Milven (Venlafaxine)

Venlafaxine is an SNRI used to treat several mood and anxiety disorders.

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

• Venlafaxine inhibits the reuptake of serotonin and norepinephrine by blocking their respective transporters (SERT and NET) in central nervous system synapses, leading to increased extracellular concentrations of these neurotransmitters. The enhanced serotonergic and noradrenergic signaling modulates mood, anxiety and pain pathways, contributing to its therapeutic effects. These actions are dose‑dependent, with higher doses producing greater norepinephrine reuptake inhibition and modest effects on dopamine at very high doses.

Venlafaxine may be associated with a range of adverse reactions, varying in frequency and severity.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Dry mouth: reduced salivation.
• Dizziness: transient light‑headedness.
• Insomnia: difficulty falling or staying asleep.
• Sweating: increased perspiration.
• Constipation: reduced bowel movements.

Serious or Rare Side Effects

• Hypertension: elevated blood pressure requiring monitoring.
• Serotonin syndrome: potentially life‑threatening condition with agitation, hyperthermia, and neuromuscular abnormalities.
• Suicidal thoughts: emergence of suicidal ideation, especially in early treatment.
• Severe liver injury: rare hepatotoxicity.
• Allergic reactions: rash, angioedema, or anaphylaxis.
• Cardiac arrhythmia: abnormal heart rhythm.

When prescribing Venlafaxine, clinicians should consider several safety considerations.

• Cardiovascular assessment: monitor blood pressure and heart rate, especially at higher doses.
• Psychiatric monitoring: observe for worsening depression or emergence of suicidal thoughts.
• Drug discontinuation: taper gradually to avoid withdrawal symptoms.
• Pregnancy and lactation: use only if benefits outweigh potential risks, as safety data are limited.
• Drug interactions: review concomitant serotonergic agents to reduce risk of serotonin syndrome.
• Store at ambient temperature: keep below 25 °C in the original container, protect from moisture and light.

Venlafaxine can interact with several medicines, affecting its efficacy or safety.

Major Interactions (Avoid)

• MAO inhibitors: risk of severe hypertension and serotonin syndrome.
• Other serotonergic agents (e.g., SSRIs, tramadol): increased serotonin syndrome risk.
• CYP2D6 inhibitors (e.g., quinidine, paroxetine): can raise venlafaxine plasma levels.
• NSAIDs or anticoagulants: heightened bleeding risk.
• Thioridazine: may cause QT prolongation.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., carbamazepine, rifampin): may reduce venlafaxine exposure.
• Antihypertensives: additive blood pressure lowering effect.
• Alcohol: may enhance CNS depression.
• Diuretics: potential for electrolyte imbalance.
• Lithium: monitor for additive neuropsychiatric effects.