Individual differences in the sensitivity to fentanyl, a widely used opioid analgesic, can hamper effective pain treatment. The adrenergic system is reportedly involved in the mechanisms of pain and analgesia. Here, we focused on one of the adrenergic receptor genes, ADRB1, and analyzed the influence of single-nucleotide polymorphisms (SNPs) in the ADRB1 gene on individual differences in pain and analgesic sensitivity. We examined associations between pain and fentanyl sensitivity and the two SNPs, A145G and G1165C, in the human ADRB1 gene in 216 Japanese patients who underwent painful orofacial cosmetic surgery, including bone dissection. The patients who carried the A-allele of the A145G SNP were more sensitive to cold pressor– induced pain than those who did not carry this allele, especially in male patients. The analgesic effect was significantly less in females who carried the G-allele of the G1165C SNP than the females who did not carry the G-allele. The haplotype analysis revealed a significant decrease in 24-h postoperative fentanyl use in female 145A/1165C haplotype carriers. These results suggest that SNPs in the ADRB1 gene are associated with individual differences in pain and analgesic sensitivity, and analyzing these SNPs may promote personalized pain treatment in the future.
2013 The Japanese Pharmacological Society