What is the recommended dosing for duloxetine (Serotonin-Norepinephrine Reuptake Inhibitor - SNRI)?

Duloxetine Dosing Guidelines

The recommended initial dose of duloxetine is 30 mg once daily for 1 week before increasing to the target dose of 60 mg once daily for most indications, with dose adjustments based on specific conditions and patient factors. 1, 2

Standard Dosing Protocol

• Start with 30 mg once daily for 1 week to improve initial tolerability and reduce the risk of nausea 1, 3
• Increase to 60 mg once daily after 1 week, which is the target dose for most indications 2
• Duloxetine should be administered orally and swallowed whole; do not chew, crush, or open the capsule 2
• May be taken with or without food 2

Indication-Specific Dosing

• Major Depressive Disorder (MDD):

  • Start with 30 mg once daily for 1 week, then increase to 60 mg once daily 2
  • While 120 mg/day has shown effectiveness, there is no evidence that doses greater than 60 mg/day confer additional benefits 2

• Generalized Anxiety Disorder (GAD):

  • Adults <65 years: 60 mg once daily (may start at 30 mg for 1 week) 2
  • Geriatric patients: 30 mg once daily for 2 weeks before increasing to 60 mg/day 2
  • Pediatric patients (7-17 years): 30 mg once daily for 2 weeks before considering increase to 60 mg once daily 2

• Diabetic Peripheral Neuropathic Pain:

  • 60 mg once daily 2, 4
  • No evidence that higher doses confer additional benefits 2
  • For patients with renal impairment, consider lower starting dose with gradual titration 2, 5

• Fibromyalgia:

  • Start at 30 mg once daily for 1 week, then increase to 60 mg once daily 2
  • No evidence that doses greater than 60 mg/day provide additional benefit 2, 4

• Chronic Musculoskeletal Pain (osteoarthritis, low back pain):

  • 60 mg once daily 1, 4

Special Populations

• Elderly patients: Start with lower doses (30 mg once daily) and titrate more slowly 1, 2
• Renal impairment: Consider lower starting dose and gradual titration 5, 2
• Hepatic impairment: Avoid use in patients with any hepatic insufficiency 2

Dose Adjustments and Titration

• If increasing beyond 60 mg daily is necessary, increase in increments of 30 mg once daily 2
• Maximum studied dose is 120 mg per day 2, 6
• When discontinuing after more than 3 weeks of treatment, taper over at least 2-4 weeks to minimize discontinuation symptoms 1, 7

Administration Pearls

• If a dose is missed, take it as soon as remembered; if close to next dose, skip the missed dose 2
• Do not take two doses at the same time 2
• Most adverse events occur during the first week of treatment and are typically mild to moderate in severity 3, 6
• Common adverse effects include nausea, dry mouth, headache, constipation, dizziness, and fatigue 7, 3

Clinical Considerations

• Duloxetine does not typically produce clinically important electrocardiographic or blood pressure changes 1
• Routine liver enzyme monitoring is generally unnecessary 1
• Avoid concomitant use with potent CYP1A2 inhibitors 7
• Contraindicated with MAOIs due to risk of serotonin syndrome 5, 7

By following these dosing guidelines, clinicians can optimize the therapeutic benefits of duloxetine while minimizing potential adverse effects.