Abstract
Introduction
Based on its primary action of serotonin reuptake inhibition, venlafaxine overdose would be expected to result in serotonergic effects.
Case Report
A 40 year old male ingested venlafaxine without co-ingestants in a suicide attempt. The patient developed refractory ventricular fibrillation and expired approximately 9 hours post-ingestion. ECG monitoring revealed significant QRS and QTC interval prolongation prior to his demise.
Discussion
A literature review of venlafaxine overdose cases and investigation into its mechanism of action was conducted. The potential for sodium channel blockade and implications for therapy are discussed.
Keywords: venlafaxine, fatality, sodium channel poisoning, case report
Full Text
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Footnotes
There was no outside funding of any kind used for this study.
References
- 1.Whyte IM, Dawson AH, Buckley NA. Relative toxicity of venlafaxine and selective serotonin reuptake inhibitors in overdose compared to tricyclic antidepressants. Q J Med. 2003;96:369–374. doi: 10.1093/qjmed/hcg062. [DOI] [PubMed] [Google Scholar]
- 2.Jaffe PD, Batziris HP, van der Hoeven P, DeSilva D, McIntyre IM. A study involving venlafaxine overdoses: comparison of fatal and therapeutic concentrations in postmortem specimens. J Forensic Sci. 1999;44(1):193–196. [PubMed] [Google Scholar]
- 3.Peano C, Leikin JB, Hanashiro PK. Seizures, ventricular tachycardia, and rhabdomyolysis as a result of ingestion of venlafaxine and lamotrigine. Ann Emerg Med. 1997;30(5):704–708. doi: 10.1016/S0196-0644(97)70093-3. [DOI] [PubMed] [Google Scholar]
- 4.Lessard E, Yessine MA, Hamelin BA, O’Hara G, LeBlanc J, Turgeon J. Influence of CYP2D6 activity on the disposition and cardiovascular toxicity of the antidepressant agent venlafaxine in humans. Pharmacogenetics. 1999;9:435–443. doi: 10.1097/00008571-199912000-00003. [DOI] [PubMed] [Google Scholar]
- 5.Bond GR, Steele PE, Uges DR. Massive venlafaxine over-doses resulted in a false positive Abbott AxSYM urine immunoassay for phencyclidine. J Tox Clin Tox. 2003;41(7):999–1002. doi: 10.1081/CLT-120026525. [DOI] [PubMed] [Google Scholar]
- 6.Sena SF, Kazimi S, Wu AH. False-positive phencyclidine immunoassay results caused by venlafaxine and O-desmethylvenlafaxine. Clin Chem. 2002;48(4):676–677. [PubMed] [Google Scholar]
- 7.Tanaka H, Habuchi Y, Nishimura M, Sato N, Watanabe Y. Blockade of Na+ current by promethazine in guinea-pig ventricular myocytes. Br J Pharmacol. 1992;106:900–905. doi: 10.1111/j.1476-5381.1992.tb14432.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Blythe D, Hackett LP. Cardiovascular and neurological toxicity of venlafaxine. Hum Exp Tox. 1999;18:309–313. doi: 10.1191/096032799678840165. [DOI] [PubMed] [Google Scholar]
- 9.Khalifa M, Daleau P, Turgeon J. Mechanism of sodium channel block by venlafaxine in guinea pig ventricular myocytes. J Pharmacol Exp Ther. 1999;29(1):280–284. [PubMed] [Google Scholar]
- 10.Klamerus KJ, Maloney K, Rudolph RL, Sisenwine SF, Jusko WJ, Chiang ST. Introduction of a composite parameter to the pharmacokinetics of venlafaxine and its active O-desmethyl metabolite. J Clin Pharmacol. 1992;32:716–724. doi: 10.1002/j.1552-4604.1992.tb03875.x. [DOI] [PubMed] [Google Scholar]
- 11.Patat A, Troy S, Burke J, Trocherie S, Danjou P, Le Coz F, Allain H, Gandon JM. Absolute bioavailability and electroen-cephalographic effects of conventional and extended-release formulations of venlafaxine in healthy subjects. J Clin Pharmacol. 1998;38:256–267. doi: 10.1002/j.1552-4604.1998.tb04423.x. [DOI] [PubMed] [Google Scholar]
- 12.Kokan L, Dart RC. Life-threatening hypotension from venlafaxine overdose (Abstract) Ann Emerg Med. 1996;27:815–815. [Google Scholar]
- 13.Kolecki P. Isolated venlafaxine-induced serotonin syndrome. J Emerg Med. 1997;15(4):491–493. doi: 10.1016/S0736-4679(97)00078-4. [DOI] [PubMed] [Google Scholar]