Despite the current OD epidemic, effective pharmacotherapies are grossly underutilized.47 Buprenorphine has emerged as an office-based treatment for OD, but in a Cochrane review methadone was more effective than buprenorphine when delivered at an adequate dosage.48 Overly conservative dosing undermines clinical effectiveness,49–51 although clinicians must also be careful to minimize the danger of doses that are too high for their patients.52 The initiation of methadone treatment is therefore particularly challenging. The dosage required varies widely, and there are no methods available at the start of treatment to predict the optimal dose for a particular patient.22 Similar patient-to-patient variability is also seen when opioids are used for pain control, and a substantial portion of this variance has been attributed to heritable factors.53
