This dosage may then be increased by 75 mg every 4 days, but may need to be done slower due to an increased incidence of side effects within the first 1-2 weeks of treatment. No dose reduction is needed in the elderly if no hepatic or renal dysfunction exists. This saturation may 'tie' up the enzyme and contribute to decreased metabolism of other drugs also metabolized by this route. Other drugs that inhibit CYP2D6 such as paroxetine or fluoxetine will increase venlafaxine serum concentrations. Depending on the dose prescribed, these agents are approximately equivalent price.
All antidepressants are equally effective in treating depression.
Studies in TCA-refractory patients need to be performed. Only venlafaxine has been shown to be effective in refractory patients in an open study. Venlafaxine may not be drugs of choice in patients with cardiovascular problems. If no other alternatives exist use venlafaxine cautiously and monitor frequently. More studies need to be conducted to look at the side effect profile for these medications.