Consider ER oxymorphone in patients with chronic low back pain, comorbidities

In patients with chronic low back pain (CLBP) with comorbidities such as hypertension, diabetes, and cardiovascular disease (CVD), extended-release oxymorphone (Opana ER, Endo Pharmaceuticals) may be a safe and effective alternative, according to a study presented at the annual meeting of the American Academy of Pain Medicine, National Harbor, Md.

“When the presence of hypertension, diabetes, or cardiovascular disease is unfavorable to the risk-benefit considerations of other treatment options, oxymorphone extended-release may be an appropriate alternative," said John Peniston, DO, lead author, Feasterville Family Health Care Center, Feasterville, Pa.

A total of 575 patients were included in this post-hoc, subpopulation analysis of 2 randomized trials comparing oxymorphone ER with placebo in opioid-experienced and opioid-naïve patients with CLBP. In all, 35.5% of patients were hypertensive, 11.3% diabetic, and 13.9% had CVD.

During the open-label titration period (≤1 month), opioid-naïve patients initiated treatment with oxymorphone ER (5 mg) every 12 hours; opioid-experienced patients began treatment at the dose calculated to be equivalent to the patient’s current opioid therapy based on established dose conversion tables. Patients were titrated in increments of 5 mg to 10 mg every 12 hours every 3 to 7 days to a stabilized dose at which pain intensity was ≤40 mm according to the 100-mm Visual Analog Scale (VAS) for 3 or more of 5 consecutive days.

During this titration period, the incidence of ≥1 adverse events was similar in populations with and without hypertension (69.1% vs 69.3%, respectively), diabetes (73.8% vs. 68.6%), and CVD (73.8% vs 68.5%). Serious adverse events occurred in similar proportions of patients with or without hypertension (4 vs 3, respectively), diabetes (4 vs 3), and CVD (3 vs 4).

Mean VAS pain intensity declined significantly compared with baseline in all patients, from 69.8 at screening to 20.7 at baseline. Similar baseline VAS pain ratings were seen in patients with and without hypertension (20.8 and 20.4, respectively), diabetes (20.5 and 25.5), and CVD (18.4 and 21.3).

During the 12-week double-blind treatment period, patients received either placebo or continued treatment with oxymorphone ER at their stabilized dose. Oxymorphone immediate-release (5 mg every 4 to 6 hours as needed) was permitted as rescue medication during the first 4 days of treatment after which the maximum allowed dose was 10 mg/d.

Adverse events were more common with oxymorphone ER compared with placebo (52.6% vs. 41.0%, respectively). Nausea, constipation, headache, diarrhea, vomiting, and dizziness were the most common. Serious adverse events occurred in 4 patients treated with oxymorphone ER and 3 treated with placebo.

Similar small increases in mean VAS pain intensity from baseline to final visit in the oxymorphone ER treatment group were seen in patients with and without hypertension (9.8 vs 9.6, respectively), diabetes (13.3 vs 9.2), and CVD (13.0 vs 9.2) during the treatment period. Similar substantial increases in VAS pain intensity from baseline to final visit in the placebo group were observed in patients with and without hypertension (27.9 vs 28.4, respectively), diabetes (26.6 vs 28.4), and CVD (30.3 vs 28.0).

This study was funded by Endo Pharmaceuticals Inc.