Safety and pharmacologic activity of a new nitrate ester, ITF 296, after intravenous administration in healthy volunteers

Abstract

To evaluate the safety and pharmacologic activity of ITF 296 in humans, three groups of healthy male normotensive subjects were studied. The first two groups (six subjects each) received, in ascending order, three dose levels of ITF 296 by 30-min intravenous infusion (group I, 0.1, 0.5, 1.0 microgram/kg/min; group II, 2.0, 4.0, 6.0 micrograms/kg/min). The third group of eight subjects received, in ascending order, four dose levels of ITF 296 (10, 20, 40, 80 micrograms/kg) by 1-min i.v. injection. The study was double-blind, and placebo-controlled according to a within-patient, incomplete, unbalanced block design, such that each subject received the placebo once. Hemodynamics were assessed by means of Dynamap and BOMED. The following parameters were evaluated at different times before and after ITF 296 administration: systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), stroke volume index (SVI), cardiac index (CI), and systemic vascular resistance index (SVRI). Blood samples for kinetic assessment of ITF 296 were taken before and at different times after ITF 296 administration. The drug was well tolerated. Only a few mild (except for one, moderate) side effects (mainly headache and dizziness) were reported, usually at the higher dose levels. All safety clinical chemistry and hematologic parameters were unaffected. After i.v. infusion of ITF 296, blood pressure started to fall at the dose of 2 micrograms/kg/min, DBP being significantly reduced at doses above 1 microgram/kg/min. The effect lasted for up to 60 min after the end of the infusion. The increase in heart rate was only modest, although apparently dose-dependent. SVI was only slightly reduced, and the other hemodynamic parameters did not change. After bolus administration of ITF 296, SBP was significantly reduced starting at a dose of 20 micrograms/kg with higher doses producing a more marked effect (up to -15 mm Hg). DBP was significantly reduced only at the higher dose level of 80 micrograms/kg. The effect lasted for up to 60 min after bolus administration. HR was slightly increased after doses of 40 and 80 micrograms/kg. SVI was slightly reduced and a small transient decrease in CI was observed, whereas SVRI did not change. Satisfactory, linear kinetic correlation was found between total doses administered and AUCs measured. ITF 296 in healthy male normotensive volunteers was effective and well tolerated. The results of this study justify the planning of further studies in patients in order to test the anti-ischemic activity of the compound.