets: evaluation of compliance in a six-month study.

AIMS: Literature data show that one third of patients discontinue antidepressant therapy within the first month of treatment. The aim of this study was to evaluate whether paroxetine liquid solution 10 mg/ml may influence adherence inpatients receiving long-term treatment. METHODS: 71 subjects affected by mood disorders or panic disorder were monitored for six months. The study sample was divided into two groups: controls (n=33) maintained their own therapy with paroxetine tablets; 38 patients maintained the same dosage of paroxetine, but shifted to liquid formulation 10 mg/ml. Compliance and general wellness were evaluated with the Medication Adherence Rating Scale (MARS) and the World Health Organization Quality of Life questionnaire (WhoQol). Data were analyzed using analysis of variance (ANOVA) and multivariate analysis of covariance (MANCOVA). RESULTS: Significant differences were found in MARS scores: patients on oral solution 10 mg/ml showed an improvement of compliance month by month. In addition, age, formulation and quality of life had a significant impacton patient compliance. Significant correlations were found between MARS and quality of life. A specific paroxetine formulation could be a variable able to influence adherence to psychopharmacological treatment. The same consideration can be made for quality of life, sex and age that showed a trend towards improved adherence when compared with controls. Inparticular, the WhoQol subscale analysis of delta scores showed a significant difference in self-perception of quality of life inpatients treated with paroxetine either in tablet or drop formulation. DISCUSSION: Formulation in drops 10 mg/ml is equally effective to tablets, but it may allow patients having a higher cognition and control on drug assumption.