METABOLISM OF PENTAERYTHRITOL TETRANITRATE BY PATIENTS WITH CORONARY ARTERY DISEASE

¹ Biochemistry Department, Warner-Lambert Research Institute, Morris Plains, New Jersey and Beth Israel Hospital, Newark, New Jersey

A single dose of radioactive pentaerythritol tetranitrate (ETN) was taken orally by 5 patients who had experienced acute myocardial infarctions and by a control group. Blood samples and urine collected from these subjects were assayed quantitatively for total radio-activity, for PETN and for PETN metabolites. The blood of the control group contained slightly more radioactivity than did samples from the coronary patients. Both groups showed peak radioactivity levels in blood from 2 to 4 hr following treatment. During that period, approximately 4.5% of the dose was in the circulatory system and the radioactive compounds present were pentaerythritol (PE), PE-mononitrate and PE-dinitrate. Twenty-four hours after treatment, the blood still contained PE and PE-mononitrate. Qualitatively and quantitatively, the excretion patterns exhibited by the control and coronary groups were practically identical. In 24 hr, both groups excreted about 34% of the C¹⁴ administered. The principal urinary metabolite was PE-mononitrate (57%). Also present were PE (40%) and PE-dinitrate (3%).