UGT1A4 and Decreased liver function: These findings may explain the reduced glucuronidation of morphine (UGT2B7) [15], lamotrigine (UGT1A4, UGT2B7) [16], zidovudine (UGT2B7) [17], mycophenolic acid (UGT1A9, UGT2B7) [18], or oxazepam (UGT2B15) [19] in patients with liver dysfunction.