Ireven (Venlafaxine)

Venlafaxine is used to treat several mood and anxiety disorders by modulating serotonin and norepinephrine pathways.

• Major depressive disorder: reduces depressive symptoms and improves overall mood.
• Generalized anxiety disorder: lessens excessive worry and associated physical tension.
• Social anxiety disorder: decreases fear of social situations and improves functioning.
• Panic disorder: lowers frequency and severity of panic attacks.

• Venlafaxine blocks the reuptake of serotonin and norepinephrine at presynaptic neuronal terminals by inhibiting the serotonin transporter (SERT) and the norepinephrine transporter (NET). This increases extracellular concentrations of both neurotransmitters, enhancing neurotransmission in brain regions that regulate mood and anxiety. The dual action differentiates it from selective serotonin reuptake inhibitors and contributes to its therapeutic efficacy.

Venlafaxine may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Nausea
• Headache
• Dry mouth
• Insomnia
• Dizziness
• Sweating

Serious or Rare Side Effects

• Increased blood pressure
• Serotonin syndrome
• Severe liver injury
• Suicidal thoughts or behavior
• Allergic reactions including anaphylaxis
• Abnormal heart rhythm

When prescribing venlafaxine, clinicians should consider several safety precautions.

• Monitor blood pressure: check regularly as the drug can raise systolic and diastolic values.
• Assess for suicidal ideation: especially during treatment initiation and dose changes.
• Evaluate hepatic function: dose adjustment may be needed in severe liver impairment.
• Review concomitant serotonergic agents: to minimize risk of serotonin syndrome.
• Consider pregnancy status: use only if benefits outweigh potential risks.
• Store at ambient temperature: keep below 25 °C in the original container, protect from moisture and light.

Venlafaxine can interact with other medicines, altering its effectiveness or safety profile.

Major Interactions (Avoid)

• Monoamine oxidase inhibitors (MAOIs): risk of severe hypertension and serotonin syndrome.
• Other serotonergic agents (e.g., SSRIs, SNRIs, triptans): heightened serotonin syndrome risk.
• Linezolid or methylene blue: potent serotonergic activity.
• Certain antiarrhythmic drugs: may affect cardiac conduction.
• High‑dose NSAIDs: increased bleeding risk.

Moderate Interactions (Monitor Closely)

• CYP2D6 inhibitors (e.g., fluoxetine, paroxetine): may raise venlafaxine levels.
• CYP3A4 inhibitors (e.g., ketoconazole): can increase exposure.
• Antihypertensive agents: venlafaxine may blunt blood‑pressure‑lowering effects.
• Alcohol: may enhance central nervous system depression.
• Herbal supplements such as St. John’s wort: potential additive serotonergic activity.