23 - Terms used to describe therapeutic effects of

Terms used to describe therapeutic effects of antidepressants

© SPMM Course compared to buspirone but achieves higher brain concentration in the brain. Buspirone acts as a partial agonist on serotonin 5-HT1A receptors – presynaptic agonism leads to inhibition of release of serotonin, with consequent antianxiety effects. Postsynaptic agonism leads to antidepressant activity. St John’s wort: It acts via multiple monoamine reuptake inhibition. It is a CYP inducer and can interact with warfarin, OCPs and antiepileptics, decreasing their efficacy. Terms used to describe therapeutic effects of antidepressants

Mirtazapine reaches peak plasma concentrations within 2 hours; it binds to plasma proteins (85%) and has a bioavailability is approximately 50%, owing to extant first-pass metabolism. It follows first-order linear elimination kinetics over a dose range of 15 to 80mg. The elimination t ½ ranges from 20 to 40 hours. Metabolism is mediated by the CYP2D6 and CYP3A4; thus paroxetine and fluoxetine, which inhibit the CYP system, can increase plasma concentrations of mirtazapine by 1/5th to 1/3rd but usually there are no clinical consequences. Carbamazepine causes a 60% decrease in plasma concentrations. Mirtazapine has no inhibitory effects on CYP isoenzymes. Agomelatine undergoes extensive first-pass metabolism with a low bioavailability. It is extensively protein bound (95%) and has a half-life of 2.3 hours. It is mostly metabolized by CYP1A2 (90%) and CYP2C9 (10%).

•minimal or <25% decrease in baseline severity of sx non-response non-response •25-50% reduction in baseline severity (sx still evident) partial response partial response •>50% reduction, but still some sx evident partial remission partial remission

•no sx; returning to normal function (<6months from last episode) remission remission •return to fully sx state when in remission relapse relapse

•extended remission sustained for longer than 6-12 months recovery recovery

•onset of a new episode of depression when in recovery recurrence recurrence