CYP2C9 and ABCG2 polymorphisms as risk factors for developing adverse drug reactions in renal transplant patients taking fluvastatin: a case-control study.

Aim: To investigate whether an association exists between fluvastatin-induced adverse drug reactions (ADRs) and polymorphisms in genes encoding the metabolizing enzyme CYP2C9 and the drug transporter ABCG2 in renal transplant recipients (RTRs).

Materials & Methods: Fifty-two RTRs that experienced fluvastatin ADRs and 52 controls matched for age, gender, dose of fluvastatin and immunosuppressive use were enrolled in the study. Genotyping for CYP2C9*2, *3 and ABCG2 421C>A variants was performed by real-time PCR.

Results: CYP2C9 homozygous and heterozygous mutant allele (*2 or *3) carriers had 2.5-times greater odds of developing adverse effects (χ² = 4.370; degrees of freedom = 1; p = 0.037; φ = 0.21, odds ratio [OR]: 2.44; 95% CI: 1.05-5.71). Patients who were the carriers of at least one mutant CYP2C9 allele (*2 or *3) and who were receiving CYP2C9 inhibitors, had more than six-times greater odds of having adverse effects than those without the inhibitor included in their therapy (p = 0.027; OR: 6.59; 95% CI: 1.24-35.08). Patients with ABCG2 421CA or AA (taken together) had almost four-times greater odds of developing adverse effects than those with ABCG2 421CC genotype (χ² = 6.190; degrees of freedom = 1; p = 0.013; φ = 0.24, OR: 3.81; 95% CI: 1.27-11.45). Patients with A allele had 2.75-times (95% CI: 1.02-7.40) greater odds of developing adverse effects than those with C allele.

Conclusion: Our preliminary data demonstrate an association between fluvastatin-induced ADRs in RTRs and genetic variants in the CYP2C9 and ABCG2 genes.