Table 1.

Comparison of Hair Concentrations of Nevirapine Analyzed by Thin-Layer Chromatography and by Liquid Chromatography/Tandem Mass Spectrometry Methods in Five HIV-Infected Patients on Nevirapine-Based Therapy

Sample ID	Antiretrovirals coadministered with NVP	Semiquantitative concentration of NVP with the TLC method (ng/mg hair)	Concentration of NVP with the LC-MS/MS method (ng/mg hair)
1	Tenofovir, emtricitabine	10–25	21.7
2	Tenofovir, emtricitabine	25–50	33.4
3	Atazanavir/ritonavir; lamivudine, tenofovir	10–25	16.3
4	Atazanavir/ritonavir; tenofovir	25–50	43.9
5	Stavudine, lamivudine	25–50	44.2

NVP, nevirapine; TLC, thin-layer chromatography; LC-MS/MS, liquid chromatogrpahy/tandem mass spectrometry.