A pooled analysis evaluating the efficacy and tolerability of tapentadol extended release for chronic, painful diabetic peripheral neuropathy.

BACKGROUND AND OBJECTIVE: Data from two similarly designed studies of tapentadol extended release (ER) for managing neuropathic pain associated with diabetic peripheral neuropathy (DPN; NCT00455520, NCT01041859) in adults were pooled for this analysis, allowing a detailed evaluation of efficacy in patient subgroups and secondary endpoints. METHODS: In each study, patients were titrated to their optimal dose of open-label tapentadol ER [100-250 mg twice daily (bid)] over 3 weeks. Patients with ≥1-point improvement in average pain intensity [11-point numerical rating scale (NRS)] were randomized (1:1) to receive placebo or tapentadol ER during a 12-week, double-blind maintenance period. RESULTS: Mean (standard deviation [SD]) changes in pain intensity from baseline to week 12 of maintenance in the placebo (n = 343) and tapentadol ER (n = 360) groups, respectively, were 1.28 (2.41) and 0.08 (1.87) [least squares mean difference (LSMD): -1.14 (95 % confidence interval [CI]: -1.435, -0.838); P < 0.001, in favour of tapentadol ER]. Significant between-group differences were also observed in changes from the start of the double-blind treatment period to the double-blind endpoint for the Short Form-36 physical functioning, role-physical, bodily pain, social functioning and role-emotional subscale and physical component summary scores, and the EuroQol 5-Dimension health status index (all P < 0.05, in favour of tapentadol ER). No clinically relevant differences were observed in the efficacy of tapentadol ER across patient subgroups divided by age, sex, race, opioid experience and pain intensity. Incidences of treatment-emergent adverse events were 56.0 % (192/343) with placebo and 74.7 % (269/360) with tapentadol ER during maintenance. CONCLUSION: Results of this pooled analysis indicate that tapentadol ER was effective for managing DPN-related pain, and provided consistent analgesic efficacy across different patient subgroups.

A randomized withdrawal, placebo-controlled study evaluating the efficacy and tolerability of tapentadol extended release in patients with chronic painful diabetic peripheral neuropathy.

OBJECTIVE: This study evaluated the efficacy and tolerability of tapentadol extended release (ER) for the management of chronic pain associated with diabetic peripheral neuropathy (DPN). RESEARCH DESIGN AND METHODS: Adults with moderate to severe DPN pain were titrated to tapentadol ER 100-250 mg bid during a 3-week open-label period; patients with ≥1-point reduction in pain intensity (11-point numerical rating scale) at end of titration were randomized to receive placebo or tapentadol ER (optimal dose from titration) for 12 weeks (double-blind, fixed-dose maintenance phase). The primary end point was mean change in average pain intensity from the start to week 12 (last observation carried forward [LOCF]) of the double-blind maintenance phase. RESULTS: A total of 358 patients completed the titration period; 318 patients (placebo, n = 152; tapentadol ER, n = 166) were randomized and received one or more doses of double-blind study medication. Mean (SD) pain intensity (observed case) was 7.33 (1.30) at the start and 4.16 (2.12) at week 3 of the open-label titration period (mean [SD] change, -3.22 [1.97]). The mean (SD) change in pain intensity (LOCF) from start of double-blind treatment to week 12 was as follows: placebo, 1.30 (2.43); tapentadol ER, 0.28 (2.04; least squares mean difference, -0.95 [95% CI -1.42 to -0.49]; P < 0.001). Treatment-emergent adverse events (≥10%) in the tapentadol ER group during the double-blind maintenance phase were nausea (21.1%) and vomiting (12.7%). CONCLUSIONS: Tapentadol ER (100-250 mg bid) was effective and well tolerated for the management of moderate to severe chronic pain associated with DPN.

A comparison among tapentadol tamper-resistant formulations (TRF) and OxyContin® (non-TRF) in prescription opioid abusers.

