Objective: Coronary artery disease is one of the leading causes of morbidity and mortality 
in populations. In opium abusers, level of circulating coagulation factors differs from nonabusers. The aim of this study was to evaluate response to thrombolytic therapy in opium 
abusers vs. non-abusers.
Methods: In this prospective observational study, 83 patients (36 opium abusers and 47 nonabusers) with AMI were evaluated for the presence and degree of response to thrombolytic 
agent. All patients were monitored for electrocardiographic changes and response to 
thrombolysis 2 hours before and after administration of thrombolytic agent. Serum CPK 
and LDH were measured 2 hours before and after thrombolysis. Quantitative and qualitative 
data were analyzed by independent t-test and chi-square using SPSS, respectively.
Findings: ST-resolution 2 hours after thrombolysis was 63.8% and 44.4% in opium users and 
non-users, respectively. Serum level of CPK cardiac biomarker 2 hours after thrombolysis 
was 980 ± 245 and 847 ± 130 IU/L in opium users and non-users, respectively.
Conclusion: Our data demonstrate that in those patients with opium abuse, 
electrocardiographic changes after thrombolysis were significantly lower than opium nonusers (P < 0.05). Opium users showed better ST-resolution compared with non-users. Opium 
addiction had effect on cardiac enzymes despite their effect on response to streptokinase.