How to take desvenlafaxine (Pristiq)?

How to Take Desvenlafaxine (Pristiq)

Desvenlafaxine should be taken at a dose of 50 mg once daily, with or without food, at approximately the same time each day. 1

Dosing Instructions

• The recommended starting and therapeutic dose is 50 mg once daily, as clinical studies have shown no additional benefit at higher doses while adverse reactions increase 1, 2
• Tablets must be swallowed whole with fluid and should not be divided, crushed, chewed, or dissolved 1
• Desvenlafaxine can be taken with or without food as its bioavailability (80%) is not affected by food intake 2
• For consistent blood levels, take at approximately the same time each day 1
• Steady-state plasma concentrations are achieved within 4-5 days of once-daily dosing 3

Special Populations

• Renal impairment: 1

  • Moderate impairment (CrCl 30-50 mL/min): Maximum 50 mg daily
  • Severe impairment (CrCl 15-29 mL/min): 25 mg daily or 50 mg every other day
  • End-stage renal disease: 25 mg daily or 50 mg every other day
  • Supplemental doses should not be given after dialysis

• Hepatic impairment: 1

  • Moderate to severe impairment (Child-Pugh score 7-15): 50 mg daily
  • Dose escalation above 100 mg daily is not recommended

Duration of Treatment

• Major depressive disorder typically requires several months or longer of sustained pharmacologic therapy 1
• Patients should be periodically reassessed to determine the need for continued treatment 1

Discontinuation

• Do not stop desvenlafaxine abruptly as discontinuation symptoms may occur 1
• Always gradually reduce the dosage when discontinuing treatment 1
• The 25 mg daily dose is specifically intended for gradual dose reduction when discontinuing treatment 1
• Individualize the taper schedule based on dose, duration of treatment, and patient response 4

Switching Medications

• When switching from other antidepressants to desvenlafaxine, tapering of the initial antidepressant may be necessary to minimize discontinuation symptoms 1
• When switching from MAOIs to desvenlafaxine, allow at least 14 days after stopping the MAOI before starting desvenlafaxine 1
• When switching from desvenlafaxine to an MAOI, allow at least 7 days after stopping desvenlafaxine before starting the MAOI 1

Common Side Effects to Monitor

• Most common side effects include nausea, dizziness, insomnia, and somnolence 5
• Side effects are generally similar to those seen with venlafaxine 5
• If bleeding events occur (such as petechiae), medical evaluation is needed as desvenlafaxine may be associated with bleeding risk 4

Advantages of Desvenlafaxine

• No titration required - can start with therapeutic dose of 50 mg 2
• Minimal inhibitory effects on CYP2D6, suggesting lower risk of drug-drug interactions compared to some other antidepressants 2
• Low protein binding (30%) and independence from drug concentration may reduce potential for certain drug interactions 2