Pediatric Pharmacotherapy

Fluoxetine and its successors (Table 1) differ from the heterocyclic antidepressants in that they inhibit serotonin reuptake, with little or no effect on other receptor sites. As a result of this specificity, these agents are referred to as selective serotonin reuptake inhibitors (SSRIs). Their clinical efficacy is believed to be the result of an initial increase in serotonin concentrations (inhibition of reuptake) in the synaptic cleft followed by desensitization of serotonin autoreceptors and increasing serotonin release. The latter effect is likely the most significant in treating symptoms of depression. Similar to the heterocyclic antidepressants, the full effect of SSRI therapy does not occur until two to three weeks after the initiation of treatment.