Therapeutic Drug Monitoring in Patients Coinfected with Human Immunodeficiency Virus and Disseminated Mycobacterium avium Complex

Abstract

In patients infected with human immunodeficiency virus (HIV), antiretroviral therapy has decreased the risk of progression to acquired immunodeficiency syndrome or death significantly. However, many individuals still present with an opportunistic infection as the first clinical manifestation of HIV infection. This complicates therapy due to frequent and complex drug interactions between antiretrovirals and the drugs used to treat the opportunistic infection. We describe a 48‐year‐old man coinfected with HIV and disseminated Mycobacterium avium complex (MAC). His treatment for MAC started about 2 weeks before he started antiretroviral therapy. The MAC regimen consisted of clarithromycin 500 mg/day, ethambutol 1200 mg/day, rifabutin 150 mg every other day, and ciprofloxacin 500 mg twice/day. His antiretroviral therapy consisted of atazanavir 300 mg/day, ritonavir 100 mg/day, and emtricitabine 200 mg‐tenofovir 300 mg/day. Approximately 95 days after receiving these concomitant therapies, his rifabutin peak concentration was 0.08 μg/ml (goal peak concentration > 0.45 μg/ml); thus, the dosage of rifabutin was increased to 300 mg every other day. Fourteen days later, his rifabutin peak concentration was 0.43 μg/ml. Drug interactions between antiretrovirals and antimycobacterials are complex and not fully understood in patients with HIV infection. Although the recommended dosage of rifabutin in patients receiving a ritonavir‐boosted protease inhibitor, such as atazanavir, is 150 mg every other day, higher dosages may be required to attain optimal rifabutin concentrations in patients receiving these drugs concomitantly.

Diversity of cloacal microbial community in migratory shorebirds that use the Tagus estuary as stopover habitat and their potential to harbor and disperse pathogenic microorganisms

“…Strains from these genera are referred to as the cause of economic losses in livestock, frequently associated to elevated levels of water pollution (Sousa & Silva-Souza, 2001;Johnson et al, 2007). Furthermore, some species belonging to these genera are also reported as opportunistic pathogens for humans, causing human infections (Jourdain et al, 2007;Mattos-Guaraldi et al, 2008;Aspán & Eriksson, 2010;Dunn et al, 2011;Vignaroli et al, 2011).…”