OBJECTIVE: Painful diabetic peripheral neuropathy (DPN) may not be adequately managed with available therapeutic options. This phase III, randomized-withdrawal, placebo-controlled trial evaluated the safety and efficacy of tapentadol extended release (ER) for relieving painful DPN.
RESEARCH DESIGN AND METHODS: Patients (n = 588) with at least a 3-month history of opioid and/or non-opioid analgesic use for DPN, dissatisfaction with current treatment, and an average pain intensity score of at least 5 on an 11-point numerical rating scale (NRS; 0 = 'no pain,' 10 = 'pain as bad as you can imagine') were titrated to an optimal dose of tapentadol ER (100-250 mg bid) during a 3-week open-label phase. Subsequently, patients (n = 395) with at least a 1-point reduction in pain intensity were randomized 1:1 to receive placebo or the optimal fixed dose of tapentadol ER determined during the open-label phase for a 12-week double-blind phase. Clinical trial registration: NCT00455520.
MAIN OUTCOME MEASURES: The primary efficacy outcome was the change in average pain intensity from randomization, determined by twice-daily NRS measurements. Safety was assessed throughout the study. Results: The least-squares mean difference between groups in the change in average pain intensity from the start of double-blind treatment to week 12 was -1.3 (95% confidence interval, -1.70 to -0.92; p < 0.001, tapentadol ER vs. placebo). A total of 60.5% (356/588) of patients reported at least a 30% improvement in pain intensity from the start to the end of the open-label titration phase; of the patients who were randomized to tapentadol ER, 53.6% (105/196) reported at least a 30% improvement from pre-titration to week 12 of the double-blind phase. The most common treatment-emergent adverse events that occurred during double-blind treatment with tapentadol ER included nausea, anxiety, diarrhea, and dizziness. Potential limitations of this study are related to the enriched enrollment randomized-withdrawal trial design, which may result in a more homogeneous patient population during double-blind treatment and may present a risk of unblinding because of changes in side effects from the open-label to the double-blind phase.
CONCLUSIONS: Compared with placebo, tapentadol ER 100-250 mg bid provided a statistically significant difference in the maintenance of a clinically important improvement in pain 1 , 2 and was well-tolerated by patients with painful DPN.
UNLABELLED: Many studies have demonstrated that low heart rate variability (HRV) is a risk for high mortality and morbidity in patients with cardiovascular diseases. The primary purpose of the study was to evaluate whether pregabalin improves HRV in patients with diabetes and painful peripheral neuropathy. Resting heart rates were collected by using the LifeShirt System, developed by VivoMetrics (Ventura, Calif), at baseline and at the end of a 4-week intervention of pregabalin or placebo in patients with painful diabetic peripheral neuropathy. Heart rate variability analysis was performed on the collected R-R intervals using the Vivo- VMLA-036-00 3 Logic of the LifeShirt system. Of the 40 patients enrolled in the study, 70% completed the end of 4-week assessments (n = 15 in pregabalin and n = 14 in placebo). Compared with placebo, pregabalin treatment resulted in significant improvement in HRV measured by frequency domain analysis, that is, a reduction in low frequency-high frequency ratio (-1.30 ± 2.89 vs 0.37 ± 0.33, P = 0.03) and power of normalized low frequency (-0.049 ± 0.092 vs 0.0066 ± 0.023, P = 0.02), as well as an increase in power of normalized high frequency (0.039 ± 0.094 vs -0.038 ± 0.066, P = 0.02). Furthermore, pregabalin resulted in greater reduction of pain and symptoms of anxiety and greater improvement of quality of life. The improvement of HRV measures were not correlated with change of those measures. In conclusion, 4-week pregabalin treatment improved HRV in patients with painful diabetic peripheral neuropathy.
TRIAL REGISTRATION: NCT00573261 (clinicaltrials.gov).
