A pharmacokinetic evaluation of single and multiple doses of extended-release hydrocodone bitartrate in subjects experiencing surgical or osteoarthritic pain.

OBJECTIVES: To assess the single-dose and steady-state pharmacokinetics of a single-entity hydrocodone extended-release (ER) formulation in patients enrolled in two separate phase 2 clinical studies. SETTING: Both studies were multicenter clinical studies. SUBJECTS AND INTERVENTIONS: In study 1, 115 subjects with postsurgical pain (bunionectomy) received single doses of 10, 20, 30, or 40 mg hydrocodone-ER, 10 mg hydrocodone/325 mg acetaminophen immediate-release (IR), or placebo. In study 2, 37 subjects with osteoarthritic pain received doses of 10, 20, 30, or 40 mg of hydrocodone- ER twice-daily for 7 days. Venous blood samples were taken periodically up to 24 hours postdosing after the single dose (study 1) or after 7 days of dosing (study 2) and were assayed for concentrations of hydrocodone and its major metabolites. MAIN OUTCOME MEASURES: Standard pharmacokinetic parameters were estimated by noncompartmental analysis methods. RESULTS: Following a single dose of hydrocodone-ER, Tmax was prolonged to approximately 6 hours at all dose levels of hydrocodone-ER compared with 2.9 hours for the IR formulation. All doses of hydrocodone-ER formulations provided prolonged and sustained release of hydrocodone throughout the 12-hour dosing interval with reduced peak-to-trough fluctuation at steady state compared with hydrocodone/acetaminophen-IR comparator. Both single-dose and steadystate mean Cmax and AUClast values showed reasonable dose-proportionality. Norhydrocodone and hydromorphone plasma concentrations were 32-38 percent and <2.1 percent, respectively, of hydrocodone concentrations in both studies. CONCLUSIONS: The sustained plasma concentrations of hydrocodone support twice-daily dosing with a 12-hour dosing interval.

Relationship between change in pain intensity and functional outcomes in patients with chronic pain receiving twice daily extended-release hydrocodone bitartrate.

OBJECTIVE: Evaluate levels of pain relief achieved in patients with chronic pain treated with hydrocodone-extended release (HC-ER) up to 48 weeks and show that these levels were associated with secondary functional and global outcomes. DESIGN: Post hoc analyses were based on a previously reported study that started with an open-label conversion/titration phase for ≤ 6 weeks followed by an openlabel 48-week treatment phase. SETTING: Private practice and institutional pain centers. PARTICIPANTS: Three hundred ninety-one opioid-experienced subjects with moderate to severe pain for ≥ 3 months. INTERVENTIONS: Individualized doses (20-300 mg) of extended-release hydrocodone every 12 hours. MAIN OUTCOME: Almost 60 percent (232/391) of subjects achieved moderate or substantial levels of pain relief (≥ 30 percent reduction in pain score) during the study. RESULTS: Subjects who achieved moderate or substantial pain relief demonstrated significant (p <0.001) improvements in Oswestry Disability Inventory (ODI), all pain interference outcomes, and Subject Global Assessment of Medication. Subjects with substantial pain relief had decreases in ODI, Hospital Anxiety and Depression Scale (HADS) anxiety, and HADS depression scores of -13.4 ± 14.92, -1.9 ± 3.37, and -1.7 ± 3.26, respectively. The five most commonly reported treatment-emergent adverse events were constipation (12.5 percent), back pain (11.1 percent), nausea (9.9 percent), vomiting (9.7 percent), and arthralgia (7.8 percent) and are consistent with opioid therapy. CONCLUSIONS: Moderate or substantial levels of pain relief were associated with the greatest functional improvements in patients treated with HC-ER. These results may help define success of opioid therapy and determine if it should be continued or an alternative treatment should be tried.

An Analysis of Rescue Medication Utilization from a 3-Month, Randomized, Double-Blind, Placebo-Controlled Study in Patients with Chronic Low Back Pain Treated with Single-Entity, Twice-Daily, Extended-Release Hydrocodone.

OBJECTIVE: To evaluate the durability of pain relief provided by a new formulation of single-entity, hydrocodone extended-release (ER) (Zohydro(®) ER) throughout the 12-hour dosing interval by examining patterns of rescue medication use. DESIGN: Phase 3, enriched enrollment, randomized withdrawal study with an open-label, conversion/titration phase (≤6 weeks) followed by a placebo-controlled, double-blind treatment phase (12 weeks). SETTING: Fifty-seven study sites in the United States enrolled patients. SUBJECTS: One hundred and fifty-one opioid-experienced subjects with moderate to severe chronic low back pain who were treated with hydrocodone ER once every 12 hours. METHODS: Post hoc analysis of rescue medication use by frequency and distribution of use following the morning and evening dose of hydrocodone ER. RESULTS: No rescue medication was used following the morning or evening dose of hydrocodone ER during 36.0% and 76.7% of the dosing days, respectively. Time distribution of rescue medication use showed that 79.3% of all rescue medication doses were administered following the morning dose, with the highest rate of usage (46.2%) occurring 4-8 hours postdose, followed by 18.7% and 14.4% usage 0-4 and 8-12 hours postdose, respectively. Examination of the three 4-hour intervals following the evening dose of hydrocodone ER revealed similar minimal rescue medication use (5.6-8.2%). CONCLUSIONS: End-of-dose failure was not observed based on the use of rescue medication after administration of single-entity, twice daily, hydrocodone ER capsules (Zohydro ER).

