Acetaminophen and experimental acute myocardial infarction.
Acetaminophen is a widely used analgesic, and recent studies have shown that it has some benefits in the ischemic heart. The purpose of this study was to test the effects of acetaminophen on infarct size, regional myocardial blood flow and the "no-reflow" phenomenon in a rabbit model of coronary artery occlusion (CAO) and reperfusion. Rabbits were assigned to one of four groups: (1) acetaminophen, 75 mg/kg in 75% ethanol, 30 min before CAO, (2) vehicle at 30 min before CAO, (3) acetaminophen at 18 min after CAO (12 min before reperfusion), or (4) vehicle at 18 min of CAO ( n = 10 each group). All rabbits received 30 min of CAO followed by 3 hr reperfusion. The extent of ischemia was similar in all groups comprising 24-27% of the left ventricle. Infarct size (% ischemic zone) was 51 +/- 5, 56 +/- 3 in groups 1 and 2 ( p = ns), 43 +/- 3 and 40 +/- 4 in groups 3 and 4 ( p = ns). Thus acetaminophen did not affect the development of necrosis. Heart rate and blood pressure were unchanged by acetaminophen treatment. Regional myocardial blood flow was similar in all groups during occlusion and at the end of reperfusion. Acetaminophen had no effect on the size of the anatomic zone of no-reflow that developed by 3 hours of reperfusion. We conclude that acetaminophen has a neutral effect in this experimental model of ischemia/reperfusion and appears to be safe in the course of experimental myocardial infarction.
Hale
Sharon L
SL
The Heart Institute of Good Samaritan Hospital, and the University of Southern California, Department of Medicine, Division of Cardiovascular Medicine, Los Angeles, CA 90017, USA. sharon.hale@attglobal.net
Kloner
Robert A
RA
D000082:Acetaminophen / Q000627:therapeutic use*; D018712:Analgesics, Non-Narcotic / Q000627:therapeutic use*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000188:drug therapy*; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000473:pathology; D015425:Myocardial Reperfusion; D011817:Rabbits
D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen