Study of the Relative Oral Bioavailability of the Antiflu Medicine Oseltamivir in the Intensive Care Unit

A Study of the Relative Oral Bioavailability of the Antiflu Medicine Oseltamivir (Tamiflu®) in Patients in the Intensive Care Unit

This proposed pharmacokinetic study will test the hypothesis that in critically ill patients with respiratory failure requiring mechanical ventilation such as might be anticipated to be needed to treat patients with severe influenza pneumonia, oseltamivir administered enterally via nasogastric tube, with and without concomitant food or alimentation, will have similar oral bioavailability to that observed in ambulatory adults ill with influenza in whom oseltamivir therapy 75 mg BID is efficacious and well tolerated. Additionally, this experiment will test the hypothesis that increasing the dose (150 mg), with and without concomitant enteral feeding, will show a proportionate increase in bioavailability. Relative oral bioavailability will be assessed from plasma concentration vs. time over 12 hrs and urinary recovery of drug from 0 to 48 hrs after administration.

Not required

Inclusion Criteria:

• patients admitted to the Intensive Care Unit requiring mechanical ventilation due to respiratory failure
• must be within the ages of 18-75 yrs

Exclusion Criteria:

• patients unable to have enteral feeding
• intolerance to oseltamivir
• pregnancy
• gastrointestinal or malabsorptive disease
• intestinal bypass surgery
• diarrhea (>2 loose bowel movements per day)
• receipt of prokinetic medications (metoclopramide, domperidone, erythromycin)
• severe liver disease (hepatocellular enzymes > 3 times the upper limit of normal)
• renal failure (Cockroft-Gault Creatinine Clearance < 30 ml/min, Dialysis dependant)
• cystic fibrosis
• intoxication or drug overdose