AIMS: To examine whether tamper-resistant formulations (TRFs) of tapentadol hydrochloride extended-release (ER) 50 mg (TAP50) and tapentadol hydrochloride 250 mg (TAP250) could be converted into forms amenable to intranasal (study 1) or intravenous abuse (study 2). DESIGN: Randomized, repeated-measures study designs were employed. A non-TRF of OxyContin® 40 mg (OXY40) served as a positive control. No drug was taken in either study. SETTING: The studies took place in an out-patient setting in New York, NY. PARTICIPANTS: Twenty-five experienced, healthy ER oxycodone abusers participated in each study. MEASUREMENTS: The primary outcome for study 1 was the percentage of participants who indicated that they would snort the tampered tablets, while the primary outcome for study 2 was the percentage yield of active drug in solution. Other descriptive variables, such as time spent manipulating the tablets, were also examined to characterize tampering behaviors more clearly. FINDINGS: Tampered TRF tablets were less desirable than the tampered OXY40 tablets. Few individuals were willing to snort the TRF particles (TAP50: 24%, TAP250: 16%; OXY40: 100% P < 0.001). There was less drug extracted from the TAP50 tablet than from the OXY40 tablet (3.52 versus 37.02%, P = 0.008), and no samples from the TAP250 tablets contained analyzable solutions of the drug. It took participants longer to tamper with the TAPs (study 1: TAP50 versus OXY40, P < 0.01; TAP250 versus OXY40, P < 0.01; study 2: TAP250 versus OXY40, P < 0.05). CONCLUSIONS: Tamper-resistant formulations of taptentadol (pain relief) tablets do not appear to be well-liked by individuals who tamper regularly with extended-release oxycodone tablets. Employing tamper-resistant technology may be a promising approach towards reducing the abuse potential of tapentadol extended-release.

Safety and efficacy of tapentadol ER in patients with painful diabetic peripheral neuropathy: results of a randomized-withdrawal, placebo-controlled trial.

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.

Efficacy and safety of tapentadol extended release for the management of chronic low back pain: results of a prospective, randomized, double-blind, placebo- and active-controlled Phase III study.

OBJECTIVE: To evaluate the efficacy and safety of tapentadol extended release (ER) for the management of moderate to severe chronic low back pain. RESEARCH DESIGN: Patients (N = 981) were randomized 1:1:1 to receive tapentadol ER 100 - 250 mg b.i.d., oxycodone HCl controlled release (CR) 20 - 50 mg b.i.d., or placebo over 15 weeks (3-week titration period, 12-week maintenance period). MAIN OUTCOME MEASURES: Efficacy was assessed as change from baseline in average pain intensity (11-point NRS) at week 12 of the maintenance period and throughout the maintenance period; last observation carried forward was used to impute missing pain scores. Adverse events (AEs) were monitored throughout the study. RESULTS: Tapentadol ER significantly reduced average pain intensity versus placebo at week 12 (least squares mean difference vs placebo [95% confidence interval], -0.8 [-1.22, -0.47]; p < 0.001) and throughout the maintenance period (-0.7 [-1.06,-0.35]; p < 0.001). Oxycodone CR significantly reduced average pain intensity versus placebo at week 12 (-0.9 [-1.24,-0.49]; p < 0.001) and throughout the maintenance period (-0.8 [-1.16,-0.46]; p < 0.001). Tapentadol ER was associated with a lower incidence of treatment-emergent AEs (TEAEs) than oxycodone CR. Gastrointestinal TEAEs, including constipation, nausea, and vomiting, were among the most commonly reported TEAEs (placebo, 26.3%; tapentadol ER, 43.7%; oxycodone CR, 61.9%). The odds of experiencing constipation or the composite of nausea and/or vomiting were significantly lower with tapentadol ER than with oxycodone CR (both p < 0.001). CONCLUSIONS: Tapentadol ER (100 - 250 mg b.i.d.) effectively relieved moderate to severe chronic low back pain over 15 weeks and had better gastrointestinal tolerability than oxycodone HCl CR (20 - 50 mg b.i.d.).

Dose conversion between tapentadol immediate and extended release for low back pain.

