What it's for (Indications)
- Venlafaxine, a serotonin-norepinephrine reuptake inhibitor (SNRI), is primarily indicated for the treatment of Major Depressive Disorder (MDD) in adults.
- Its efficacy in alleviating the core symptoms of depression, including persistent low mood, anhedonia, changes in appetite or sleep patterns, fatigue, and difficulty concentrating, has been well-established through extensive clinical trials.
- Beyond MDD, venlafaxine is also approved for the management of several anxiety disorders.
- These include Generalized Anxiety Disorder (GAD), characterized by chronic and excessive worry and tension, and Social Anxiety Disorder (SAD), also known as social phobia, involving intense fear in social situations.
- Furthermore, it is indicated for the treatment of Panic Disorder (PD), a condition marked by recurrent, unexpected panic attacks and anticipatory anxiety.
- The decision to initiate venlafaxine for any of these conditions should be made by a qualified healthcare professional following a thorough diagnostic assessment, considering the patient's overall clinical presentation and medical history.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | Venlafaxine extended-release tablets should be administered as a single daily dose with food, either in the morning or evening, at approximately the same time each day. Tablets must be swallowed whole and not divided, crushed, chewed, or placed in water. For Major Depressive Disorder, the recommended starting dose is 75 mg/day (in some patients, 37.5 mg/day for 4 to 7 days). Doses can be increased by 75 mg/day increments at intervals of 4 days or longer, up to a maximum of 225 mg/day. For Social Anxiety Disorder, the recommended starting dose is 75 mg/day, with no additional benefit shown at higher doses, making 75 mg/day the maximum dose for this indication. Discontinuation of treatment should be gradual and individualized as necessary, typically over at least 1 to 2 weeks for patients on high doses for more than 6 weeks. |
Safety & Warnings
Common Side Effects
- Abnormal dreams, abnormal ejaculation, abnormal vision, agitation, akathisia, anorexia, anxiety, asthenia, chills, confusion, depersonalization, dizziness, dry mouth, dyspnea, fatigue, GI upset, headache, hypertension, hypertonia, hyponatremia, impotence, insomnia, libido decreased, menstrual disorders, nausea, nervousness, orgasmic dysfunction, palpitations, paresthesia, pruritis, raised cholesterol, rash, sexual dysfunction, SIADH, somnolence, sweating, tachycardia, tinnitus, tremor, urinary disorders, vasodilatation, weight change, yawning.
- Rarely, neuroleptic malignant syndrome and gastrointestinal bleeding may occur.
Serious Warnings
- Black Box Warning: WARNING: SUICIDALITY AND ANTIDEPRESSANT DRUGS Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of Major Depressive Disorder (MDD) and other psychiatric disorders. Anyone considering the use of venlafaxine extended-release tablets or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressant use in patients over 24; there was a reduction in risk with antidepressant use in patients 65 and older.
- Venlafaxine should be used cautiously in patients with moderate to severe kidney or liver impairment, liver cirrhosis, heart disease, history of epilepsy, drug abuse, and mania.
- Careful consideration is required for patients with bleeding tendencies, hypovolemia, raised intraocular pressure (IOP), risk of narrow-angle glaucoma, micturition disorders, and in the elderly.
- Blood pressure and serum cholesterol should be monitored during therapy.
- Patients on long-term therapy require re-evaluation.
- Patients should be advised to report the development of a rash.
- Dose increases may be detrimental in patients who develop akathisia.
- Use this drug cautiously in patients with risk factors for QT prolongation or serious arrhythmia.
- Withdrawal should be gradual and individualized, typically over at least 1 to 2 weeks, especially if high doses have been used for more than 6 weeks.
- Patients at risk for suicidal behavior must be monitored.
How it Works (Mechanism of Action)
The mechanism of the antidepressant action of venlafaxine in humans is believed to be associated with its potentiation of neurotransmitter activity in the CNS. Preclinical studies have shown that venlafaxine and its active metabolite, O-desmethylvenlafaxine (ODV), are potent inhibitors of neuronal serotonin and norepinephrine reuptake and weak inhibitors of dopamine reuptake.