DESVENLAFAXINE
Clinical safety rating: caution
MAOIs can cause serotonin syndrome Can increase blood pressure and cause withdrawal symptoms upon discontinuation.
Selective serotonin and norepinephrine reuptake inhibitor (SNRI) that potentiates the activity of serotonin and norepinephrine in the central nervous system by blocking their reuptake at presynaptic neurons.
| Metabolism | Primarily metabolized by conjugation (UGT) and to a lesser extent by CYP3A4 to N,O-didesvenlafaxine; minimal CYP2D6 involvement. |
| Excretion | Renal: approximately 45% as unchanged desvenlafaxine and 23% as glucuronide conjugate. Fecal: minimal (<1%). Biliary: negligible. |
| Half-life | Terminal elimination half-life is approximately 11 hours (range 8.5-13 hours). This supports once-daily dosing without need for extended-release formulation. |
| Protein binding | Low protein binding: 30% bound to plasma proteins (primarily albumin and alpha-1-acid glycoprotein). |
| Volume of Distribution | Apparent volume of distribution (Vd/F) is approximately 3.4 L/kg, indicating extensive extravascular distribution. |
| Bioavailability | Oral: Absolute bioavailability is about 80%. |
| Onset of Action | Oral: Clinical improvement in depression and anxiety may be observed within 1-2 weeks, but full therapeutic effect may require 4-8 weeks. |
| Duration of Action | Oral: Duration of action is approximately 24 hours due to once-daily dosing. Steady-state achieved within 4-5 days. Clinical effects persist for several weeks after discontinuation. |
50 mg orally once daily, with or without food. May increase to 100 mg/day if tolerated and needed. Maximum dose 100 mg/day.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | GFR 30-49 mL/min: 50 mg every 48 hours. GFR 15-29 mL/min: 50 mg every 72 hours. ESRD or on dialysis: 50 mg every 72 hours; not removed by dialysis. |
| Liver impairment | Child-Pugh Class A or B: no adjustment. Child-Pugh Class C: maximum dose 50 mg every 48 hours. |
| Pediatric use | Not approved for use in pediatric patients. Safety and effectiveness not established. |
| Geriatric use | No specific dose adjustment; consider starting at 25 mg daily due to potential for reduced renal function and increased sensitivity. Maximum dose 100 mg daily. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
MAOIs can cause serotonin syndrome Can increase blood pressure and cause withdrawal symptoms upon discontinuation.
| FDA category | Animal |
| Breastfeeding | Desvenlafaxine is excreted into human breast milk with an M/P ratio of approximately 0.9. Relative infant dose is estimated at 5-8% of maternal weight-adjusted dose. Case reports indicate low levels in infant plasma with no adverse effects; however, long-term neurodevelopmental effects unknown. Caution is advised; alternative agents with more breastfeeding safety data may be preferred. |
| Teratogenic Risk |
■ FDA Black Box Warning
Antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults in short-term studies. Monitor closely for clinical worsening, suicidality, or unusual changes in behavior.
| Common Effects | anxiety disorders |
| Serious Effects |
["Concomitant use with MAOIs or within 14 days of MAOI discontinuation (risk of serotonin syndrome).","Uncontrolled narrow-angle glaucoma (due to mydriatic effect).","Hypersensitivity to desvenlafaxine or any component of the formulation."]
| Precautions | ["Serotonin syndrome: Risk with co-administration of serotonergic drugs.","Elevation of blood pressure: Dose-dependent; monitor blood pressure regularly.","Activation of mania/hypomania: Screen for bipolar disorder.","Angle-closure glaucoma: May cause mydriasis; risk in patients with narrow angles.","Sexual dysfunction: May cause ejaculatory delay and impotence.","Discontinuation syndrome: Taper dose gradually to avoid withdrawal symptoms.","Hyponatremia: Risk particularly in elderly or volume-depleted patients."] |
Loading safety data…
| Desvenlafaxine is classified as FDA Pregnancy Category C. Limited human data; animal studies have shown fetal harm at doses exceeding maximum recommended human dose. First trimester: No clear evidence of major malformations, but increased risk of spontaneous abortion reported. Second trimester: no specific risk identified. Third trimester: neonatal adaptation syndrome including respiratory distress, feeding difficulties, jitteriness, cyanosis, and apnea. Use only if potential benefit justifies risk. |
| Fetal Monitoring | Monitor for signs of neonatal adaptation syndrome at delivery. In pregnancy, monitor maternal blood pressure and heart rate regularly due to desvenlafaxine's potential to increase blood pressure. Assess for serotonin syndrome, especially when co-administered with other serotonergic drugs. Consider fetal ultrasound for growth and well-being if used long-term. |
| Fertility Effects | In animal studies, desvenlafaxine caused reduced fertility and impaired spermatogenesis at high doses. Human data are lacking; no clinical studies on fertility effects in women. Potential for reversible sexual dysfunction in men and women, which may indirectly affect fertility. Use with caution in patients attempting conception. |