Pulmonary hypertension in first episode infective endocarditis among intravenous buprenorphine users: case report

Since the Food and Drug Administration (FDA) approved the use of buprenorphine hydrochloride (Subutex) for the treatment of opiate dependence in 2002, there has been a global trend of its IV abuse which led to life-threatening medical complications such as infective endocarditis (IE), cardiac failure, and death.

First episode IE were identified in 14 patients (prevalence of 10.8%) among 130 IV buprenorphine abusers who presented to the National University Hospital, Singapore between 2004 to 2006. The variables that were examined in the present study included age, gender, ethnicities, duration of symptoms, types of valves, laboratory, microbiology, echocardiographic features, types of antibiotics given, duration of hospitalization, and the mortality rate.

While the majority of these patients presented predominantly with pleuropneumonic symptoms and had tricuspid-valve vegetations with Staphylococcus aureus being the commonest causative organism as reported in other IV drug abusers, pulmonary arterial hypertension (PHT) seemed peculiarly common (79%), and the mortality (21%) was higher in our patients compared to previously reported series (5-10%). Univariate linear regression revealed no relationship between PHT and the presence of septic pulmonary emboli (p =.284) and pulmonary embolism (p =.777).

PHT may contribute to morbidity and mortality amongst IV buprenorphine abusers. A high index of suspicion of PHT is required in treating IV buprenorphine abusers who presented with pleuropneumonic symptoms. The absence of a relationship between PHT and pulmonary embolism underscores the possibility of the contribution of buprenorphine to PHT, which have been demonstrated in a number of animal studies.