A medication used to treat depression.


A selective serotonin and norepinephrine reuptake inhibitor (SNRI) used for the treatment of major depression.


Venlafaxine (Effexor) is an antidepressant within the serotonin-norepinephrine reuptake inhibitor (SNRI) class of medications. It exerts its effects primarily by blocking the transporters involved in the reuptake of the neurotransmitters serotonin and norepinephrine, therefore leaving more active neurotransmitter in the synapse. Venlafaxine is officially approved for use in the management of major depressive disorder (MDD), generalized anxiety disorder (GAD), social anxiety disorder, and panic disorder. As of 2014, Canadian clinical practice guidelines recommend venlafaxine as a first-line option for treatment of generalized anxiety, social anxiety, panic disorder, major depressive disorder (MDD), and consider it a second-line option for management of obsessive-compulsive disorder (OCD) [9,Read more



Venlafaxine is indicated in the management of major depressive disorder (MDD), generalized anxiety disorder (GAD), social anxiety disorder (social phobia), and panic disorder with or without agoraphobia. Venlafaxine is also used off-label for prophylaxis of migraine headaches [ Read more


The mechanism of venlafaxine's (and its metabolite, O-desmethylvenlafaxine (ODV)) antidepressant effect is believed to be due to their potentiation of neurotransmitter activity in the central nervous system through the inhibition of the reuptake of serotonin and norepinephrine from within the synaps... Read more

Mechanism of action

The exact mechanism of action of venlafaxine is unknown, but appears to be associated with the potentiation of neurotransmitter activity in the CNS. Venlafaxine and its active metabolite, O-desmethylvenlafaxine (ODV), inhibit the reuptake of both serotonin and norepinephrine with a potency greater f... Read more


Venlafaxine is well absorbed, with at least 92% of a single dose absorbed on the basis of mass balance studies [FDA Label]. Food does not affect the absorption of venlafaxine or its subsequent metabolism into ODV. Bioavailability is 45% following oral administration.
Time to steady state = 3 days.

Protein binding

The degree of binding of venlafaxine to human plasma is 27% ± 2% at concentrations ranging from 2.5 to 2215 ng/mL. The degree of ODV binding to human plasma is 30% ± 12% at concentrations ranging from 100 to 500 ng/mL. Protein-binding-induced drug interactions with venlafaxine are not expected.

Volume of distribution

7.5 ± 3.7 L/kg [venlafaxine]5.7 ± 1.8 L/kg [O-desmethylvenlafaxine(active metabolite)]


Steady state plasma clearance, venlafaxine = 1.3 ± 0.6 L/h/kg;Steady state plasma clearance, ODV = 0.4 ± 0.2 L/h/kg.

Half life

5 hours

Route of elimination

Renal elimination of venlafaxine and its metabolites is the primary route of excretion. Approximately 87% of a venlafaxine dose is recovered in the urine within 48 hours as either unchanged venlafaxine (5%), unconjugated ODV (29%), conjugated ODV (26%), or other minor inactive metabolites (27%).


Overdose of venlafaxine is typically associated with mild symptoms. However, severe toxicity is reported with the most common symptoms being CNS depression, serotonin toxicity, seizure, or cardiac conduction abnormalities. Venlafaxine's toxicity appears to be higher than other SSRIs, with a fatal to... Read more

Adverse Effects


  • Hypersensitivity:
    • true
  • Regions: US
  • Time Period: The use of MAOIs within 7 days of stopping treatment with venlafaxine, or the use of venlafaxine within 14 days of stopping and MAOI is contraindicated.
  • Regions: US
  • With Categories:
      • Name: Monoamine Oxidase Inhibitors
      • Drugbank Id: DBCAT001004
      • Mesh Id: D008996

Food Interactions

  • Avoid alcohol. Prescribing information recommends the avoidance of alcohol during therapy.
  • Avoid St. John's Wort. Co-administration of St. John's Wort may lead to additive serotonergic activity and an increased risk of serotonin syndrome.
  • Take with food. Co-administration with food helps to alleviate/mitigate GI upset.


Type in a drug name to check for interaction with Venlafaxine
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  • Paracetamol(acetaminophen)
  • Paxil(paroxetine)
  • Pamelor(nortriptyline)
  • Panadol(acetaminophen)
  • Patanol(olopatadine ophthalmic)
  • Pataday(olopatadine ophthalmic)
  • Parnate(tranylcypromine)
  • Pazeo(olopatadine ophthalmic)
Venlafaxine may increase the antiplatelet activities of (R)-warfarin.
Venlafaxine may increase the antiplatelet activities of (S)-Warfarin.
The metabolism of Venlafaxine can be decreased when combined with 1-(2-Phenylethyl)-4-phenyl-4-acetoxypiperidine.
The risk or severity of hypoglycemia can be increased when Venlafaxine is combined with 2,4-thiazolidinedione.
The risk or severity of serotonin syndrome can be increased when Venlafaxine is combined with 2,5-Dimethoxy-4-ethylamphetamine.
The risk or severity of adverse effects can be increased when Venlafaxine is combined with 2,5-Dimethoxy-4-ethylthioamphetamine.
The risk or severity of adverse effects can be increased when Venlafaxine is combined with 4-Bromo-2,5-dimethoxyamphetamine.
Venlafaxine may increase the tachycardic activities of 4-Bromo-2,5-dimethoxyphenethylamine.
Venlafaxine may increase the antiplatelet activities of 4-hydroxycoumarin.
The metabolism of 4-Methoxyamphetamine can be decreased when combined with Venlafaxine.
The metabolism of 5-methoxy-N,N-dimethyltryptamine can be decreased when combined with Venlafaxine.
The risk or severity of adverse effects can be increased when Venlafaxine is combined with 7-Nitroindazole.
7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline may increase the serotonergic activities of Venlafaxine.
Venlafaxine may decrease the excretion rate of Abacavir which could result in a higher serum level.
The metabolism of Venlafaxine can be increased when combined with Abatacept.
Venlafaxine may increase the antiplatelet activities of Abciximab.
Venlafaxine may increase the tachycardic activities of Abediterol.
Venlafaxine may increase the excretion rate of Abemaciclib which could result in a lower serum level and potentially a reduction in efficacy.
The risk or severity of QTc prolongation can be increased when Venlafaxine is combined with Abexinostat.
The metabolism of Venlafaxine can be decreased when combined with Abiraterone.
18 References
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  11. 11 . Gallagher HC, Gallagher RM, Butler M, Buggy DJ, Henman MC: Venlafaxine for neuropathic pain in adults. Cochrane Database Syst Rev. 2015 Aug 23;(8):CD011091. doi: 10.1002/14651858.CD011091.pub2.PubMed: 26298465
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  13. 13 . Handley AP, Williams M: The efficacy and tolerability of SSRI/SNRIs in the treatment of vasomotor symptoms in menopausal women: a systematic review. J Am Assoc Nurse Pract. 2015 Jan;27(1):54-61. doi: 10.1002/2327-6924.12137. Epub 2014 Jun 19.PubMed: 24944075
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  17. 17 . FDA Approved Drug Products: Effexor XR® extended-release capsules Link
  18. 18 . FDA Approved Drug Products: Venlafaxine oral tablets Link