II. Indications

  1. Major Depression including refractory cases
    1. Considered to be second-line agent
  2. Generalized Anxiety Disorder

III. Mechanism

  1. Similar activity as Tricyclic Antidepressants
  2. Serotonin Norepinephrine Reuptake Inhibitor
    1. Selective Serotonin Reuptake Inhibitor (<150 mg/day)
    2. Norepinephrine Reuptake Inhibitor (>150 mg/day)
  3. Minimally inhibits Dopamine uptake

IV. Pharmacokinetics

  1. Half life: 5 to 11 hours

V. Background

  1. Cost (2013)
    1. Venlafaxine ER (Effexor XR): $20 per month
    2. Desvenlafaxine (Pristiq or the ER base): $140-160 per month

VI. Preparations: Venlafaxine

  1. Venlafaxine regular release (Effexor)
    1. Available as 25, 37.5, 75, 100 mg tablets (scored)
    2. Start: 25 mg PO tid
    3. Effective dose: 150-225 mg per day divided bid to tid
    4. Maximum dose: 375 mg per day
    5. Disadvantages: More adverse effects than Effexor XR
    6. Advantages: May be dosed once daily since metabolites offer similar duration to Effexor XR
  2. Venlafaxine extended release (Effexor XR)
    1. Available as 37.5, 75, 150 mg (capsules)
    2. Start: 37.5 to 75 mg orally daily
    3. Maximum: 225 mg orally daily

VII. Preparations: Desvenlafaxine

  1. Pristiq (Desvenlafaxine Succinate)
    1. Active metabolite of Effexor XR
    2. No added benefit over Effexor XR and with possibly more adverse effects
    3. Reference
      1. (2008) Prescriber's Letter 15(5): 28
  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)
  3. References
    1. (2013) Presc Lett 20(7):40

VIII. Precautions: Prominent Withdrawal symptoms

  1. See also Antidepressant Withdrawal
  2. Dizziness, irritability and Insomnia
  3. Symptoms start 3 days after stopping medication
  4. Effexor taper schedule
    1. Reduce dose 25 mg/day every 5-7 days
    2. Taper to 25-50 mg/day before stopping
  5. Effexor XR taper schedule
    1. Reduce dose 37.5 to 75 mg per day every 7 days
    2. Taper to 37.5 mg/day before stopping

IX. Adverse Effects (higher with regular release Effexor)

  1. Anticholinergic (less than Tricyclic Antidepressants)
    1. Dizziness
    2. Somnolence
    3. Dry Mouth
  2. Nausea or Vomiting
    1. May be severe and limit dosing
    2. Start therapy at 25 mg per day
  3. Increased Blood Pressure
    1. Only seen with total daily doses 300 mg or higher
  4. Less Sexual Dysfunction than Prozac, Zoloft, Paxil
    1. Sexual Dysfunction in 10-15% of cases
    2. Similar to Luvox and Celexa
    3. See Antidepressant Induced Sexual Dysfunction
  5. More stimulating (anxiogenic) than sedating
    1. Agitation or Insomnia may occur
  6. Decreased appetite and Weight loss may occur

X. Drug Interactions

  1. Minimal Cytochrome P450 interactions

XI. References

  1. (1997) Am J Psych 154:1760 [PubMed]
  2. Sundberg (1995) Depression Primary Care, PGM, p. 45-57

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Cost: Medications

venlafaxine (on 8/17/2016 at Medicaid.Gov Survey of pharmacy drug pricing)
VENLAFAXINE HCL 100 MG TABLET Generic $0.34 each
VENLAFAXINE HCL 25 MG TABLET Generic $0.31 each
VENLAFAXINE HCL 37.5 MG TABLET Generic $0.31 each
VENLAFAXINE HCL 50 MG TABLET Generic $0.32 each
VENLAFAXINE HCL 75 MG TABLET Generic $0.29 each
VENLAFAXINE HCL ER 150 MG CAP Generic $0.19 each
VENLAFAXINE HCL ER 150 MG TAB Generic $3.17 each
VENLAFAXINE HCL ER 225 MG TAB Generic $8.10 each
VENLAFAXINE HCL ER 37.5 MG CAP Generic $0.16 each
VENLAFAXINE HCL ER 37.5 MG TAB Generic $2.23 each
VENLAFAXINE HCL ER 75 MG CAP Generic $0.16 each
VENLAFAXINE HCL ER 75 MG TAB Generic $3.85 each
effexor (on 6/1/2016 at Medicaid.Gov Survey of pharmacy drug pricing)
EFFEXOR XR 150 MG CAPSULE Generic $0.19 each
EFFEXOR XR 37.5 MG CAPSULE Generic $0.16 each
EFFEXOR XR 75 MG CAPSULE Generic $0.16 each

Ontology: venlafaxine (C0078569)

Definition (CHV) a kind of depression treatment drug
Definition (NCI_NCI-GLOSS) An antidepressant drug that is being evaluated for the treatment of hot flashes in women who have breast cancer.
Definition (NCI) A synthetic phenethylamine bicyclic derivative with antidepressant activity. Venlafaxine and its active metabolite, O-desmethylvenlafaxine (ODV), are potent inhibitors of neuronal serotonin and norepinephrine reuptake and weak dopamine reuptake inhibitors. This agent may reduce hormone-related vasomotor symptoms. (NCI04)
Definition (CSP) for the treatment of depression; a norepinephrine reuptake inhibitor
Definition (PDQ) A synthetic phenethylamine bicyclic derivative with antidepressant activity. Venlafaxine and its active metabolite, O-desmethylvenlafaxine (ODV), are potent inhibitors of neuronal serotonin and norepinephrine reuptake and weak dopamine reuptake inhibitors. This agent may reduce hormone-related vasomotor symptoms. Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=43238&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=43238&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C1278" NCI Thesaurus)
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH C047426
SnomedCT 108432009, 372490001
LNC LP17950-4, MTHU004272
English venlafaxine, 1-(2-dimethylamino-1-(4-methoxyphenyl)ethyl)cyclohexan-1-ol, venlafaxine [Chemical/Ingredient], VENLAFAXINE, antidepressants venlafaxine, venlafaxine (medication), 1-(2-(dimethylamino)-1-(4-methoxyphenyl)ethyl)cyclohexanol, Venlafaxine, Venlafaxine (product), Venlafaxine (substance), VNF
Spanish venlafaxina (producto), venlafaxina (sustancia), venlafaxina

Ontology: Effexor (C0591437)

Definition (CHV) a kind of depression treatment drug
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH C047426
English effexor, Effexor, Efexor, Trevilor, Vandral, Wyeth brand of venlafaxine hydrochloride, AHP brand of venlafaxine hydrochloride