Overview
Venlafaxine is an SNRI antidepressant used to treat major depressive disorder, generalized anxiety disorder, social anxiety disorder, and panic disorder. It works by increasing serotonin and norepinephrine levels in the brain. The extended-release formulation allows for once-daily dosing.
Mechanism of Action
Venlafaxine and its active metabolite O-desmethylvenlafaxine (ODV) are potent and selective inhibitors of neuronal serotonin and norepinephrine reuptake, with weak dopamine reuptake inhibition. They have minimal affinity for muscarinic, histaminergic, or alpha-adrenergic receptors, reducing anticholinergic and sedative side effects.
Indications
- Major Depressive Disorder (MDD)
- Generalized Anxiety Disorder (GAD)
- Social Anxiety Disorder (SAD)
- Panic Disorder (PD)
Common Doses
- 37.5 mg
- 75 mg
- 150 mg
- 225 mg
Dosage
Typically initiated at 37.5-75 mg once daily (extended-release) and titrated based on response and tolerability. Maximum recommended dose is 225 mg daily. Should be taken with food.
Contraindications
- Hypersensitivity to venlafaxine, desvenlafaxine, or any excipient
- Concomitant use with MAOIs or within 14 days of discontinuing MAOI therapy
Side Effects
- Nausea, headache, insomnia, dry mouth, dizziness
- Somnolence, sweating, nervousness
- Sexual dysfunction
- Increased blood pressure
- Withdrawal symptoms if stopped abruptly
- Serious: serotonin syndrome, suicidal ideation, mania, seizures, bleeding
Interactions
- MAOIs (contraindicated)
- Other serotonergic drugs (SSRIs, SNRIs, triptans, tramadol) increase serotonin syndrome risk
- Drugs affecting CYP2D6 metabolism
- NSAIDs/anticoagulants increase bleeding risk
Counseling Points
- Take with food to reduce nausea
- Do not crush, chew, or open capsules
- Avoid abrupt discontinuation
- Monitor for mood changes, especially in first few months
- Report signs of serotonin syndrome (agitation, fever, sweating)
- Regular blood pressure monitoring recommended
- Avoid alcohol