Analysis of Single Nucleotide Polymorphism A118g Gene Opioid Receptor Mu-1 (OPRM1) In Opioid Analgesic Patients in Indonesia Mara Imam Taufiq Siregar, Arie Utariani*, Hamzah, Elizeus Hanindito, Prananda Surya Airlangga and Retno Handajani Abstract Introduction: Opioid Receptor Mu-1 or Opioid Receptor Mu-1 (OPRM1) is a prime candidate for pharmacogenetic studies related