Interactions between hydralazine and oral nutrients in humans

To help clarify whether food or enteral nutrients decrease hydralazine relative bioavailability, eight subjects were given oral hydralazine under four nutritional conditions: fasted (F), with a standard breakfast (SB), with a bolus of enteral nutrients (EB), and with a slow infusion of enteral nutrients administered by nasogastric tube (EI). The area under the curve and maximum concentration values were much higher under the fasted and enteral infusion conditions than under the standard breakfast or enteral bolus conditions, indicating that the absorption and/or disposition kinetics of hydralazine may be altered by food. The median (range) values for these parameters were 2,641 (385-4,747) and 87 (4.5-224) for F; 1,189 (202-1,737) and 15 (3.5-33.9) for SB; 999 (227-3,576) and 11 (2.5-50) for EB; and 3,068 (313-4,917) ng/ml/min and 113 (3.6-235) ng/ml for EI. Furthermore, the rate of nutrient administration, but not necessarily the physical form, of the nutrients appears to be a significant factor in determining the magnitude of the food effect. The nutrient interaction should be accounted for in patients receiving hydralazine and enteral nutrition concomitantly.