Optimisation of pharmacotherapy for depression during pregnancy. Pilot study for evaluation of existing paroxetine therapy

Objective: The aim of this retrospective pilot study was to investigate whether other modern antidepressants than fluoxetine show low steady state plasma concentrations during pregnancy. The second aim of this study was to investigate the relationship between possibly lower blood levels and the score on the Montgomery-Asberg Depression Rating Scale (MADRS). Design and methods: In Bronovo hospital 12 mothers taking paroxetine were enrolled in the study. Trough plasma samples, collected 3 times during pregnancy and 1 time postpartum according to the standard Antidepressants and pregnancy in Bronovo hospital, were studied. The efficacy of the paroxetine treatment was evaluated with scores on the MADRS during pregnancy and postpartum. Results: Paroxetine concentrations were lower in the third trimester than in the first trimester (p = 0,011) and higher postpartum than in the third trimester (p = 0,012). MADRS scores were higher in the third trimester than in the first trimester (p = 0,041) and lower postpartum than in the third trimester (p = 0,017). There was no significant relationship between lower paroxetine concentrations and lower scores on the depression severity scale. Conclusion: Paroxetine concentrations decrease during pregnancy. No significant relationship was found between lower paroxetine concentrations and lower scores on the depression severity scale. Clinicians should be alert to the possibility that depression in pregnancy is under-treated. A multidisciplinary standard for hospital settings to deal with the use of antidepressants during pregnancy is important. Therapeutic drug monitoring can be useful in this respect