Opioid prescription underfilling among retail pharmacies

Prescription opioid abuse is a major public health problem in the United States. Physicians who prescribe opioid analgesics are sometimes confronted with patients who request early refills, claiming that they have been "shorted" by their pharmacy. While a substantial differential diagnosis exists for apparent opioid overuse, the underfilling of opioid prescriptions at the level of retail pharmacies has not yet been systematically investigated.

The goals of the present study were to: 1) determine the incidence and magnitude of opioid prescription underfilling among retail pharmacies in Northeast Florida and 2) to compare the rates of under- and overfilling with noncontrolled substance prescription controls.

Patients receiving opioid prescriptions were recruited for this study during routine primary care office visits. These patients, blinded to the study goals, filled their prescriptions, and returned to the clinic with unopened medication bag(s) for dosage unit counts.

One hundred and twenty-one patients filled 134 opioid prescriptions from 103 unique pharmacies. Dosage unit counts revealed three slight opioid prescription underfills (1-3 dosage units) and three slight opioid prescription overfills (1-3 dosage units). We found no statistically significant differences between opioids and noncontrolled substance controls with regard to prescription underfills.

There was no evidence supporting patients' claims of significant opioid analgesic underfilling by retail pharmacies. Patients who repeatedly report medication shortages should be evaluated for opioid use disorders.