Abuse deterrence testing: A dose ratio escalation study examining naloxone coadministered with intravenous hydromorphone in non-treatment-seeking, opioid-dependent drug users.

OBJECTIVE: To assess the reduction in intravenous (IV) abuse potential of hydromorphone from different dose ratio combinations with naloxone in opioid-dependent drug users. DESIGN: Randomized, blinded, dose ratio escalation study. SETTING: Single center. PARTICIPANTS: Following conversion to a stable IV dose of hydromorphone, 12 non-treatment-seeking, opioid-dependent subjects were randomly assigned and received at least one dose of study drug; seven subjects received all five study treatments. Five subjects withdrew early from the treatment phase: adverse events (2) and participant decision (3). INTERVENTIONS: Participants underwent a dose-selection phase to stabilize on an individualized hydromorphone dose. Stable subjects were dosed intravenously on 5 consecutive days. The dose received was one of five hydromorphone/naloxone dose ratios that included the combination of hydromorphone and placebo naloxone. Hydromorphone/naloxone treatment always involved increasing dose ratios of naloxone (8:1, 6:1, 4:1, and 2:1) with the hydromorphone-placebo naloxone treatment randomly assigned within the sequence of dose ratios. MAIN OUTCOME MEASURES: Drug Liking visual analog scale (VAS), Objective Opioid Withdrawal Scale (OOWS) and Subjective Opioid Withdrawal Scale (SOWS). RESULTS: Hydromorphone/naloxone placebo produced subjective effects typical of opioid administration, while hydromorphone/naloxone dose ratios were associated with significant increases in SOWS and OOWS scores (p < 0.05). Compared with hydromoprophone/naloxone placebo, naloxone reduced the effects of hydromorphone on most measures, including Drug Liking VAS, the antagonism was greatest for the 4:1 and 2:1 ratios. CONCLUSIONS: This study was an ethical investigation of the abuse deterrence potential of four hydromorphone/naloxone dose ratios. The IV coadministration of commercially available IV solutions of hydromorphone and naloxone in 4:1 and 2:1 ratios had statistically greater reductions of abuse-related opioid effects and triggers of withdrawal symptoms and there was a convergence of subjective and objective pharmacodynamic results and safety findings. An oral modified-release product, developed with a 2:1 hydromorphone/naloxone ratio, may have important public health benefits by reducing high-risk, IV abuse of prescription opioids, while providing pain relief when ingested orally and used in accordance with the Product Monograph.

The Pain and Sleep Questionnaire three-item index (PSQ-3): a reliable and valid measure of the impact of pain on sleep in chronic nonmalignant pain of various etiologies.

BACKGROUND: Sleep disturbance is among the more common complaints reported by chronic pain patients. Because pain-related sleep disturbance may serve as a marker for the assessment of responses to treatment for chronic pain, inclusion of a measure designed to assess the impact of pain on sleep in clinical trial protocols is important, if not necessary. Measures typically used for this purpose lack scales specifically designed for the assessment of the impact of pain on sleep or are based on a single item. Single-item scales lack reliability and, therefore, validity. OBJECTIVES: To investigate the psychometric properties of the five-item Pain and Sleep Questionnaire (PSQ) Index, which is embedded in the eight-item inventory, by applying an accepted methodology using retrospective analyses in controlled clinical trials in which the measure had been administered among patients with chronic nonmalignant pain. METHODS: Data were pooled from nine independent, single-site, double-blind, randomized placebo-controlled clinical trials conducted over a period of approximately 10 years, the majority of which were cross-over designs. A cross-validation approach was adopted with exploratory and confirmatory factor analyses conducted to evaluate the underlying structure and dimensionality of the measure. Internal consistency reliability was evaluated using Cronbach's alpha coefficient. Mean score differences were used to assess the ability of the index to detect important treatment changes. Correlation coefficients were calculated between index scores and scores from other health-related outcome measures to evaluate the criterion validity of the index. Finally, predictive validity was assessed using multiple regression analyses. RESULTS: Pooling the data resulted in a sample of 605 patients (65.5% female; mean age 55.7 years). Findings suggested a revised three-item PSQ Index (PSQ-3). The PSQ-3 demonstrated high internal consistency across samples (ranging from 0.82 to 0.93) and was sensitive to detecting meaningful treatment effects within different chronic pain categories. Moderate to strong correlations (r>0.40) between the PSQ-3 and other health-related outcome measures provided preliminary evidence for criterion-related validity. Results of multiple regression analyses demonstrated that the PSQ-3 accounted for between 29% and 40% of the variance in scores from other health-related outcome measures. CONCLUSIONS: Results support the scoring of a revised three-item index for the assessment of the impact of pain on sleep. The revised index demonstrated acceptable levels of internal consistency and preliminary support for the structural, criterion-related and predictive validity of the index was achieved.

