Last reviewed 2026-04-20 · How we verify

Effexor (Venlafaxine Hydrochloride)

Potentiates serotonin and norepinephrine in CNS through reuptake inhibition.

Venlafaxine hydrochloride extended-release capsules are an SNRI indicated for treating major depressive disorder, generalized anxiety disorder, social anxiety disorder, and panic disorder in adults. The drug demonstrates moderate absolute bioavailability (45%) with linear kinetics and is extensively metabolized hepatically via CYP2D6 to active metabolite ODV. Critical safety concerns include contraindication with MAOIs due to serotonin syndrome risk and potential bleeding interactions with anticoagulants. Extended-release formulation provides slower absorption with lower peak concentrations compared to immediate-release, improving tolerability while maintaining therapeutic efficacy.

At a glance

Mechanism of action

Venlafaxine hydrochloride is a serotonin-norepinephrine reuptake inhibitor (SNRI) that works by inhibiting the reuptake of serotonin and norepinephrine in the central nervous system. This mechanism increases the availability of these neurotransmitters in synaptic spaces, which is thought to underlie its therapeutic effects in treating mood and anxiety disorders. The exact mechanism of action in treating major depressive disorder, generalized anxiety disorder, social anxiety disorder, and panic disorder remains incompletely understood, but is believed to be related to this potentiation of serotonergic and noradrenergic neurotransmission.

Approved indications

• Generalized anxiety disorder
• Major depressive disorder
• Panic disorder
• Social phobia

Boxed warnings

• WARNING: SUICIDAL THOUGHTS AND BEHAVIORS Antidepressants increased the risk of suicidal thoughts and behavior in pediatric and young adult patients in short-term studies. Closely monitor all antidepressant-treated patients for clinical worsening, and emergence of suicidal thoughts and behaviors [see Warnings and Precautions (5.1 )] . Venlafaxine hydrochloride extended-release capsules are not approved for use in pediatric patients [see Use in Specific Populations (8.4) ] . WARNING: SUICIDAL THOUGHTS AND BEHAVIORS See full prescribing information for complete boxed warning. • Increased risk of suicidal thoughts and behavior in pediatric patients and young adults taking antidepressants. Closely monitor all antidepressant-treated patients for clinical worsening and emergence of suicidal thoughts and behaviors (5.1) . • Venlafaxine hydrochloride extended-release capsules are not approved for use in pediatric patients (8.4) .

Common side effects

• Nausea
• Somnolence
• Headache
• Insomnia
• Constipation
• Dizziness
• Malaise
• Diarrhoea
• Palpitations
• Decreased appetite
• Hepatic function abnormal
• Fatigue

Drug interactions

• Monoamine Oxidase Inhibitors (MAOIs), including linezolid and intravenous methylene blue
• Other serotonergic drugs (SNRIs, SSRIs, triptans, tricyclic antidepressants, opioids, lithium, buspirone, amphetamines, tryptophan, St. John's Wort)
• Antiplatelet or anticoagulant drugs

Key clinical trials

• Venlafaxine as Adjunct Therapy in Rheumatoid Arthritis (PHASE2)
• The Analgesic Efficacy and Safety of Venlafaxine for Prevention of Postherpetic Neuralgia in Patients With Acute Herpes Zoster (NA)
• A Study Following Women in Menopause Treated With a Non-hormonal Therapy for Hot Flashes and Night Sweats
• Pharmacokinetics and Safety of Commonly Used Drugs in Lactating Women and Breastfed Infants
• The Efficacy and Safety of Short Term S-ketamine Infusion as an Adjunctive Therapy in Patients With Fibromyalgia (NA)
• The Analgesic Efficacy and Safety of Desvenlafaxine in Patients With Herpes Zoster (NA)
• Intensified Pharmacological Treatment for Schizophrenia, Major Depressive Disorder and Bipolar Depression After a First-time Treatment Failure (PHASE3)
• Desvenlafaxine for Preventive Treatment of Frequent Episodic Tension-type Headache (NA)

Primary sources

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Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Effexor CI brief — competitive landscape report
• Effexor updates RSS · CI watch RSS
• Pfizer portfolio CI