II. Mechanism

  1. Desvenlafaxine is an active metabolite of Effexor XR

III. Efficacy

  1. May be less effective than Venlafaxine XR (Effexor XR)
    1. Venlafaxine XR is generic as of 2010 and is preferred
  2. No added benefit over Effexor XR and with possibly more adverse effects
    1. Easier to dose (only one dose) but as noted above, this is less effective than Effexor
    2. Touted to be better tolerated than Effexor, but studies do not bear this out

IV. Safety

  1. Unknown safety in Lactation
  2. Unknown pregnancy category
    1. Postpartum Hemorrhage (second and third trimester use)
    2. Neonatal Distress (second and third trimester use)

V. Preparations

  1. Pristiq (Desvenlafaxine Succinate)
  2. Desvenlafaxine ER (extended-release base preparation)
    1. Equivalent to Pristiq (but requires specific instructions to pharmacist to allow substitution)
    2. As with Pristiq, no significant benefit when compared with Venlafaxine XR (which is generic and much less expensive)

VI. Dosing

  1. Dose: 50 mg orally daily
    1. No evidence that doses over 50 mg offer added benefit
    2. Decrease dose to 25 mg in stage 4 Chronic Kidney Disease (eGFR <30 ml/min)
  2. Tapering (do not cut tablet)
    1. Week 1: Skip one dose
    2. Week 2: Skip two doses
    3. Week 3: Skip three doses
    4. Week 4: Stop medication

VII. Adverse Effects

  1. See Venlafaxine
  2. Antidepressant Withdrawal
  3. Empty ghost capsule in stool (typical finding)

VIII. Drug Interactions

X. References

  1. (2023) Med Lett Drugs Ther 62(1592): 25-32
  2. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 38-9
  3. Hamilton (2020) Tarascon Pocket Pharmacopoeia
  4. (2013) Presc Lett 20(7):40
  5. (2008) Presc Lett 15(5): 28
  6. (2008) Ann Pharmacother 42:1439 [PubMed]

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Related Studies

Cost: Medications

desvenlafaxine (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
DESVENLAFAXINE ER 100 MG TAB Generic $3.88 each
DESVENLAFAXINE SUCCNT ER 100 MG Generic $0.52 each
pristiq (on 1/1/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
PRISTIQ ER 100 MG TABLET Generic $0.52 each
PRISTIQ ER 25 MG TABLET Generic $0.52 each
PRISTIQ ER 50 MG TABLET Generic $0.48 each