Relationship between parameters of serotonin transport and antidepressant plasma levels or therapeutic response in depressive patients treated with paroxetine and amitriptyline

Abstract

In a double-blind clinical study, antidepressant plasma levels, parameters of platelet serotonin (5-HT) transport (Km, Vmax and basal platelet 5-HT content) and therapeutic response were measured in depressive patients treated with either paroxetine (30 mg/day) or amitriptyline (150 mg/day) for 6 weeks. No correlation could be found between paroxetine plasma levels and therapeutic outcome after 2, 4 and 6 weeks of treatment. In contrast to the amitriptyline group, a marked increase in Km from baseline to week 2 was determined in paroxetine-treated patients, with Km increase being correlated with paroxetine plasma levels at week 2. However, no significant relationship could be found between 5-HT transport parameters and any of the outcome measures in either treatment group.

Progressive resistance to a selective serotonin reuptake inhibitor but not to cognitive therapy in the treatment of major depression.

“…Blood level assays of paroxetine would have provided a more trustworthy index of whether a given patient was taking any paroxetine at all, but paroxetine blood levels provide a poor index of the extent to which a patient has taken the prescribed amount of medicine because of very high variance in plasma concentrations in patients taking the same dose of paroxetine (e.g., Normann, Horn, Hummel, Grunze, & Walden, 2004). Furthermore, reliable relationships between plasma levels and clinical outcome have not been obtained in studies of paroxetine therapy (e.g., Kuhs, Schlake, Rolf, & Rudolf, 1992; Normann et al, 2004; Tasker, Kaye, Zussman, & Link, 1989). Judgments of compliance with CT were provided by subjective ratings that combined the therapist's estimates of the patient's use of CT techniques, homework completion, and session attendance.…”

Pharmacokinetics of paroxetine, a selective serotonin reuptake inhibitor, in Grey parrots (Psittacus erithacus erithacus): influence of pharmaceutical formulation and length of dosing

“…In addition, it should be noted that in human adjustments in the dosage regimen for paroxetine are initially guided by its clinical effect, especially as no clear correlation has been found between plasma paroxetine concentrations and clinical efficacy or tolerability (Tasker et al. , 1989; Kuhs et al. , 1992).…”

Paroxetin: Pharmakokinetik und Pharmakodynamik

“…In bisher vorliegenden Untersuchungen fand sich keine Beziehung zwischen Plasmaspiegeln im Steadystate und therapeutischen Effekten oder Nebenwirkungen (37). Es bedarf allerdings weitergehender Studien, um dies abzusichern.…”