Buprenorphine transdermal system in adults with chronic low back pain: a randomized, double-blind, placebo-controlled crossover study, followed by an open-label extension phase.

BACKGROUND: Buprenorphine is a mixed-activity, partial mu-opioid agonist. Its lipid solubility makes it well suited for transdermal administration. OBJECTIVE: This study assessed the efficacy and safety profile of a 7-day buprenorphine transdermal system (BTDS) in adult (age >18 years) patients with moderate to severe chronic low back pain previously treated with > or =1 tablet daily of an opioid analgesic. METHODS: This was a randomized, double-blind, placebo-controlled crossover study, followed by an open-label extension phase. After a 2- to 7-day washout of previous opioid therapy, eligible patients were randomized to receive BTDS 10 microg/h or matching placebo patches. The dose was titrated weekly using 10- and 20-microg/h patches (maximum, 40 microg/h) based on efficacy and tolerability. After 4 weeks, patients crossed over to the alternative treatment for another 4 weeks. Patients who completed the double-blind study were eligible to enter the 6-month open-label phase. Rescue analgesia was provided as acetaminophen 325 mg to be taken as 1 or 2 tablets every 4 to 6 hours as needed. The primary outcome assessments were daily pain intensity, measured on a 100-mm visual analog scale (VAS), from no pain to excruciating pain, and a 5-point ordinal scale, from 0 = none to 4 = excruciating. Secondary outcome assessments included the Pain and Sleep Questionnaire (100-mm VAS, from never to always), Pain Disability Index (ordinal scale, from 0 = no disability to 11 = total disability), Quebec Back Pain Disability Scale (categorical scale, from 0 = no difficulty to 5 = unable to do), and the 36-item Short Form Health Survey (SF-36). Patients and investigators assessed overall treatment effectiveness at the end of each phase; they assessed treatment preference at the end of double-blind treatment. After implementation of a precautionary amendment, the QTc interval was measured 3 to 4 days after randomization and after any dose adjustment. All assessments performed during the double-blind phase were also performed every 2 months during the open-label extension. Adverse events were collected by non-directed questioning throughout the study. RESULTS: Of 78 randomized patients, 52 (66.7%) completed at least 2 consecutive weeks of treatment in each study phase without major protocol violations (per-protocol [PP] population: 32 women, 20 men; mean [SD] age, 51.3 [11.4] years; mean weight, 85.5 [19.5] kg; 94% white, 4% black, 2% other). The mean (SD) dose of study medication during the last week of treatment was 29.8 (12.1) microg/h for BTDS and 32.9 (10.7) microg/h for placebo (P = NS). During the last week of treatment, BTDS was associated with significantly lower mean (SD) pain intensity scores compared with placebo on both the VAS (45.3 [21.3] vs 53.1 [24.3] mm, respectively; P = 0.022) and the 5-point ordinal scale (1.9 [0.7] vs 2.2 [0.8]; P = 0.044). The overall Pain and Sleep score was significantly lower with BTDS than with placebo (177.6 [125.5] vs 232.9 [131.9]; P = 0.027). There were no treatment differences on the Pain Disability Index, Quebec Back Pain Disability Scale, or SF-36; however, BTDS was associated with significant improvements compared with placebo on 2 individual Quebec Back Pain Disability Scale items (get out of bed: P = 0.042; sit in a chair for several hours: P = 0.022). Of the 48 patients/physicians in the PP population who rated the effectiveness of treatment, 64.6% of patients (n = 31) rated BTDS moderately or highly effective, as did 62.5% of investigators (n = 30). Among the 50 patients in the PP population who answered the preference question, 66.0% of patients (n = 33) preferred the phase in which they received BTDS and 24.0% (n = 12) preferred the phase in which they received placebo (P = 0.001), with the remainder having no preference; among investigators, 60.0% (n = 30) and 28.0% (n = 14) preferred the BTDS and placebo phases, respectively (P = 0.008), with the remainder having no preference. The mean placebo-adjusted change from baseline in the QTc interval ranged from -0.8 to +3.8 milliseconds (P = NS). BTDS treatment was associated with a significantly higher frequency of nausea (P < 0.001), dizziness (P < 0.001), vomiting (P = 0.008), somnolence (P = 0.020), and dry mouth (P = 0.003), but not constipation. Of the 49 patients completing 8 weeks of double-blind treatment, 40 (81.6%) entered the 6-month, open-label extension study and 27 completed it. Improvements in pain scores achieved during the double-blind phase were maintained in these patients. CONCLUSIONS: In the 8-week, double-blind portion of this study, BTDS 10 to 40 microg/h was effective compared with placebo in the management of chronic, moderate to severe low back pain in patients who had previously received opioids. The improvements in pain scores were sustained throughout the 6-month, open-label extension. (Current Controlled Trials identification number: ISRCTN 06013881).

