RESUMEN
Aim: To evaluate the association between OPRK1 rs963549 and rs997917 and opioid use disorder (OUD) and related phenotypes. Methods: A sample of 208 individuals with (n = 100) and without (n = 108) OUD were enrolled. OPRK1 rs963549 and rs997917 were analyzed by PCR-RFLP. Craving, opioid withdrawal and the intensity of depressive and anxiety symptoms were measured by the appropriate scales. Results: OPRK1 rs963549 variation showed a trend of association with decreased opioid withdrawal. No significant associations were found between OPRK1 rs963549 and rs997917 polymorphisms and craving, depression or anxiety symptoms. Neither single OPRK1 SNPs nor OPRK1 haplotypes were associated with OUD. Conclusion: Our results could be useful for treatment failures of individuals who experience greater opioid withdrawal due to their OPRK1 rs963549 genotypes.