Abstract
Following a single 50 mg dose of hydralazine (Apresoline®) in 13 patients with impaired renal function, a decrease in glomerular filtration rate (GFR) was correlated with an increase in serum half-life (T1/2) of the drug (r=−0.69; p−1, as compared to a T1/2 of 1.7–3.0 h found previously in 16 healthy volunteers. In 49 patients on long-term antihypertensive treatment with hydralazine, the ratio between the minimum steady-state drug concentration and the daily dose of hydralazine (C SS min : Dose) increased as the GFR decreased. This accumulation of the drug was particularly evident in patients with a GFR less than 30 ml·min−1 (r=−0.63; p−1 in urine could be recovered after storage of the samples at room temperature for 24 h.