Therapy switching in patients receiving long-acting opioids.

BACKGROUND Patterns of therapy switching in patients receiving long-acting opioids have not been well documented. OBJECTIVE To compare therapy switching among patients beginning treatment with controlled-release (CR) oxycodone, transdermal fentanyl, or CR morphine sulfate. METHODS Using a US healthcare claims database, we identified patients beginning treatment with CR oxycodone, transdermal fentanyl, or CR morphine sulfate between July 1, 1998, and December 31, 1999. We compiled claims for each patient for 6 months following therapy initiation and compared the incidence of therapy switching among the 3 groups. We also estimated total healthcare charges for patients who switched therapy versus those who did not. RESULTS We identified 1931, 668, and 449 patients beginning therapy with CR oxycodone, transdermal fentanyl, and CR morphine sulfate, respectively; 16.7%, 25.0%, and 35.9%, respectively, had cancer. For patients without cancer, rates of therapy switching at 6 months were 10.6% (CR oxycodone), 19.0% (transdermal fentanyl), and 26.0% (CR morphine sulfate); for those with cancer, rates were 23.8%, 24.6%, and 29.8%, respectively. Multivariate hazard ratios (vs CR morphine sulfate) for therapy switching in patients without cancer were 0.36 (95% CI, 0.27 to 0.47) for CR oxycodone and 0.69 (0.51 to 0.94) for transdermal fentanyl; for those with cancer, corresponding hazard ratios were 0.72 (0.50 to 1.03) and 0.76 (0.50 to 1.16). Total healthcare charges were significantly (p < 0.01) higher for patients who switched therapy than those who did not (23,965 US dollars vs 14,299 US dollars in pts. without cancer; 58,259 US dollars vs 39,618 US dollars for those with cancer). CONCLUSIONS Patients without cancer who receive CR oxycodone or transdermal fentanyl are less likely to switch therapy than those receiving CR morphine sulfate. Total healthcare charges are higher for patients who switch therapy.