DESVENLAFAXINE SUCCINATE
Clinical safety rating: caution
MAOIs can cause serotonin syndrome Can increase blood pressure and cause withdrawal symptoms upon discontinuation.
Desvenlafaxine is a serotonin and norepinephrine reuptake inhibitor (SNRI). It binds to the serotonin transporter (SERT) and norepinephrine transporter (NET), preventing reuptake of these neurotransmitters and increasing their concentrations in the synaptic cleft.
| Metabolism | Primarily metabolized by conjugation (UGT isoforms) and to a lesser extent by CYP3A4. Desvenlafaxine is also a substrate of CYP3A4, but metabolism is not significantly affected by CYP2D6 polymorphisms. |
| Excretion | Renal: 45% as unchanged desvenlafaxine and 19% as glucuronide conjugate; biliary/fecal: minimal (<5%). Total renal excretion accounts for approximately 64% of the dose. |
| Half-life | Terminal elimination half-life is approximately 11 hours in healthy adults, supporting once-daily dosing. Steady-state is achieved within 4-5 days. |
| Protein binding | 30% bound to plasma proteins, primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Volume of distribution is approximately 3.4 L/kg (range 1.5-5.5 L/kg), indicating extensive extravascular distribution. |
| Bioavailability | Oral bioavailability is approximately 80% (range 70-90%) after a 100 mg dose, with a high-fat meal decreasing Cmax by about 18% but not affecting AUC. |
| Onset of Action | Oral: Clinical improvement in major depressive disorder may be observed within 1-2 weeks, but full therapeutic effect typically requires 4-8 weeks. |
| Duration of Action | Duration of action is approximately 24 hours with once-daily dosing, allowing sustained symptom control. Tapering is recommended to avoid discontinuation syndrome. |
| Molecular Weight | 399.48 |
Oral: 50 mg once daily; may increase to 100 mg once daily based on tolerability. Maximum 100 mg/day.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | CrCl 30-50 mL/min: 50 mg once daily; CrCl 15-29 mL/min: 50 mg every other day; CrCl <15 mL/min or ESRD: not recommended. |
| Liver impairment | Child-Pugh Class A or B: no adjustment needed; Class C: not recommended due to lack of data. |
| Pediatric use | Approved for ages ≥12 years: 50 mg once daily; may increase to 100 mg once daily. Not approved for <12 years. |
| Geriatric use | Start at 50 mg once daily; caution with renal impairment. No specific dose adjustment based solely on age. |
| 1st trimester | Data are limited; risk of spontaneous abortion may be increased. Use only if potential benefit justifies risk. |
| 2nd trimester | May cause poor neonatal adaptation syndrome after prolonged exposure. Use cautiously. |
| 3rd trimester | Risk of persistent pulmonary hypertension of the newborn (PPHN) and neonatal withdrawal syndrome. Consider tapering before delivery. |
Clinical note
MAOIs can cause serotonin syndrome Can increase blood pressure and cause withdrawal symptoms upon discontinuation.
| FDA category | Animal |
| Placental transfer | Crosses the placenta in vitro and in vivo; likely to reach fetal circulation. |
| Breastfeeding |
■ 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 discontinuationUncontrolled narrow-angle glaucomaKnown hypersensitivity to desvenlafaxine or venlafaxine
| Precautions | Serotonin syndrome or neuroleptic malignant syndrome-like reactions, Elevated blood pressure (dose-related), Increased risk of bleeding events (especially with NSAIDs/aspirin), Activation of mania/hypomania, Angle-closure glaucoma (mydriatic effect), Sexual dysfunction, Discontinuation syndrome (taper dose gradually) |
| Food/Dietary |
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| Desvenlafaxine is excreted into human milk at low levels. Monitor infant for agitation, irritability, and poor feeding. Benefits of breastfeeding should be weighed against potential risks. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | Pregnancy Category C. First trimester: Case reports suggest a small increased risk of cardiovascular malformations, particularly ventricular septal defects, with exposure to desvenlafaxine. Second and third trimesters: Risk of persistent pulmonary hypertension of the newborn (PPHN), poor neonatal adaptation syndrome including respiratory distress, feeding difficulties, jitteriness, hypotonia, and seizures. Late third trimester exposure may increase risk of postpartum hemorrhage. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate regularly. Assess for serotonin syndrome symptoms, especially if co-administered with other serotonergic drugs. Fetal monitoring: Ultrasound to assess fetal growth and development during second and third trimesters. Neonatal monitoring: Observe for signs of poor neonatal adaptation syndrome for 48-72 hours after delivery. |
| Fertility Effects | In animal studies, no adverse effects on fertility or reproductive performance at doses up to 2 times the maximum recommended human dose. Human data limited; may cause reversible menstrual irregularities and sexual dysfunction, which could theoretically impact fertility. |
| Take with or without food. Avoid alcohol. Grapefruit juice does not significantly alter desvenlafaxine pharmacokinetics; no specific dietary restrictions required. |
| Clinical Pearls | Desvenlafaxine succinate is a serotonin-norepinephrine reuptake inhibitor (SNRI) and the major active metabolite of venlafaxine. It exhibits linear pharmacokinetics with minimal CYP2D6 involvement, making dose adjustments unnecessary for CYP2D6 poor metabolizers. It has a low potential for drug-drug interactions relative to venlafaxine. Abrupt discontinuation may precipitate withdrawal symptoms including dizziness, nausea, headache, and paresthesias; taper gradually over 2-4 weeks. Monitor blood pressure regularly due to dose-dependent increases. Onset of therapeutic effect typically occurs within 2-4 weeks. Avoid use within 14 days of MAOI therapy due to risk of serotonin syndrome. |
| Patient Advice | Take exactly as prescribed; do not stop suddenly without consulting your doctor as withdrawal symptoms may occur. · It may take several weeks to feel the full benefit; do not increase dose without medical advice. · Report any severe headache, chest pain, confusion, or vision changes as these may indicate elevated blood pressure. · Avoid alcohol as it can increase dizziness and drowsiness. · Notify your doctor if you become pregnant, plan to become pregnant, or are breastfeeding. · Do not take with MAO inhibitors or within 14 days of stopping them. · If you miss a dose, take it as soon as you remember unless it is close to the next dose; do not double the dose. · Store at room temperature away from moisture and heat. |