Desvenlafaxine Dosing in Elderly Patients with Impaired Renal Function
For elderly patients with impaired renal function, the recommended starting dose of desvenlafaxine is 25 mg once daily, with a maximum dose of 50 mg every other day for those with severe renal impairment (creatinine clearance 15-29 mL/min). 1
Dosing Recommendations Based on Renal Function
Normal to Mild Renal Impairment
- Normal renal function: Standard dose of 50 mg once daily
- Mild renal impairment: Standard dose of 50 mg once daily
Moderate to Severe Renal Impairment
Moderate renal impairment (CrCl 30-50 mL/min):
- Maximum recommended dose: 50 mg once daily
- Consider starting at 25 mg once daily in elderly patients
Severe renal impairment (CrCl 15-29 mL/min):
- Maximum recommended dose: 25 mg once daily or 50 mg every other day
- Start with 25 mg once daily in elderly patients
End-stage renal disease (CrCl <15 mL/min):
- Maximum recommended dose: 25 mg once daily or 50 mg every other day
- Supplemental doses should not be given after dialysis 1
Special Considerations for Elderly Patients
The FDA label specifically notes that for elderly patients, reduced renal clearance of desvenlafaxine should be considered when determining dose 1. This is particularly important because:
- Elderly patients often have decreased renal function affecting medication clearance
- Elderly patients may be more susceptible to adverse effects
- There is a higher incidence of systolic orthostatic hypotension in patients ≥65 years of age 1
Administration Guidelines
- Desvenlafaxine should be taken at approximately the same time each day
- Tablets must be swallowed whole with fluid and not divided, crushed, chewed, or dissolved
- Can be taken with or without food 1
Monitoring Recommendations
When treating elderly patients with impaired renal function with desvenlafaxine, monitor for:
- Orthostatic hypotension (particularly in patients ≥65 years)
- Hyponatremia (elderly patients may be at greater risk)
- Serotonin syndrome (particularly if combined with other serotonergic medications)
- Discontinuation symptoms if dose is missed or medication is stopped
Discontinuation
When discontinuing desvenlafaxine in elderly patients with renal impairment:
- Gradually reduce the dosage rather than stopping abruptly
- The 25 mg dose is specifically intended for gradual reduction when discontinuing treatment 1
- Monitor closely for discontinuation symptoms
Important Cautions
- Desvenlafaxine has linear pharmacokinetics with a half-life of approximately 10 hours 2
- Clearance rates are reduced in the elderly and those with renal dysfunction 2
- No additional therapeutic benefits have been demonstrated at doses higher than 50 mg/day 3, 4
- The risk of adverse effects increases at higher doses
By following these specific dosing guidelines for elderly patients with impaired renal function, clinicians can optimize the safety and efficacy of desvenlafaxine treatment while minimizing the risk of adverse effects.