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Venlafaxine (Effexor)
by Erowid
Listed below are some of the known interactions between Venlafaxine and other chemicals, plants or pharmaceutical medications. This is not a comprehensive list.

Amphetamine Dangerous Single case report of a 32 year old man prescribed both amphetamine (5 mg x 3 per day) and venlafaxine (150 mg x 1 per day) who presented with "marked agitation, anxiety, shivering and tremor". anxiety, shivering, tremor, serotonin syndrome Tentative
Case Report
Prior 2002
Cannabis Life-Threatening Erowid experience report of a man prescribed venlafaxine who experienced tachycardia, arrhythmia, and seizures when he smoked cannabis and then took his normal dose of venlafaxine. Others have reported no such dangerous interaction. tachycardia, arrhythmia, seizure Conflicting
Exp Report
Erowid 2003
Erowid 2004
Erowid 2005
Erowid 2012
Salvia divinorum Life-Threatening Erowid received a report of a man prescribed venlafaxine who experienced two seizure-like episodes on the two occasions that he tried to smoke Salvia divinorum. seizure-like Tentative
Exp Report
Erowid interactions form, Nov 2005, by PR
Lithium Dangerous Single case report of 50 year old woman prescribed both lithium and venlafaxine who was reported to have experienced serotonin syndrome. serotonin syndrome Tentative
Case Report
Mekler 1997
Metoclopramide Dangerous Single case report of 32 year old woman prescribed venlafaxine and administered metoclopramide in a hospital after an injury. She "developed movement disorder and a period of unresponsiveness. After a second dose of metoclopramide, these symptoms recurred and were associated with confusion, agitation, fever, diaphoresis, tachypnea, tachycardia, and hypertension." tachycardia, confusion, hypertension, serotonin syndrome Tentative
Case Report
Fisher 2002
Life-Threatening Several case reports of potentially dangerous interactions. One case report of 44 year-old woman who accidentally ingested phenelzine with venlafaxine and was admitted to an emergency department with lower extremity tremors and rapid respiration where she was diagnosed with serotonin syndrome. Other case reports involve patients who experienced serotonin syndrome while transitioning from phenelzine to venlafaxine. anxiety, tremors, rapid respiration, serotonin syndrome Credible
Case Reports
Weiner LA
Diamond 1998
Propafenone Dangerous Single case report of patient treated for bipolar affective disorder in which venlafaxine given with propafenone caused "markedly increased serum levels of venlafaxine correlating with unexpected psychopathological changes." psychosis Tentative
Case Report
Pfeffer 2001
Tranylcypromine Life-Threatening Single case report of 60 year-old woman who accidentally ingested venlafaxine while on a chronic prescription of tranylcypromine and experienced "altered mental status that progressed to hyperthermia and coma. She recovered quickly and without complications." hyperthermia, coma Tentative
Case Report
Hodgman 1997
Trimipramine Life-Threatening Single case report of 25 year-old woman on 150 mg per day of venlaxine and 100 mg per day of trimipramine hospitalized when seizures occured. Both drugs were discontinued and seizures stopped and did not recur. seizures Tentative
Case Report
Schlienger 2000
If you have a positive or negative drug interaction to report, please let us know! Submit an interaction.
Erowid's interactions information is a summary of data gathered from first hand reports, research, and other resources. This page is intended to collect drug-drug and biology-drug interactions and is not exhaustive: other dangerous or medically important interactions may exist that are not listed here. Drug effects may vary dramatically from one person to another and from one experience to another based on a variety of factors such as body chemistry, age, gender, physical health, dose, and form of material.

  1. Diamond S, Pepper BJ, Diamond ML, Freitag FG, Urban GJ, Erdemoglu AK. Serotonin syndrome induced by transitioning from phenelzine to venlafaxine: four patient reports. Neurology. 1998 Jul;51(1):274-6.
  2. Erowid. Experience 25164: Combo = Seizures. Erowid, 2003.
  3. Erowid. Experience 37376: Tachycardia and Arrythmias. Erowid, 2004.
  4. Erowid. Experience 34429: Effex or Defex. Erowid, 2004.
  5. Erowid. Experience 95587: Nausea at First, Then Fine. Erowid, 2012.
  6. Fisher AA, Davis MW Serotonin syndrome caused by selective serotonin reuptake-inhibitors-metoclopramide interaction. Ann Pharmacother. 2002 Jan;36(1):67-71.
  7. Hodgman MJ, Martin TG, Krenzelok EP. Serotonin syndrome due to venlafaxine and maintenance tranylcypromine therapy. Hum Exp Toxicol. 1997 Jan;16(1):14-7
  8. Mekler G, Woggon B. A case of serotonin syndrome caused by venlafaxine and lithium. Pharmacopsychiatry. 1997 Nov;30(6):272-3.
  9. Pfeffer F, Grube M. An organic psychosis due to a venlafaxine-propafenone interaction. Int J Psychiatry Med. 2001;31(4):427-32.
  10. Prior FH, Isbister GK, Dawson AH, Whyte IM. Serotonin toxicity with therapeutic doses of dexamphetamine and venlafaxine. Med J Australia, 2002; 176(5):240-241
  11. Schlienger RG, Klink MH, Eggenberger C, Drewe J. Seizures associated with therapeutic doses of venlafaxine and trimipramine. Ann Pharmacother. 2000 Dec;34(12):1402-5.
  12. Weiner LA, Smythe M, Cisek J. Serotonin syndrome secondary to phenelzine-venlafaxine interaction. Pharmacotherapy. 1998 Mar-Apr;18(2):399-403.