BACKGROUND: Tapentadol, a novel, centrally acting analgesic with 2 mechanisms of action (mu-opioid receptor agonism and norepinephrine reuptake inhibition), has been developed in an immediate-release (IR) and an extended-release (ER) formulation. Determination of the safety and equianalgesic ratios for conversion between formulations is important for physicians with patients taking tapentadol IR who may want to switch to tapentadol ER, or vice versa, for any reason. OBJECTIVES: To test whether the total daily dose (TDD) of tapentadol IR may be directly converted into a comparable TDD of tapentadol ER, and vice versa, with equivalent efficacy and comparable safety. STUDY DESIGN: Randomized, double-blind, 2-period (2 weeks each) crossover study. SETTING: Study centers (N = 13) in the United States. METHODS: Patients with moderate to severe chronic low back pain received tapentadol IR 50, 75, or 100 mg every 4 or 6 hours (maximum TDD, 500 mg) during the 3-week open-label period to identify an optimal, stable dose of tapentadol IR for each patient. Patients were then randomized in a 1:1 ratio to receive, during the first 2-week double-blind period, either the optimal dose of tapentadol IR identified during the open-label period or a TDD of tapentadol ER (100, 150, 200, or 250 mg bid) that was as close as possible to the TDD of tapentadol IR from the open-label period. During a subsequent, 2-week double-blind period, patients received whichever formulation was not received during the first double-blind period. The primary endpoint was the mean average daily pain intensity (on an 11-point numerical rating scale) during the last 3 days of each double-blind treatment period. If the 95% confidence intervals (CIs) of the least squares mean difference between formulations were within the range of -2 to 2, the formulations were considered equivalent. RESULTS: Of the 88 patients who were randomized, 72 completed both double-blind treatments, and 60 were included in the per-protocol analysis. The mean (standard deviation [SD]) pain intensity score decreased from 7.3 (1.19) pre-treatment to 4.2 (2.13) after 3 weeks of open-label treatment with tapentadol IR and remained constant throughout double-blind treatment (3.9 or 4.0 each week) for both formulations. The mean (SD) of the average pain intensity scores over the last 3 days of double-blind treatment was 3.9 (2.17) with tapentadol IR and 4.0 (2.29) with tapentadol ER, for an estimated difference of 0.1 (95% CI, -0.09 to 0.28). For both tapentadol IR and tapentadol ER, the median TDD administered was 300.0 mg, and acetaminophen was used by 39.5% and 45.2% of patients, respectively. The incidence of treatment-emergent adverse events during double-blind treatment was similar between the tapentadol IR and tapentadol ER groups. LIMITATIONS: Use of rescue medication theoretically could have influenced pain measurements, but in practice, pain measurements did not differ between treatments. CONCLUSIONS: Approximately equivalent TDDs of tapentadol IR and tapentadol ER provided equivalent analgesic efficacy for the relief of moderate to severe chronic low back pain and were similarly well tolerated, allowing for direct conversion between the 2 formulations. CLINICAL TRIAL REGISTRATION: NCT00594516.

EVALUATING KINSHIP OF NEWLY SETTLED JUVENILES WITHIN SOCIAL GROUPS OF THE CORAL REEF FISH ANTHIAS SQUAMIPINNIS.

It is conventionally assumed that eggs and/or larvae of most coral reef fishes are thoroughly mixed during a pelagic phase, so that juvenile recruits at any particular reef site represent a random sample of the reproductive products entering the local gene pool. However, a recent review of biological factors that might limit mixing raised the testable hypothesis that groups of genetically related individuals may sometimes persist through the pelagic phase and settle as sibling cohorts (Shapiro, 1983). Here we provide a critical genetic test of this hypothesis by examining allozyme variation in juvenile aggregations of the serranid reef fish, Anthias squamipinnis. Results demonstrate that juvenile cohorts within large social groups in Anthias are not composed exclusively or predominantly of siblings, but rather represent a random sample of progeny from many matings. Also included are considerations of allelic and genotypic criteria by which hypotheses about sibling assemblages might generally be evaluated.