What is the recommended starting dose of Pristiq (desvenlafaxine) for anxiety?

Recommended Starting Dose of Pristiq for Anxiety

The recommended starting dose of Pristiq (desvenlafaxine) for anxiety is 50 mg once daily, which is both the initial and therapeutic dose. 1

Dosing Guidelines

Pristiq should be administered according to the following protocol:

• Start with 50 mg once daily
• Take with or without food
• Administer at approximately the same time each day
• Swallow tablets whole with fluid; do not divide, crush, chew, or dissolve

Key Considerations

• Clinical studies have evaluated doses ranging from 10 mg to 400 mg per day, but no additional benefit was demonstrated at doses greater than 50 mg daily 1
• Higher doses are associated with increased adverse reactions and discontinuations 1
• The 50 mg dose has shown efficacy in treating anxiety symptoms in patients with depression 2

Special Populations

Renal Impairment

• Moderate impairment (CrCl 30-50 mL/min): Maximum 50 mg/day
• Severe impairment (CrCl 15-29 mL/min): Maximum 25 mg/day or 50 mg every other day
• ESRD (CrCl <15 mL/min): Maximum 25 mg/day or 50 mg every other day
• Do not give supplemental doses after dialysis 1

Hepatic Impairment

• Moderate to severe impairment (Child-Pugh score 7-15): 50 mg/day
• Dose escalation above 100 mg/day not recommended 1

Efficacy in Anxiety

Desvenlafaxine 50 mg/day has demonstrated significant efficacy in treating anxiety symptoms:

• In a pooled analysis of seven randomized, placebo-controlled studies, desvenlafaxine 50 mg/day significantly improved depressive symptoms compared with placebo in patients with clinically relevant anxiety symptoms 2
• Response and remission rates were significantly higher with desvenlafaxine compared with placebo in patients with anxiety 2

Side Effects and Monitoring

Common adverse effects include:

• Insomnia
• Somnolence
• Dizziness
• Nausea 3

Switching and Discontinuation

When Switching to Pristiq

• Discontinuation symptoms may occur when switching from other antidepressants
• Taper the initial antidepressant to minimize discontinuation symptoms 1

When Discontinuing Pristiq

• Gradually reduce the dosage rather than stopping abruptly
• The 25 mg/day dose is intended for gradual reduction when discontinuing treatment 1
• Allow at least 7 days after stopping desvenlafaxine before starting an MAOI 1

Clinical Pearls

• Desvenlafaxine is the active metabolite of venlafaxine and has a similar efficacy profile 3
• Desvenlafaxine has decreased CYP2D6 activity compared to venlafaxine, which may be advantageous in patients taking other medications metabolized via this enzymatic pathway 3
• Treatment response is typically seen within 6-7 weeks at the standard dose 4

Remember that while this medication is effective for anxiety, treatment should be periodically reassessed to determine the need for continued therapy 1.