“…For example, in patients on long-term intravenous NTG infusions at doses ranging from 1.3 to 12.0 mg/hour for 1 to 16 days, Torfgard et al [43] observed plasma concentrations of 0.8 to 894.5 ng/ml for NTG, undetected to 119.5 ng/ml (for 1,2-GDN), and 0.8–42.2 ng/ml (for 1,3-GDN), respectively. The composite plasma concentrations observed after transdermal NTG administration, at doses of 5 to 105 mg per day, ranged from 0.1 to 9.24 ng/ml (NTG), 0.3–3.5 ng/ml (1,2-GDN), and 0.5–0.8 ng/ml (1,3-GDN), respectively [36; 38; 39; 40; 41; 42; 44; 45]. The plasma concentrations observed in the present study, i.e., NTG: 0.3 to 0.7 ng/ml, 1,2-GDN: 2 to 23 ng/ml, and 1,3-GDN: 1.2 –11 ng/ml, were well within these clinically observed values.…”