Warfarin maintenance dose associated with genetic polymorphisms of CYP2C9.

BACKGROUND

Cytochrome P450 2C9 () gene polymorphisms alters the required warfarin dose in patients, due to pharmacogenetic events. This study aimed to identify the frequency of the allele polymorphic variants *2 and *3, and the association of these allelic variants with warfarin dosage in the population of the west Azerbaijan province in Iran.

METHODS

One hundred and seventy patients receiving warfarin were examined to evaluate the genotype frequency of common polymorphisms. Genotype analysis for *2 and *3 polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. To assess if the dosage is different between genotypes we used one-way analysis of variance (ANOVA).

RESULTS

Frequency of the two variants in studied subjects was 12 % for *2 and 25.8 % for *3. Comparison of the warfarin daily maintenance dose between genotype groups showed that the daily mean dose of warfarin in patients who have homozygous wild-type genotype for (1/1) was 5.26 ± 2.32 mg, which was significantly higher compared to 1/2, 1/3 (3.57 ± 2.25 mg, p <0.001) and 2/2, 2/3 and 3/3 patients (3.76 ± 2.4 mg, p =0.024). Further analysis revealed that the allelic frequency of polymorphisms in the study population was similar to that of the Turkish population.

CONCLUSIONS

Due to the relatively high frequency of polymorphisms in the study population, the clinicians should become aware of these results to reduce the risk of hemorrhage when prescribing warfarin. HIPPOKRATIA 2017, 21(2): 93-96.