Mood disorders:
Indications for: Venlafaxine
Major depressive disorder.
Adult Dosage:
Take with food. ≥18yrs: Initially 75mg/day in 2–3 divided doses; may increase at 4-day intervals in 75mg/day increments to 150mg/day; max 375mg/day, in 3 divided doses. Hepatic impairment: reduce by at least 50%. Renal impairment (mild or moderate): reduce by 25–50%; (severe or undergoing hemodialysis): reduce dose by at least 50%. Withdraw gradually (over 2 weeks).
Children Dosage:
<18yrs: not established.
Venlafaxine Contraindications:
During or within 14 days of MAOIs (see Interactions). Concomitant linezolid or IV methylene blue.
Boxed Warning:
Suicidal thoughts and behaviors.
Venlafaxine Warnings/Precautions:
Increased risk of suicidal thinking and behavior in children, adolescents, and young adults; monitor closely for clinical worsening or unusual changes. Screen for bipolar disorder, mania or hypomania prior to initiation. Monitor for serotonin syndrome; discontinue immediately if occurs. Pre-existing hypertension, cardio- or cerebrovascular disease. Monitor BP before and during treatment; consider dose reduction or discontinuation if elevated BP persists. Heart disease (eg, recent MI, heart failure). Increased risk of bleeding. Angle-closure glaucoma. Avoid in those with untreated anatomically narrow angles. History of mania/hypomania. Seizure disorders. Volume-depleted. Hyponatremia (esp. in elderly). Sexual dysfunction. Renal or hepatic dysfunction. Avoid abrupt disruption; monitor. Reevaluate periodically. Write ℞ for smallest practical amount. Elderly. Labor & delivery. Pregnancy; see full labeling for effects on mother and neonates. Nursing mothers.
See Also:
Venlafaxine Classification:
SNRI.
Venlafaxine Interactions:
See Contraindications. Allow at least 14 days after MAOI discontinuance before starting venlafaxine; allow at least 7 days after venlafaxine discontinuance before starting an MAOI. Increased risk of serotonin syndrome with concomitant other serotonergic drugs (eg, other SNRIs, SSRIs, triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, amphetamines, St. John's Wort) or with drugs that impair serotonin metabolism (eg, MAOIs such as linezolid, IV methylene blue). Avoid alcohol. Potentiated by CYP3A inhibitors; consider reducing dose of venlafaxine. Potentiates CYP2D6 substrates; consider reducing dose of substrate. Concomitant weight loss agents (eg, phentermine), serotonin precursors (tryptophan supplements): not recommended. Caution with other CNS drugs, cimetidine, haloperidol, diuretics, metoprolol, drugs that inhibit CYP2D6, CYP3A4. Increased risk of bleeding with aspirin, NSAIDs, warfarin, or other drugs that affect coagulation; monitor closely. False (+) urine immunoassay screening tests for PCP and amphetamine.
Adverse Reactions:
Nausea, somnolence, dry mouth, sweating, abnormal ejaculation, anorexia, constipation, erectile dysfunction, decreased libido, weight changes, dizziness, insomnia, headache, nervousness, asthenia, vasodilation, abnormal dreams or vision, tremor, yawn, ecchymosis; rare: interstitial lung disease, eosinophilic pneumonia.
Generic Drug Availability:
YES
How Supplied:
XR caps—15, 30, 90; Tabs—Contact supplier
