Factors affecting acceptability of titrated oxymorphone extended release in chronic low back pain - an individual patient analysis.
OBJECTIVE
To evaluate the influence of age, sex, and previous opioid experience on the likelihood of successfully titrating opioid-naive and experienced patients with chronic low back pain (CLBP) to an effective and well-tolerated dose of oxymorphone extended release (ER).


METHODS
Post hoc analysis of open-label titration phases of two enriched-enrollment randomized-withdrawal phase III trials in 575 adults with moderate-to-severe CLBP. Opioid-naive patients (n = 325) initiated oxymorphone ER at 10 mg/day (5 mg q12 h). Opioid-experienced patients (n = 250) initiated at a dose equianalgesic to their previous opioid and were allowed doses of 5 mg oxymorphone immediate-release rescue medication every 4-6 h, as needed. Oxymorphone ER was gradually titrated to a dose that reduced pain to <or=40 mm on a 100 mm visual analog scale.


BACKGROUND
NCT00225797, NCT00226421.


METHODS
Number of patients reaching stabilized oxymorphone ER dose, reasons for treatment discontinuation in patients not reaching stabilized dose.


RESULTS
Open-label titration was successful in 61% (348/575) of patients, and similar proportions of men (63%) and women (59%) and opioid-naive (63%) and experienced (57%) patients. Patients aged >or=65 years were less likely than patients aged <65 years to complete titration (45 vs. 63%; p = 0.002; 95% CI, -0.30 to -0.06) and more likely to discontinue owing to adverse events (40 vs. 15%; p < 0.001; 95% CI, 0.14-0.36). Oxycodone-experienced patients were less likely than hydrocodone-experienced patients to complete titration (46 vs. 62%, p = 0.03; 95% CI,-0.30 to -0.02). Among successfully titrated patients, pain decreased regardless of prior opioid therapy, sex, or age.


CONCLUSIONS
Most patients with CLBP were titrated to an effective, generally well-tolerated oxymorphone ER dose. Older patients and those converted from oxycodone may require more gradual titration. A study limitation is that patients initiated oxymorphone ER to comply with protocol, whereas treatment failure typically motivates opioid initiation or switching in clinical practice.
Feasterville Family Health Care Center, Feasterville, PA 19053, USA. afudala@amh.org
John H
JH
Peniston
Qinfang
Q
Xiang
Errol M
EM
Gould
D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D002908:Chronic Disease; D017326:Clinical Trials, Phase III as Topic; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D004091:Hydromorphone / Q000008:administration & dosage / Q000009:adverse effects; D017116:Low Back Pain / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010098:Oxycodone / Q000008:administration & dosage / Q000009:adverse effects; D010111:Oxymorphone / Q000008:administration & dosage* / Q000009:adverse effects; D010147:Pain Measurement; D010342:Patient Acceptance of Health Care; D016032:Randomized Controlled Trials as Topic; D013375:Substance Withdrawal Syndrome / Q000517:prevention & control; D016896:Treatment Outcome
D000701:Analgesics, Opioid; D003692:Delayed-Action Preparations; D010111:Oxymorphone; D010098:Oxycodone; D004091:Hydromorphone