What we are studying
There is no standard or accepted method in the literature for calculating average daily milligrams of morphine equivalents (MME). MMEs are a way to standardize across opioids of different potencies in epidemiology studies. In particular, overlapping prescriptions change the picture of MME if they are not accounted for properly.
There is a belief that 90 MME/day is a threshold for overdose risk in patients treated with opioids, perpetuated by the CDC Guideline for Prescribing Opioids for Chronic Pain. However, the Food and Drug Administration has pointed out that there is actually a gradient of risk and the concept of a 90 MME/day threshold is an artifact of how studies measured opioid use.
Consider the following scenario:
A patient receives 30 mg extended-release oxycodone twice a day for around-the-clock pain for 30 days (60 tab- 43 lets), and one 5 mg oxycodone twice a day as needed for breakthrough pain for 7 days (14 tablets). Both prescriptions are dispensed on the first day of a 30-day month, with no subsequent dispensing. Assume 1.5 as the conversion factor for oxycodone-to-morphine. Alarmingly, for this simple scenario, 4 definitional 49 variants return daily MME inconsistently: 31.2mg, 75.8mg, 93.5mg, 105mg per day. Are any of these correct?