Effect of CYP3A4 and CYP3A5 Polymorphism on Edema Incidence in Indonesian Amlodipine Users

Amlodipine, a calcium channel blocker, is recommended as a first-line treatment for hypertension in Indonesia. However, reports from several community health centers in Indonesia indicate that long-term use of amlodipine has led to side effects such as ankle edema in a significant percentage of patients. Genetic variations in drug metabolism in an individual's body may contribute to these side effects. This study investigates the association between CYP3A5*3 and CYP3A4*1G and the incidence of peripheral edema in Indonesian amlodipine patients. This cross-sectional, analytical, observational study involved 85 peripheral blood samples from hypertensive patients. The Tetra-primer Amplification Refractory Mutation System-Polymerase Chain Reaction (ARMS-PCR) method was used to identify variations in the CYP3A4*1G and CYP3A5*3 genes. The contingency coefficient analysis was conducted with IBM Statistic SPSS22 software to analyze the association of gene variants and the occurrence of peripheral edema. The incidence of edema in patients taking amlodipine occurred in 6 cases in individuals with the CYP3A4*1/*1G and CYP3A5*3/*3 genotype combination and in 3 cases in individuals with the CYP3A4*1/*1 and CYP3A5*3/3 genotype combination. However, with a p-value greater than 0.05 (p=0.536), the genotype variations did not significantly correlate with the incidence of peripheral edema. There is no association between CYP3A4*1G and CYP3A5*3 gene variation with an incidence of ankle edema in amlodipine-using patients.