Drug therapy in the heart transplant recipient part IV: drug–drug interactions. Circulation

Continued improvement in the long-term survival of hearttransplant recipients has resulted in a population of patients with prolonged exposure to immunosuppressive drugs.1 This exposure, coupled with the increasing age of recipients, has resulted in an impressive prevalence of comor-bidities in these patients. Indeed, by 5 years after transplan-tation, 95 % of recipients have hypertension, 81 % have hyperlipidemia, and 32 % have diabetes.1 In addition, 25 % to 50 % have coronary allograft vasculopathy (CAV), and up to 33 % have chronic renal insufficiency.2–5 As more drugs are developed to both prevent and treat these problems and common infectious complications after transplantation, it is likely that the heart transplant recipient will be taking an increasing number of drugs. Because standard immunosup-pressive drugs have a high potential for drug–drug interac-tions, the heart transplant recipient is subject to an enormou