This article describes the potential for lethal abuse of central venous catheters in oncology patients and its effects especially on the cardiovascular system. Central venous catheters are frequently used to provide immediate vascular access allowing patients to obtain lifesaving therapy or have painless blood-drawing procedures. However, they may also serve as a vehicle for abuse and misuse of medications increasing the potential for morbidity and mortality. We present a unique instance where a pediatric patient attempted suicide by self-injecting crushed diphenhydramine (Benadryl) capsules into her central venous catheter. The patient developed acute but transient ST segment elevation and echocardiographic evidence of severe pulmonary hypertension. She was treated symptomatically with oxygen and diuretics over a period of weeks, while her pulmonary hypertension completely resolved. The injection of oral medications into the central circulation is typically associated with transient pulmonary hypertension and clinical features of pulmonary embolism, especially in preparations containing talc. Although the pulmonary hypertension can be transient, it could be fatal. Physicians must be alert to the potential for abuse and misuse of central venous catheters especially in the chronically ill pediatric patients.