SETTING: Three US referral hospitals. OBJECTIVE: Determine the population pharmacokinetic (PK) parameters of ethionamide (ETA) following multiple oral doses. DESIGN: Fifty-five patients with tuberculosis (TB) participated. Patients received multiple oral doses of ETA as part of their treatment. They also received other anti-tuberculosis medications based upon in vitro susceptibility data. Serum samples were collected over 12 h post-dose, and concentrations were determined using a validated high-performance liquid chromatography (HPLC) assay. Concentration-time data were analyzed using population methods. RESULTS: ETA areas under the concentration-versus-time curve (AUCs) increased linearly with increasing oral doses from 250 to 1000 mg. Compared to the population pattern, delayed absorption was seen at least once in 15% of patients. ETA PK parameter estimates were independent of age, weight, height, gender, and creatinine clearance. TB patients appeared to have larger volumes of distribution (3.22 l/kg) and clearance values (1.88 l/h/kg) compared to previously studied healthy volunteers. This resulted in lower AUC values (3.95 mcg h/ml) in the TB patients. ETA displayed a short elimination half-life (1.94 h). The effect of different dosing strategies on calculated pharmacodynamic parameters was explored. Simulated doses of 250 mg BID to TID failed to achieve serum concentrations above the MIC. CONCLUSION: ETA PK parameters differed between TB patients and healthy volunteers, possibly due to differences in the completeness of absorption. Doses of at least 500 mg appear to be required to achieve serum concentrations above the typical ETA MIC. Additional research is needed to determine the optimal dosing of ETA.
SETTING: Three US referral hospitals. OBJECTIVE: Determine the population pharmacokinetic (PK) parameters of ethionamide (ETA) following multiple oral doses. DESIGN: Fifty-five patients with tuberculosis (TB) participated. Patients received multiple oral doses of ETA as part of their treatment. They also received other anti-tuberculosis medications based upon in vitro susceptibility data. Serum samples were collected over 12 h post-dose, and concentrations were determined using a validated high-performance liquid chromatography (HPLC) assay. Concentration-time data were analyzed using population methods. RESULTS: ETA areas under the concentration-versus-time curve (AUCs) increased linearly with increasing oral doses from 250 to 1000 mg. Compared to the population pattern, delayed absorption was seen at least once in 15% of patients. ETA PK parameter estimates were independent of age, weight, height, gender, and creatinine clearance. TB patients appeared to have larger volumes of distribution (3.22 l/kg) and clearance values (1.88 l/h/kg) compared to previously studied healthy volunteers. This resulted in lower AUC values (3.95 mcg h/ml) in the TB patients. ETA displayed a short elimination half-life (1.94 h). The effect of different dosing strategies on calculated pharmacodynamic parameters was explored. Simulated doses of 250 mg BID to TID failed to achieve serum concentrations above the MIC. CONCLUSION: ETA PK parameters differed between TB patients and healthy volunteers, possibly due to differences in the completeness of absorption. Doses of at least 500 mg appear to be required to achieve serum concentrations above the typical ETA MIC. Additional research is needed to determine the optimal dosing of ETA.
Authors: Kelly E Dooley; Carole D Mitnick; Mary Ann DeGroote; Ekwaro Obuku; Vera Belitsky; Carol D Hamilton; Mamodikoe Makhene; Sarita Shah; James C M Brust; Nadza Durakovic; Eric Nuermberger Journal: Clin Infect Dis Date: 2012-05-21 Impact factor: 9.079
Authors: Mohammad H Al-Shaer; Anne-Grete Märtson; Wael A Alghamdi; Abdullah Alsultan; Guohua An; Shahriar Ahmed; Yosra Alkabab; Sayera Banu; Eric R Houpt; David Ashkin; David E Griffith; J Peter Cegielski; Scott K Heysell; Charles A Peloquin Journal: Antimicrob Agents Chemother Date: 2020-08-20 Impact factor: 5.191
Authors: Wilfried Weber; Ronald Schoenmakers; Bettina Keller; Marc Gitzinger; Thomas Grau; Marie Daoud-El Baba; Peter Sander; Martin Fussenegger Journal: Proc Natl Acad Sci U S A Date: 2008-07-09 Impact factor: 11.205