BACKGROUND: Whether the enteric absorption of the neuraminidase inhibitor oseltamivir is impaired in critically ill patients is unknown. We documented the pharmacokinetic profile of oseltamivir in patients admitted to intensive care units (ICUs) with suspected or confirmed pandemic (H1N1) influenza. METHODS: We included 41 patients 18 years of age and older with suspected or confirmed pandemic (H1N1) influenza who were admitted for ventilatory support to nine ICUs in three cities in Canada and Spain. Using tandem mass spectrometry, we assessed plasma levels of oseltamivir free base and its active metabolite carboxylate at baseline (before gastric administration of the drug) and at 2, 4, 6, 9 and 12 hours after the fourth or later dose. RESULTS: Among the 36 patients who did not require dialysis, the median concentration of oseltamivir free base was 10.4 (interquartile range [IQR] 4.8-14.9) microg/L; the median concentration of the carboxylate metabolite was 404 (IQR 257-900) microg/L. The volume of distribution of the carboxylate metabolite did not increase with increasing body weight (R2=0.00, p=0.87). The rate of elimination of oseltamivir carboxylate was modestly correlated with estimations of creatinine clearance (R2=0.27, p<0.001). Drug clearance in the five patients who required continuous renal replacement therapy was about one-sixth that in the 36 patients with relatively normal renal function. INTERPRETATION: Oseltamivir was well absorbed enterically in critically ill patients admitted to the ICU with suspected or confirmed pandemic (H1N1) influenza. The dosage of 75 mg twice daily achieved plasma levels that were comparable to those in ambulatory patients and were far in excess of concentrations required to maximally inhibit neuraminidase activity of the virus. Adjustment of the dosage in patients with renal dysfunction requiring continuous renal replacement therapy is appropriate; adjustment for obesity does not appear to be necessary.
BACKGROUND: Whether the enteric absorption of the neuraminidase inhibitor oseltamivir is impaired in critically illpatients is unknown. We documented the pharmacokinetic profile of oseltamivir in patients admitted to intensive care units (ICUs) with suspected or confirmed pandemic (H1N1) influenza. METHODS: We included 41 patients 18 years of age and older with suspected or confirmed pandemic (H1N1) influenza who were admitted for ventilatory support to nine ICUs in three cities in Canada and Spain. Using tandem mass spectrometry, we assessed plasma levels of oseltamivir free base and its active metabolite carboxylate at baseline (before gastric administration of the drug) and at 2, 4, 6, 9 and 12 hours after the fourth or later dose. RESULTS: Among the 36 patients who did not require dialysis, the median concentration of oseltamivir free base was 10.4 (interquartile range [IQR] 4.8-14.9) microg/L; the median concentration of the carboxylate metabolite was 404 (IQR 257-900) microg/L. The volume of distribution of the carboxylate metabolite did not increase with increasing body weight (R2=0.00, p=0.87). The rate of elimination of oseltamivir carboxylate was modestly correlated with estimations of creatinine clearance (R2=0.27, p<0.001). Drug clearance in the five patients who required continuous renal replacement therapy was about one-sixth that in the 36 patients with relatively normal renal function. INTERPRETATION:Oseltamivir was well absorbed enterically in critically illpatients admitted to the ICU with suspected or confirmed pandemic (H1N1) influenza. The dosage of 75 mg twice daily achieved plasma levels that were comparable to those in ambulatory patients and were far in excess of concentrations required to maximally inhibit neuraminidase activity of the virus. Adjustment of the dosage in patients with renal dysfunction requiring continuous renal replacement therapy is appropriate; adjustment for obesity does not appear to be necessary.
Authors: S Bantia; C D Parker; S L Ananth; L L Horn; K Andries; P Chand; P L Kotian; A Dehghani; Y El-Kattan; T Lin; T L Hutchison; J A Montgomery; D L Kellog; Y S Babu Journal: Antimicrob Agents Chemother Date: 2001-04 Impact factor: 5.191
Authors: Anand Kumar; Ryan Zarychanski; Ruxandra Pinto; Deborah J Cook; John Marshall; Jacques Lacroix; Tom Stelfox; Sean Bagshaw; Karen Choong; Francois Lamontagne; Alexis F Turgeon; Stephen Lapinsky; Stéphane P Ahern; Orla Smith; Faisal Siddiqui; Philippe Jouvet; Kosar Khwaja; Lauralyn McIntyre; Kusum Menon; Jamie Hutchison; David Hornstein; Ari Joffe; Francois Lauzier; Jeffrey Singh; Tim Karachi; Kim Wiebe; Kendiss Olafson; Clare Ramsey; Sat Sharma; Peter Dodek; Maureen Meade; Richard Hall; Robert A Fowler Journal: JAMA Date: 2009-10-12 Impact factor: 56.272
Authors: Sarah C Welch; Simon W Lam; Elizabeth A Neuner; Seth R Bauer; Stephanie N Bass Journal: Intensive Care Med Date: 2015-05-08 Impact factor: 17.440
Authors: Timothy M Uyeki; Henry H Bernstein; John S Bradley; Janet A Englund; Thomas M File; Alicia M Fry; Stefan Gravenstein; Frederick G Hayden; Scott A Harper; Jon Mark Hirshon; Michael G Ison; B Lynn Johnston; Shandra L Knight; Allison McGeer; Laura E Riley; Cameron R Wolfe; Paul E Alexander; Andrew T Pavia Journal: Clin Infect Dis Date: 2019-03-05 Impact factor: 9.079
Authors: Barbara J Brennan; Brian Davies; Georgina Cirrincione-Dall; Peter N Morcos; Anna Beryozkina; Colombe Chappey; Pau Aceves Baldó; Sian Lennon-Chrimes; Craig R Rayner Journal: Antimicrob Agents Chemother Date: 2012-06-25 Impact factor: 5.191
Authors: Enno D Wildschut; Matthijs de Hoog; Maurice J Ahsman; Dick Tibboel; Albert D M E Osterhaus; Pieter L A Fraaij Journal: PLoS One Date: 2010-06-03 Impact factor: 3.240