<b>OBJECTIVE: </b>To assess the efficacy of Sativex, a cannabis-based medicinal extract, as adjuvant treatment in painful diabetic peripheral neuropathy (DPN).<b>RESEARCH DESIGN AND METHODS: </b>In this randomized controlled trial, 30 subjects with painful DPN received daily Sativex or placebo. The primary outcome measure was change in mean daily pain scores, and secondary outcome measures included quality-of-life assessments.<b>RESULTS: </b>There was significant improvement in pain scores in both groups, but mean change between groups was not significant. There were no significant differences in secondary outcome measures. Patients with depression had significantly greater baseline pain scores that improved regardless of intervention.<b>CONCLUSIONS: </b>This first-ever trial assessing the efficacy of cannabis has shown it to be no more efficacious than placebo in painful DPN. Depression was a major confounder and may have important implications for future trials on painful DPN.
BACKGROUND: Duloxetine, a selective serotonin and noradrenaline reuptake inhibitor, has been shown to be effective in treatment of diabetic peripheral neuropathic pain and approved for the management of patients with diabetic peripheral neuropathic pain (DPNP) in the United States, European Union, and many other countries. This study assessed the efficacy and safety of duloxetine in Chinese patients with diabetic peripheral neuropathic pain.
METHODS: This double-blind, randomized, placebo-controlled, flexible-dose study treated adult patients with diabetic peripheral neuropathic pain and baseline Brief Pain Inventory (BPI) 24-hour average pain severity ratings ≥ 4 with duloxetine 60 mg to 120 mg once daily or placebo for 12 weeks. Dose adjustments of duloxetine or matching placebo were based upon investigator's judgment of clinical response. Change from baseline to endpoint in BPI average pain was the primary efficacy outcome. Secondary outcome measures included BPI-severity and -Interference, Patient Global Impression of Improvement, Clinical Global Impressions of Severity, EuroQol: 5 Dimensions, Athens Insomnia Scale, and safety measures.
RESULTS: Of 215 patients randomized, 88.4% and 82.1% of patients in placebo and duloxetine groups, respectively, completed the study. Mean change from baseline to endpoint in BPI average pain was not statistically different between the treatment groups (P = 0.124). Duloxetine- treated patients showed significantly greater pain reduction compared with those in placebo group at weeks 1, 2, and 4 (P = 0.004, P = 0.009, and P = 0.006, respectively), but not at weeks 8 (P = 0.125) and 12 (P = 0.107). Duloxetine-treated patients experienced statistically significant improvement in Patient Global Impression of Improvement, Clinical Global Impression of Severity, area under the curve for pain relief, BPI-severity pain right now, and BPI-interference walking ability. Patients treated with duloxetine 120 mg once daily showed significantly greater pain reduction on the Brief Pain Inventory average pain score relative to placebo. Duloxetine-treated patients reported nausea, somnolence, anorexia, and dysuria significantly more than placebo.
CONCLUSIONS: Although the primary study endpoint was not achieved, the overall observed response pattern suggests the efficacy of duloxetine in the treatment of Chinese patients with diabetic peripheral neuropathic pain. The safety profile for duloxetine is similar to that reported in other global trials.
OBJECTIVES: The aims of this multicenter, randomized, placebo-controlled, double-blind trial were to confirm the efficacy of lacosamide at a daily dose of 400 mg/d and to explore the efficacy, safety, and tolerability of lacosamide 200 mg/d and 600 mg/d in the treatment of painful diabetic neuropathy. METHODS: The trial consisted of a 2-week run-in period, a 6-week titration phase, and a 12-week maintenance phase, during which patients received placebo or fixed doses of lacosamide 200, 400, or 600 mg/d. No back titration was allowed during the trial. The primary efficacy criterion was the change in Likert pain score from baseline to the average over the last 4 weeks of the maintenance phase in the intent-to-treat population. RESULTS: The lacosamide 400 mg/d group demonstrated statistically significant improvement in Likert pain score over placebo for the primary efficacy measure. At the end of treatment, 58% of patients in the lacosamide 400 mg/d treatment group achieved at least a 2-point or 30% reduction in Likert pain score, compared with 46% of placebo-treated patients. The lacosamide 200 mg/d group separated from placebo, but failed to show statistical significance for any of the primary or secondary outcome measures. The lacosamide 600 mg/d group was significantly more efficacious than placebo in the observed cases but not in the intent-to-treat population. This was probably secondary to a relatively high-premature withdrawal rate due to adverse events that occurred during the titration phase in that group. Overall lacosamide at daily doses of 200 to 400 mg was well tolerated, with 8% of patients discontinuing due to an adverse event from the 200 mg/d group and 23% from the 400 mg/d group compared with 9% in the placebo group. Discontinuations due to adverse events were highest in the 600 mg/d group (40%). The most common adverse events consisted of dizziness, nausea, tremor, headache, and fatigue. Somnolence, cognitive and behavioral side effects, weight change, and edema were notably low. DISCUSSION: Safety and efficacy analyses indicated that lacosamide 400 mg/d provided an optimal balance between efficacy and side effects in patients with painful diabetic neuropathy.