Comparative bioavailability of single-dose methylphenidate from a multilayer-release bead formulation and an osmotic system: a two-way crossover study in healthy young adults.

OBJECTIVE: This study was conducted to compare plasma levels of methylphenidate over time with single doses of a multilayer-release (MLR) bead formulation and an osmotic, controlled-release oral delivery system (OROS) of methylphenidate in young adults. METHODS: This was a randomized, 2-way crossover study in which healthy, nonsmoking young adults (age 18-25 years) were randomized to receive methylphenidate MLR 20 mg QD or OROS methylphenidate 18 mg QD, with a 7-day washout between treatments. Plasma samples were collected before dosing and at 0.25, 0.5, 0.75, 1, 1.25, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8, 10, 12, 14, 16, and 24 hours after dosing. Analysis of plasma samples was conducted by high-performance liquid chromatography with tandem mass-spectrometry detection. Adverse events were monitored by spontaneous reports, laboratory and biochemistry tests, urinalysis, and physical examinations conducted at screening and at the end of the study. RESULTS: Of the 24 subjects originally enrolled, 3 discontinued for personal reasons after the first phase and were not included in the pharmacokinetic analysis. The per-protocol population (11 females, 10 males) had a mean (SD) age of 22 (2) years (range, 19-25 years) and a mean body mass index of 23.6 (3.0) kg/m(2) (range, 19.0-28.5 kg/m(2)). The relative AUC0t and Cmax ratios for the MLR methylphenidate formulation compared with the OROS methylphenidate formulation were 110.88% and 121.84%, respectively. When OROS methylphendate values were dose normalized to 20 mg, the relative AUC0-t and Cmax ratios were 100.72% and 111.82%. The mean Tmax for the 2 formulations was 3.71 (2.03) and 4.96 (2.56) hours. Values were significantly higher with the MLR methylphenidate formulation compared with the OROS methylphenidate formulation for AUC(0-4) (P < 0.001), AUC(0-8) (P < 0.001), AUC(0-12) (P < 0.001), and AUC(4-12) (P = 0.037); the AUC(8-12) was not significantly different between the 2 formulations. Values were significantly higher for the MLR methylphenidate formulation relative to the OROS methylphenidate formulation for C(max0-4) (P < 0.001) and C(max4-12) (P = 0.002). Thirty-seven adverse events occurred in 11 and 10 subjects during receipt of MLR and OROS methylphenidate, respectively. The most commonly reported adverse events in the intent-to-treat population were catheter-site pain, reported by 8 of 24 subjects (33.3%), and headache, reported by 5 of 24 subjects (20.8%). CONCLUSIONS: In these healthy young subjects, MLR methylphenidate was associated with a concentration-time profile that resulted in a higher proportion of the administered methylphenidate dose being delivered in the first 4 hours after dosing compared with OROS methylphenidate while maintaining comparable levels of drug in the latter portion of the dosing interval. This led to maintenance of higher mean levels of methylphenidate throughout the day compared with the closest marketed dose of OROS methylphenidate. The 2 formulations are marketed in dissimilar strengths; however, after correction for administered dose, they yielded similar AUC values.