Brief Report: Is once daily enough? Assessing the impact of timing of methadone dose on pain sensitivity via quantitative sensory testing in persons with opioid use disorder.

BACKGROUND AND

OBJECTIVES

Once-daily methadone dosing for opioid use disorder (OUD) may leave periods of inadequate analgesia. We tested whether experimental pain sensitivity differs across the inter-dose interval.

METHODS

Twenty-five adults (52% female, 43.12 years old) with OUD receiving stable once-daily methadone completed thermal quantitative sensory testing at early post-dose and pre-dose.

RESULTS

Heat pain threshold (MD -3.75°C; g = -0.78; p < .001) and tolerance (MD -0.92°C; g = -0.49; p = .018) were lower at pre-dose. Temporal summation and conditioned pain modulation did not differ.

DISCUSSION AND

CONCLUSIONS

Pain sensitivity increased pre-dose, consistent with a hyperalgesic window.

SCIENTIFIC SIGNIFICANCE: Preliminary experimental evidence that once-daily methadone may contribute to cyclical hyperalgesia in persons with OUD.