Venlafaxine-induced psychotic symptoms

Abstract

Venlafaxine, an antidepressant belongs to Serotonin Norepinephrine Reuptake Inhibitors (SNRI), blocks the synaptic reuptake of serotonin in lower doses and also blocks reuptake of norepinephrine in higher doses. In addition it also blocks dopamine reuptake in still higher doses. This last mechanism of action is found to cause psychotic symptoms. Very few cases are reported with this adverse effect of venlafaxine. Here is a case report where a 32 year-old male with social phobia developed delusions of persecution on two occasions when he was put on venlafaxine 150 mg/day, which responded to withdrawal of venlafaxine and a short course of antipsychotics. The delusions never reappeared when he was maintained on escitalopram.

Antidepressant-induced akathisia-related homicides associated with diminishing mutations in metabolizing genes of the CYP450 family

“…There were no interacting drugs in her regimen, however, her genotype for 2D6 (*2/*4) places her in the intermediate metabolizer category, for which there is evidence of at least twofold increases in serum-venlafaxine levels in both single dose and steady-state studies 75–77. Moreover, case reports have documented serious venlafaxine-related adverse events, which are either suspected or confirmed to have resulted from above-therapeutic-range serum-venlafaxine levels; the events ranged from psychosis78,79 to hallucination, psychomotor agitation, and delirium 80–82…”

Body Dysmorphic Disorder Incidentally Treated With Bupropion

“…It has been shown that, for inhibition of ALDH, disulfiram needs to be converted to active metabolites by hepatic P-450 enzymes, including CYP3A4/5. 10 The resulting effect is norepinephrine depletion and dopamine accumulation. 7 A previously suggested synergistic inhibition of ALDH by metronidazole and disulfiram is similarly questionable because metronidazole does not block ALDH.…”

A Case of High-Dose Venlafaxine-Related Psychosis

“…9 One of the metabolites of disulfiram is diethyldithiocarbamate, which inhibits dopamine-A-hydroxylase (DBH), an enzyme that converts dopamine to norepinephrine. 10 The resulting effect is norepinephrine depletion and dopamine accumulation. 11 Metronidazole, which effectively passes the blood-brain barrier, 12 was demonstrated in vitro to inhibit bovine monoamine oxidase (MAO), a prime dopamine catabolizing enzyme.…”