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Understanding Antidepressant Medications (cont.)

Venlafaxine (Effexor)

  • Venlafaxine (Effexor) may alter the blood levels and/or risk of toxicity of the following drugs:
    • clozapine (Clozaril)
    • desipramine (Norpramin)
    • haloperidol (Haldol)
    • indinavir (Crixivan)
    • SSRIs, sibutramine (Meridia), sumatriptan (Imitrex), trazodone (Desyrel), and St. John's wort (These medications may increase the risk for serotonin syndrome - symptoms include hypertension, fever, muscle tremor, or confusion.)
    • warfarin (Coumadin)
  • The following drugs may increase venlafaxine blood levels or toxicity:
    • cimetidine (Tagamet)
    • MAOIs
    • SSRIs, nefazodone (Serzone), St. John's wort, and venlafaxine (These medications may increase the risk for serotonin syndrome - symptoms include hypertension, fever, muscle tremor, or confusion.)

Atypical Antidepressants Side Effects

This is NOT a complete list of side effects reported with atypical antidepressants. The doctor, health care provider, or pharmacist can discuss a more complete list of side effects.

  • Manic episodes in persons with bipolar disorder (If not combined with a mood-stabilizing drug, atypical antidepressants may induce manic episodes in individuals with bipolar disorder.)
  • Seizures (Atypical antidepressants may lower the threshold for seizures; that is, seizures may occur more easily. Caution is advised for individuals prone to seizures or those who have a history of seizures.)
  • Drowsiness (Caution is advised when operating machinery, driving, or performing other tasks that require alertness.)
  • bupropion (Wellbutrin, Wellbutrin SR, Wellbutrin XL, Zyban)
    • Contains the same active ingredient found in Zyban, which is used as an aid in smoking cessation treatment (Do not use bupropion with Zyban or other medications containing bupropion.)
    • More likely to cause seizures than other antidepressants, especially with doses above 450 mg/day (Seizures are also more likely in patients who have bulimia or anorexia nervosa and are treated with bupropion.)
    • Caution in narrow-angle glaucoma
    • Caution in slow gastric emptying (often present in diabetes)
  • maprotiline (Ludiomil), mirtazapine (Remeron)
    • May increase appetite and cause weight gain
    • May decrease white blood cell count (The doctor will monitor this throughout the therapy.)
    • May cause urinary retention, blurred vision, heart rhythm abnormalities, dizziness, or constipation
    • Caution in heart disease and abnormal heart rhythms
  • nefazodone (Serzone)
    • May cause liver impairment (Contact the doctor immediately if dark urine, anorexia, stomach or abdominal pain, or yellowing of the skin or eyes occurs.)
    • Caution in heart disease and abnormal heart rhythms
    • Lightheadedness or fainting when standing up from a sitting or lying position (Stand up gradually from lying down or sitting positions.)
  • trazodone (Desyrel)
    • Caution in heart disease and abnormal heart rhythms
  • venlafaxine (Effexor)
    • May cause sustained increases in blood pressure
    • May cause weight loss
    • May cause anxiety and insomnia
    • Decreased dose required for individuals with kidney or severe liver impairment

Medically reviewed by Marina Katz, MD; American Board of Psychiatry & Neurology


Selective serotonin reuptake inhibitors: Pharmacology, administration, and side effects

Atypical antidepressants: Pharmacology, administration, and side effects

Last Editorial Review: 12/10/2015

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