Hossein Karballaei-Mirzahosseini1, Romina Kaveh-Ahangaran1, Bita Shahrami1, Mohammad Reza Rouini2, Atabak Najafi3, Arezoo Ahmadi3, Sima Sadrai2, Amirmahdi Mojtahedzadeh4, Farhad Najmeddin5,6, Mojtaba Mojtahedzadeh1,7. 1. Department of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, 16-Azar St., Enghelab Ave., Tehran, 14176-14418, Iran. 2. Department of Pharmaceutics, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. 3. Department of Anesthesiology and Critical Care, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 4. Faculty of Medicine, Semmelweis University, Budapest, Hungary. 5. Department of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, 16-Azar St., Enghelab Ave., Tehran, 14176-14418, Iran. farhad.najm@gmail.com. 6. Research Center for Rational Use of Drugs, Tehran University of Medical Sciences, Tehran, Iran. farhad.najm@gmail.com. 7. Research Center for Rational Use of Drugs, Tehran University of Medical Sciences, Tehran, Iran.
Abstract
PURPOSE: Although rifampicin (RIF) is used as a synergistic agent for multidrug-resistant Acinetobacter baumannii (MDR-AB) infection, the optimal pharmacokinetic (PK) indices of this medication have not been studied in the intensive care unit (ICU) settings. This study aimed to evaluate the PK of high dose oral RIF following fasting versus fed conditions in terms of achieving the therapeutic goals in critically ill patients with MDR-AB infections. METHODS: 29 critically ill patients were included in this study. Under fasting and non-fasting conditions, RIF was given at 1200 mg once daily through a nasogastric tube. Blood samples were obtained at seven time points: exactly before administration of the drug, and at 1, 2, 4, 8, 12, and 24 h after RIF ingestion. To quantify RIF in serum samples, high-performance liquid chromatography (HPLC) was used. The MONOLIX Software and the Monte Carlo simulations were employed to estimate the PK parameters and describe the population PK model. RESULTS: The mean area under the curve over the last 24-h (AUC0-24) value and accuracy (mean ± standard deviation) in the fasting and fed states were 220.24 ± 119.15 and 290.55 ± 276.20 μg × h/mL, respectively. There was no significant difference among AUCs following fasting and non-fasting conditions (P > 0.05). The probability of reaching the therapeutic goals at the minimum inhibitory concentration (MIC) of 4 mg/L, was only 1.6%. CONCLUSION: In critically ill patients with MDR-AB infections, neither fasting nor non-fasting administrations of high-dose oral RIF achieve the therapeutic aims. More research is needed in larger populations and with measuring the amount of protein-unbound RIF levels.
PURPOSE: Although rifampicin (RIF) is used as a synergistic agent for multidrug-resistant Acinetobacter baumannii (MDR-AB) infection, the optimal pharmacokinetic (PK) indices of this medication have not been studied in the intensive care unit (ICU) settings. This study aimed to evaluate the PK of high dose oral RIF following fasting versus fed conditions in terms of achieving the therapeutic goals in critically ill patients with MDR-AB infections. METHODS: 29 critically ill patients were included in this study. Under fasting and non-fasting conditions, RIF was given at 1200 mg once daily through a nasogastric tube. Blood samples were obtained at seven time points: exactly before administration of the drug, and at 1, 2, 4, 8, 12, and 24 h after RIF ingestion. To quantify RIF in serum samples, high-performance liquid chromatography (HPLC) was used. The MONOLIX Software and the Monte Carlo simulations were employed to estimate the PK parameters and describe the population PK model. RESULTS: The mean area under the curve over the last 24-h (AUC0-24) value and accuracy (mean ± standard deviation) in the fasting and fed states were 220.24 ± 119.15 and 290.55 ± 276.20 μg × h/mL, respectively. There was no significant difference among AUCs following fasting and non-fasting conditions (P > 0.05). The probability of reaching the therapeutic goals at the minimum inhibitory concentration (MIC) of 4 mg/L, was only 1.6%. CONCLUSION: In critically ill patients with MDR-AB infections, neither fasting nor non-fasting administrations of high-dose oral RIF achieve the therapeutic aims. More research is needed in larger populations and with measuring the amount of protein-unbound RIF levels.