What is the recommended dose of Tamiflu (oseltamivir) for the treatment of influenza A in an elderly patient with impaired renal function?

From the Guidelines

For elderly patients with impaired renal function who need Tamiflu (oseltamivir) for influenza A treatment, the recommended dose is 75 mg once daily for 5 days for those with a creatinine-clearance rate of 10 to 30 mL/min. This dose adjustment is crucial because oseltamivir is primarily eliminated by the kidneys, and reduced renal function leads to drug accumulation and potential toxicity 1. The treatment should begin as soon as possible within 48 hours of symptom onset for maximum effectiveness. Common side effects include nausea and vomiting, which can be minimized by taking with food. It is also important to monitor for neuropsychiatric events, which occur rarely but more commonly in elderly patients. Ensuring adequate hydration during treatment is also recommended. Some key points to consider when treating elderly patients with impaired renal function include:

• The dose of oseltamivir should be adjusted based on creatinine clearance to avoid drug accumulation and potential toxicity 1.
• For patients with creatinine clearance 10-30 mL/min, the recommended dose is 75 mg once daily for 5 days 1.
• Treatment should begin as soon as possible within 48 hours of symptom onset for maximum effectiveness.
• Common side effects include nausea and vomiting, which can be minimized by taking with food.
• Monitor for neuropsychiatric events, which occur rarely but more commonly in elderly patients.
• Ensure adequate hydration during treatment. The study by Fiore et al. 1 provides the most recent and highest quality evidence for the treatment of influenza A in elderly patients with impaired renal function, and its recommendations should be followed to minimize morbidity, mortality, and improve quality of life.

From the FDA Drug Label

Table 2 Recommended Dosage Modifications for Treatment and Prophylaxis of Influenza in Adults with Renal Impairment or End Stage Renal Disease (ESRD) on Dialysis Renal Impairment (Creatinine Clearance) Recommended Treatment Regimen Mild (>60 to 90 mL/minute) 75 mg twice daily for 5 days Moderate (>30 to 60 mL/minute) 30 mg twice daily for 5 days Severe (>10 to 30 mL/minute) 30 mg once daily for 5 days ESRD Patients on Hemodialysis (≤ 10 mL/minute) 30 mg immediately and then 30 mg after every hemodialysis cycle (treatment duration not to exceed 5 days)

The recommended dose of Tamiflu (oseltamivir) for the treatment of influenza A in an elderly patient with impaired renal function is:

• Mild renal impairment: 75 mg twice daily for 5 days
• Moderate renal impairment: 30 mg twice daily for 5 days
• Severe renal impairment: 30 mg once daily for 5 days
• ESRD on hemodialysis: 30 mg immediately and then 30 mg after every hemodialysis cycle (treatment duration not to exceed 5 days) 2

From the Research

Recommended Dose of Tamiflu (Oseltamivir) for Elderly Patients with Impaired Renal Function

The recommended dose of Tamiflu (oseltamivir) for the treatment of influenza A in an elderly patient with impaired renal function is as follows:

• For patients with severe renal impairment, a dose of 30mg once-daily is recommended 3
• For patients with moderate renal impairment, a dose of 30mg twice-daily is recommended 3
• No dosing adjustments are required for patients with mild renal impairment 3
• It is also recommended to consider the patient's body mass when determining the dose, with higher doses recommended for patients with larger body mass 4

Considerations for Dosing

When determining the dose of oseltamivir for an elderly patient with impaired renal function, the following factors should be considered:

• The degree of renal impairment, as measured by creatinine clearance 3
• The patient's body mass, as higher doses may be required for patients with larger body mass 4
• The importance of achieving therapeutic concentrations of oseltamivir carboxylate (OC) early in the course of the infection 4

Pharmacokinetics and Efficacy

The pharmacokinetics and efficacy of oseltamivir in patients with renal impairment have been studied, and the results suggest that:

• Oseltamivir is renally cleared, and dose reductions are necessary for patients with renal impairment 4, 3
• The current dosing recommendations for oseltamivir may not provide adequate therapeutic concentrations in patients with mild to moderate renal impairment and/or large body mass 4
• Therapeutic drug monitoring may be useful in optimizing dosing and improving patient outcomes 4