Case report lack of PK interaction between bosentan and nevirapine
This case report describes the successful treatment of pulmonary arterial hypertension using bosentan in a woman receiving nevirapine, lamivudine and zidovudine. Due to concerns about a potential drug interaction with nevirapine (bosentan is a substrate of OATP, CYP3A4 and CYP2C9 and is also an inducer of these cytochrome P450s), nevirapine plasma concentrations, CD4 count and viral were extensively monitored.
Throughout the four-year follow up, no effect of bosentan on nevirapine was observed. Nevirapine trough concentrations were maintained between approximately 5.0 and 6.5 ug/mL, despite a doubling of bosentan dose (from 62.5 mg to 125 mg twice daily, although the authors do not indicate if this increase was related to nevirapine induction). Viral load remained below 75 copies/mL and significant clinical and haemodynamic improvement was noted.
Source: www.hiv-druginteractions.org (15 July 2010).
Hardy H et al. Successful bosentan and NNRTI-based therapy in a patient with AIDS and pulmonary arterial hypertension. Pharmacotherapy, 2010, 30(4): 139e-144e. http://www.ncbi.nlm.nih.gov/pubmed/20334465