The conversion ratio for opioid rotation from hydrocodone to other strong opioids in cancer patients.

Abstract

164 Background: Cancer pain is initially treated with intermediate strength analgesics such as hydrocodone and subsequently escalated to stronger opioids. There are no studies on the process of opioid rotation (OR) from hydrocodone to strong opioids in cancer patients. Our aim was to determine the conversion ratio (CR) for OR from hydrocodone to morphine equivalent daily dose (MEDD) in cancer outpatients. Methods: We reviewed records of 3,144 consecutive patient visits at our Supportive Care Center in 2011-12 for OR from hydrocodone to stronger opioids. Data regarding demographics, Edmonton Symptom Assessment Scale (ESAS), and MEDD were collected in patients who returned for follow up within 6 weeks. Linear regression analysis was used to estimate the CR between hydrocodone and MEDD. Successful OR was defined as 2-point or 30% reduction in the pain score and continuation of the new opioid at follow up. Results: 170/3,144 patients underwent OR from hydrocodone to stronger opioid. 72% were white, 56% male, and 81% had advanced cancer. The median time between OR and follow up was 21 days. 53% had a successful OR with significant improvement in the ESAS pain and symptom distress scores. In 100 patients with complete OR and no worsening of pain at follow up, the median CR (Q1-Q3) from hydrocodone to MEDD was 1.5 (0.9-2) and hydrocodone dose to MEDD correlation was.52 (P<0.0001). The correlation of CR with hydrocodone dose was -0.52 (P<0.0001). The median CR of hydrocodone to MEDD was 2 in patients receiving < 40mg of hydrocodone/day and 1 in patients receiving ≥ 40mg of hydrocodone/day (P<0.0001). The median conversion ratio of hydrocodone to morphine was 1.5 (n=44) and hydrocodone to oxycodone was 0.9 (n=24). Conclusions: Hydrocodone is 1.5-fold stronger than Morphine. The median conversion ratio from hydrocodone to MEDD varied according to hydrocodone dose/day. [Table: see text]