AAPM Abstract Roundup (Part 2)

Abstract #110A Day-to-Day Analysis of the Analgesic Efficacy of Milnacipran in the Treatment of FibromyalgiaAuthors: Datta A, MSc, Mease P, Palmer R, et al

Purpose: Fibromyalgia (FM) pain is characterized by day-to-day fluctuations in intensity. By assessing pain data recorded daily using e-diaries, the day-to-day effects of milnacipran on pain during two double-blind clinical trials were examined.

Results: Milnacipran-treated patients achieved ≥30% pain reduction in 47% (200 mg/day) and 46% (100 mg/day) of days during the 3-month period compared with 31% for placebo patients (P<.001, both doses) in Study 1, and 45% (200 mg/day) and 44% (100 mg/day) of days compared with 34% for placebo patients (P<.001, both doses) in Study 2. Similarly, milnacipran-treated patients achieved _50% pain reduction in a significantly greater proportion of days over the 3-month period than patients on placebo (Study 1: 30%, milnacipran 100 mg/day; 30%, milnacipran 200 mg/day; 17%, placebo; P<.001, both doses; Study 2: 28%, milnacipran 100 mg/day; 25%, milnacipran 200 mg/day; 18%, placebo; P<.01, both doses).

Funding: Supported by Forest Laboratories, Inc. and Cypress Bioscience, Inc.

Abstract #112Tolerability of Equivalent Doses of Tapentadol Immediate Release (IR) and Tapentadol Extended Release (ER) in a Crossover Study of Patients with Moderate to Severe Chronic Low Back PainAuthors: Etropolski M, Shapiro D, Okamoto A, et al

Purpose: The dose equivalence and ability for direct conversion between tapentadol IR and tapentadol ER were determined in patients with moderate-to-severe chronic low back pain.

Results: Mean (SD) average pain intensity decreased from 7.3(1.19) pre-treatment to 4.0(2.29) for tapentadol ER and 3.9(2.17) for tapentadol IR over the last 3 days of double-blind treatment (per-protocol, n=60); the least-squares mean difference (95% CI) of 0.1(−0.09,0.28) was within the pre-specified equivalence margin (—2,2). The most common TEAEs were dizziness, headache, somnolence, and nausea. Incidences of TEAEs during doubleblind treatment were similar for tapentadol ER (33.3%) and IR (34.6%); no TEAE was reported by _5% of patients with either formulation; incidences were lower than during open-label treatment because of the 21-day open-label exposure to tapentadol IR. Tolerability results were similar to previous studies.

Funding: Study supported by Johnson & Johnson Pharmaceutical Research & Development, L.L.C. and Grünenthal GmbH

Abstract #113Efficacy and Safety of Tapentadol ER for Diabetic Peripheral Neuropathic PainAuthors: Etropolski M, Shapiro D, Okamoto A, et al

Purpose: This study evaluated the efficacy and safety of tapentadol ER, a centrally acting analgesic with mu-opioid agonist and norepinephrine reuptake inhibitor activities, for the management of diabetic peripheral neuropathic (DPN) pain.

Results: During the open-label period, 588 patients received ≥1 dose of tapentadol ER; 389 patients entered the double-blind period and received ≥1 dose of study medication. Among patients who entered the double-blind period, mean (standard deviation) pain intensity decreased from 7.3 (1.43) to 3.5 (1.89) during open-label treatment. During the double-blind period, average pain intensity remained relatively constant in the tapentadol ER group and increased in severity in the placebo group (least-squares mean difference, —1.3 [95% confidence interval, –1.70, –0.92]; P<0.001). The most common reasons for discontinuation during double-blind treatment were adverse events with tapentadol ER (14.8%) and lack of efficacy with placebo (14.0%). The safety profile of tapentadol ER was consistent with previous observations.

Funding: Study supported by Johnson & Johnson Pharmaceutical Research & Development, L.L.C. and Grünenthal GmbH

Abstract #114Epidural Steroid Injection: A Retrospective Comparison of the Lumbar Interlaminar versus the Transforaminal Approach at the University of Arkansas Chronic Pain ClinicAuthors: Firnhaber-Burgos J, Keith C, Rosenbaum T

Purpose: We did a retrospective chart review analysis to compare the efficacy of fluoroscopic guidance translaminar versus transforaminal ESI six weeks after a single injection.

Results: The protocol was approved by the University of Arkansas for Medical Sciences IRB committee. A total of 45 patients’ charts were reviewed (transforaminal group: 20, interlaminar group: 25). Inclusion criteria: 1.Age 18-65. 2. Low back with radicular pain. 3. Pain more than two years. 4. No prior back surgery. 5. Patients were not involved in any litigation due to their current problem. Exclusion criteria: 1. Substance abuse. 2. Use of long-acting narcotics. 3. Presence of any neurological deficit. 4. Previous ESI. 5.Pregnancy. Visual analog score (VAS) was significantly reduced in both groups, but no difference was found between the tow approaches. Although rare, complications associated with transforaminal ESI include permanent paralysis, stroke, and death; although both techniques are equally effective we suggest the interlaminar as the safer and preferable approach. Further studies with a larger number of subjects are needed to confirm our results.

Abstract #115Outcomes in Osteoarthritis (OA): Analysis of Pooled Data from Randomized Placebo-controlled Clinical Trials of Duloxetine in Patients with Knee OAAuthors: Gaynor P, Hochberg M, Risser R, et al

Purpose: To better characterize the efficacy of duloxetine in OA of the knee by applying OARSI criteria. Each site’s ethics committee approved the protocol in accordance with principles of Declaration of Helsinki. This post-hoc analysis pooled data from two 13-week, double-blind, randomized, placebo-controlled clinical trials comparing duloxetine (60 to 120 mg/d) and placebo in patients with symptomatic radiographic OA of the knee.

Results: Baseline demographic and clinical characteristics of patients did not differ between the two treatment groups except for sex, with significantly fewer women in the duloxetine group (p=.02). Patients randomized to duloxetine were 33% more likely to experience an OMERACT-OARSI response compared to placebo (p_.001). Significantly more duloxetine-treated fulfilled criteria for MCII and achieved PASS, for both pain and function, respectively. More duloxetinetreated patients experienced TEAE than patients in the placebo group. Significantly more duloxetinetreated patients discontinued due to adverse events (p_.001). No deaths occurred during these studies.

Funding: Funded by Eli Lilly and Company