The Effect of β-Blocker Use on Cyclosporine Level in Cardiac Transplant Recipients

Carvedilol, but not metoprolol, was associated with a significant increase in CsA levels after initiation in cardiac transplant recipients. Although carvedilol and CsA do not interact at the level of cytochrome P450 system, it appears that carvedilol influences CsA levels through its effects on P-gp. An average reduction of 10% is necessary on the CsA dose upon initiation of carvedilol, and close follow-up of the level is essential.