BACKGROUND: Efavirenz is among the most widely used antiretroviral drugs. Increased efavirenz exposure has been associated with CNS side effects and also with the chance of emergence of resistance upon treatment interruptions. The objective of this study was to evaluate factors associated with efavirenz plasma concentrations in a cohort of HIV-infected individuals. METHODS: From July 2009 to March 2010, HIV-infected patients with efavirenz as part of antiretroviral therapy (600 mg at night), undetectable viral load for at least 1 year and CD4 cell count >200 cells/mm(3) were consecutively enrolled at the HIV/AIDS ambulatory care unit in southern Brazil. Plasma samples were taken 18-23 h after efavirenz last dose and analysed by validated ultra-performance liquid chromatography. RESULTS: Forty-one subjects were included (21 females). Mean age and weight were 45.4 years and 70.9 kg, respectively. Mean efavirenz plasma concentration was 2.20 ± 2.17 mg/L. Most plasma concentrations (73%) were within the therapeutic window (1-4 mg/L); 17% were below and 10% above the limits. There were no significant associations between efavirenz concentration and age, CD4 cell count, time on antiretroviral treatment and gender. There was significant and inverse correlation between efavirenz concentrations and body weight (P = 0.013) and body mass index (P = 0.001). CONCLUSIONS: In this cohort of well-controlled HIV-positive individuals, patients with lower weight or body mass index had a higher chance of presenting elevated plasma concentrations of efavirenz. Therapeutic drug monitoring to adjust dose might be a helpful tool to decrease efavirenz dose in order to minimize costs and adverse effects.
BACKGROUND: Efavirenz is among the most widely used antiretroviral drugs. Increased efavirenz exposure has been associated with CNS side effects and also with the chance of emergence of resistance upon treatment interruptions. The objective of this study was to evaluate factors associated with efavirenz plasma concentrations in a cohort of HIV-infected individuals. METHODS: From July 2009 to March 2010, HIV-infectedpatients with efavirenz as part of antiretroviral therapy (600 mg at night), undetectable viral load for at least 1 year and CD4 cell count >200 cells/mm(3) were consecutively enrolled at the HIV/AIDS ambulatory care unit in southern Brazil. Plasma samples were taken 18-23 h after efavirenz last dose and analysed by validated ultra-performance liquid chromatography. RESULTS: Forty-one subjects were included (21 females). Mean age and weight were 45.4 years and 70.9 kg, respectively. Mean efavirenz plasma concentration was 2.20 ± 2.17 mg/L. Most plasma concentrations (73%) were within the therapeutic window (1-4 mg/L); 17% were below and 10% above the limits. There were no significant associations between efavirenz concentration and age, CD4 cell count, time on antiretroviral treatment and gender. There was significant and inverse correlation between efavirenz concentrations and body weight (P = 0.013) and body mass index (P = 0.001). CONCLUSIONS: In this cohort of well-controlled HIV-positive individuals, patients with lower weight or body mass index had a higher chance of presenting elevated plasma concentrations of efavirenz. Therapeutic drug monitoring to adjust dose might be a helpful tool to decrease efavirenz dose in order to minimize costs and adverse effects.
Authors: Cindy J Bednasz; Charles S Venuto; Qing Ma; Eric S Daar; Paul E Sax; Margaret A Fischl; Ann C Collier; Kimberly Y Smith; Camlin Tierney; Yang Yang; Gregory E Wilding; Gene D Morse Journal: Ther Drug Monit Date: 2017-12 Impact factor: 3.681
Authors: Alessandra Ruggiero; Alessandro Cozzi-Lepri; Apostolos Beloukas; Douglas Richman; Saye Khoo; Andrew Phillips; Anna Maria Geretti Journal: Open Forum Infect Dis Date: 2018-02-03 Impact factor: 3.835
Authors: Kristen L Bunnell; Arwa Aldossari; Connor Perkins; Christopher Schriever; Thomas D Chiampas; Jeremy D Young; Mahesh C Patel; Melissa Badowski Journal: J Int Assoc Provid AIDS Care Date: 2018 Jan-Dec
Authors: Natália Bordin Andriguetti; Helena Katherina Van Schalkwyk; Daniel Thomas Barratt; Joseph Tucci; Paul Pumuye; Andrew Alexander Somogyi Journal: Clin Transl Sci Date: 2021-08-20 Impact factor: 4.689
Authors: Jacinta N Nwogu; Monica Gandhi; Andrew Owen; Saye H Khoo; Babafemi Taiwo; Adeniyi Olagunju; Baiba Berzins; Hideaki Okochi; Regina Tallerico; Kevin Robertson; Chinedum P Babalola Journal: AIDS Date: 2021-10-01 Impact factor: 4.632