Venlafaxine
Administration
- Type: SNRI
- Dosage Forms:
- Routes of Administration: Oral
- Common Trade Names: Effexor
Adult Dosing
- Extended release: 37.5-225mg PO daily
- Immediate release: 75-375mg PO daily in 2-3 divided doses
Pediatric Dosing
Safety/efficacy not established
Special Populations
- Pregnancy Rating: C
- Lactation risk: Infant risk cannot be ruled out
- Renal dosing: decrease dose by 25-50%
- Hepatic dosing: decrease dose by 25-50%
Contraindications
- Allergy to class/drug
- MAOI use concomitantly or within past 14 days
Toxicity[1]
- Sodium channel blocking properties, similar to TCA toxicity and should be treated similarly:
- Sodium bicarbonate for QRS prolongation
- Benzodiazepines for seizures
- QTc prolongation
Adverse Reactions
Serious
- Seizure
- Neuroleptic malignant syndrome, serotonin syndrome
- GI bleed
- Hepatitis
- Hyponatremia
- Exacerbation of depression, suicidality, mania
Common
- Constipation, nausea, xerostomia, anorexia, weight loss
- Dizziness, insomnia, somnolence, dream disorder, tremor, anxiety, blurred vision
- Sweating
- Hypertension
- Sexual dysfunction
Pharmacology
- Half-life: 5-11h
- Metabolism: Hepatic, CYP2D6
- Excretion: Mostly renal
Mechanism of Action
- Inhibits serotonin, norepinephrine and dopamine reuptake
Comments
See Also
References
- ↑ Whyte IM et al. Relative toxicity of venlafaxine and selective serotonin reuptake inhibitors in overdose compared to tricyclic antidepressants. QJM: An International Journal of Medicine, Volume 96, Issue 5, 1 May 2003, Pages 369–374.