No serious complications, such as bleeding, allergy or hypotension, were noted.<h4>Conclusion</h4>We present case series of 4 patients with purulent pericarditis, in whom direct intrapericardial administration of recombinant tissue plasminogen activator (r-tPA), prevented the development of constrictive pericarditis, and increased efficacy of antibiotic treatment without any significant complications. This evidence concerns the gene PLAT and Allergy.