TAC is commonly prescribed in KTX recipients, though overexposure can be nephrotoxic. CIVN, used to treat post-KTX hypertension, may inhibit TAC metabolism resulting in overexposure and potential toxicity. We present two case reports and analysis of 2068 KTXs from the PHIS to characterize post-KTX intravenous anti-hypertensive use and to determine whether CIVN in TAC-treated patients would predict "immunosuppressive drug causing adverse effects in therapeutic use" (E-code E9331). CIVN was ordered in 11% of KTXs and prescribing increased from 6.2% in 2003 to 10.3% in 2008 (p=0.003, Mantel-Haenszel chi-square test). AEI were reported in 7.1% of TAC-treated patients with CIVN orders compared to 3% of those without (p=0.003, chi-square test). In univariate analysis using GEEs, AEI were twofold more likely in patients with CIVN orders than patients without (AOR 2.1, 95% CI 1.03-4.17) and threefold more likely than patients with orders for other continuous intravenous anti-hypertensives (AOR 3.2, 95% CI 1.09-9.08). In multivariate analysis, only CIVN significantly predicted AEI (AOR 2.8, 95% CI 1.29-6.04). Thus, until clinical studies to fully characterize this interaction are completed, CIVN should be used with caution in TAC-treated individuals.
© 2010 John Wiley & Sons A/S.