The efficacy and tolerability of oral lacosamide (200, 400, and 600 mg/day) was evaluated in patients with painful diabetic neuropathy in a double-blind, randomized, placebo-controlled trial. The primary target dose to be confirmed was lacosamide 400 mg/day. Efficacy was assessed by changes in pain scale scores from baseline, with changes over the last 4 weeks of the 12-week maintenance period regarded as the primary endpoint. Endpoint reductions in mean pain score were higher with all doses of lacosamide, reaching the level of significance with 400 mg/day (P = .05). Over the treatment period (titration + maintenance), pain relief was significantly higher than placebo with lacosamide 400 (P = .02) and 600 mg/day (P = .03). Lacosamide had an early-onset effect with significant reductions over placebo during the titration period. Nonparametric and mixed-model analysis approaches gave similar results, supporting significant efficacy at 400 mg/day. Secondary criteria such as Patient's Global Impression of Change, responder rates, and pain-free days provided additional support. Adverse events included dizziness, nausea, and headache. Incidence of cognitive and behavioral adverse events was low. This trial suggests that lacosamide has beneficial effects and may be a suitable treatment option for patients with diabetic neuropathic pain. PERSPECTIVE: This study presents efficacy and safety results of a phase 3, double-blind, placebo-controlled trial of the anticonvulsant drug lacosamide in patients with painful diabetic neuropathy. Lacosamide treatment at a dose of 400 mg/day reduced diabetic neuropathic pain with a favorable safety and tolerability profile that may be suitable for patients with diabetes.
Painful diabetic peripheral neuropathy (DPN) may not be adequately managed with available therapeutic options. This phase III, randomized-withdrawal, placebo-controlled trial evaluated the safety and efficacy of tapentadol extended release (ER) for relieving painful DPN.
RESEARCH DESIGN AND METHODS:
Patients (n = 588) with at least a 3-month history of opioid and/or non-opioid analgesic use for DPN, dissatisfaction with current treatment, and an average pain intensity score of at least 5 on an 11-point numerical rating scale (NRS; 0 = 'no pain,' 10 = 'pain as bad as you can imagine') were titrated to an optimal dose of tapentadol ER (100-250 mg bid) during a 3-week open-label phase. Subsequently, patients (n = 395) with at least a 1-point reduction in pain intensity were randomized 1:1 to receive placebo or the optimal fixed dose of tapentadol ER determined during the open-label phase for a 12-week double-blind phase. Clinical trial registration: NCT00455520.
MAIN OUTCOME MEASURES:
The primary efficacy outcome was the change in average pain intensity from randomization, determined by twice-daily NRS measurements. Safety was assessed throughout the study. Results: The least-squares mean difference between groups in the change in average pain intensity from the start of double-blind treatment to week 12 was -1.3 (95% confidence interval, -1.70 to -0.92; p < 0.001, tapentadol ER vs. placebo). A total of 60.5% (356/588) of patients reported at least a 30% improvement in pain intensity from the start to the end of the open-label titration phase; of the patients who were randomized to tapentadol ER, 53.6% (105/196) reported at least a 30% improvement from pre-titration to week 12 of the double-blind phase. The most common treatment-emergent adverse events that occurred during double-blind treatment with tapentadol ER included nausea, anxiety, diarrhea, and dizziness. Potential limitations of this study are related to the enriched enrollment randomized-withdrawal trial design, which may result in a more homogeneous patient population during double-blind treatment and may present a risk of unblinding because of changes in side effects from the open-label to the double-blind phase.
CONCLUSIONS:
Compared with placebo, tapentadol ER 100-250 mg bid provided a statistically significant difference in the maintenance of a clinically important improvement in pain 1 , 2 and was well-tolerated by patients with painful DPN.
