THE EFFECT OF SIMULTANEOUS INTRAVENOUS ADMINISTRATION OF NITROGLYCERIN AND HEPARIN ON PARTIAL THROMBOPLASTIN TIME

The purpose of this study was to determine whether intravenous nitrogl ycerin, when infused simultaneously through the same tubing with hepar in, alters the anticoagulant effect of heparin as evidenced by partial thromboplastin time (PTT) values. A time series, cross-over design wa s used. The study included patients admitted to the Coronary Care Unit with a diagnosis of unstable angina. Patients were randomly as signed to one of two treatment groups: (1) heparin/nitroglycerin infused in the same site or (2) heparin/nitroglycerin in fused in separate sites. After 18 hours, treatments were reversed, PTT results were measured s even times per subject. Ninety-eight subjects, 70 males and 28 females , participated. Mean age was 62.4 +/- 9 years. Using repeated measures anal ysis of variance, there was no change in the patients' PTTs (p = 0.47). Prior to this study, research was divided on whether nitroglyc erin interferes with heparin's activity. This study indicates no signi ficant difference in PTT in subjects receiving these infusions via sep arate or the same intravenous sites.