Effects of food and alcohol on the pharmacokinetics of an oral, extended-release formulation of hydrocodone in healthy volunteers.

BACKGROUND: The purpose of this study was to evaluate the pharmacokinetics, bioavailability, and safety of oral extended-release hydrocodone (HC-ER) when administered with food or alcohol. METHODS: Two single-center, open-label, randomized, crossover studies were conducted in healthy volunteers. In a two-period food-interaction study, 12 subjects received HC-ER 20 mg after an overnight fast and a high-fat meal. In a three-period alcohol-interaction study, 30 naltrexone-blocked subjects received HC-ER 50 mg with a 0%, 20%, or 40% alcohol/orange juice solution after an overnight fast. Pharmacokinetic parameters were derived from plasma concentrations of hydrocodone and its metabolites. RESULTS: Exposure to hydrocodone after HC-ER 20 mg was similar in the fed and fasted states, as assessed by area under the plasma concentration versus time curve from time of dosing to time of last detectable concentration (AUC0-t; 316.14 versus 311.94 ng · h/mL); relative bioavailability (Frel) was 101.74%. Differences (fed versus fasted) in hydrocodone mean maximum plasma concentration (Cmax; 28.86 versus 22.74 ng/mL) and median time to Cmax (tmax; 6 versus 8 hours) were not clinically significant. Administration of 20% alcohol with HC-ER 50 mg did not increase systemic exposure relative to 0% alcohol (AUC0-t 878 versus 832 ng · h/mL; Frel 105%) or result in clinically meaningful changes in Cmax (51.8 versus 46.3 ng/mL) or tmax (5.44 versus 6.16 hours). Administration with 40% alcohol increased AUC0-t (1,008 ng · h/mL versus 832 ng · h/mL; Frel 120%) and Cmax (109 versus 46.3 ng/mL), and shortened tmax (2.43 versus 6.16 hours). Adverse events occurred in 10.0%, 24.1%, and 66.7% of subjects after 0%, 20%, and 40% alcohol, respectively. CONCLUSION: HC-ER can be administered without regard to meals. While there was no evidence of "dose-dumping" (an unintended, rapid release in a short time period of all or most of the hydrocodone from HC-ER), even with 40% alcohol, as with all opioids, alcohol should not be ingested while using HC-ER.

A long-term, open-label safety study of single-entity hydrocodone bitartrate extended release for the treatment of moderate to severe chronic pain.

OBJECTIVE: To evaluate the long-term safety, tolerability, and effectiveness of single-entity extended-release hydrocodone in opioid-experienced subjects with moderate to severe chronic pain not receiving adequate pain relief or experiencing intolerable side effects from their current opioid. METHODS: This multicenter, open-label study started with a conversion/titration phase (≤6 weeks) where subjects (n=638) were converted to individualized doses (range 20-300 mg) of extended-release hydrocodone dosed every 12 hours, followed by a 48-week maintenance phase (n=424). The primary objective (safety and tolerability) and the secondary objective (long-term efficacy as measured by change in average pain score; 0= no pain, 10= worst imaginable pain) were monitored throughout the study. RESULTS: Subjects were treated for a range of chronic pain etiologies, including osteoarthritis, low back pain, and neuropathic and musculoskeletal conditions. The mean hydrocodone equivalent dose at screening was 68.9±62.2 mg/day and increased to 139.5±81.7 mg/day at the start of the maintenance phase. Unlimited dose adjustments were permitted at the investigator's discretion during the maintenance phase, reflecting typical clinical practice. No unexpected safety issues were reported. Common adverse events during the conversion/titration and maintenance phases, respectively, were constipation (11.3% and 12.5%), nausea (10.7% and 9.9%), vomiting (4.1% and 9.7%), and somnolence (7.7% and 4.2%). Four deaths occurred during the study; all were considered unrelated to treatment. One subject died 13 months after the study ended. From the start to end of the conversion/titration phase, 84% of subjects had a clinically meaningful improvement in average pain score (≥30% improvement), and the mean average pain scores remained stable through the maintenance phase. CONCLUSION: This single-entity, extended-release formulation of hydrocodone was generally safe, well tolerated, and effective in reducing chronic pain for 48 weeks. This formulation provides a new option for patients experiencing chronic pain, especially those who are taking immediate-release hydrocodone and have concerns about liver toxicity due to acetaminophen.

Single-entity hydrocodone extended-release capsules in opioid-tolerant subjects with moderate-to-severe chronic low back pain: a randomized double-blind, placebo-controlled study.

OBJECTIVE: A single-agent, extended-release formulation of hydrocodone (HC) has been developed for treatment of chronic moderate-to-severe pain. This study was designed to examine the safety and efficacy of HC extended release in opioid-experienced adults with moderate-to-severe chronic low back pain (CLBP). METHODS: This multicenter, enriched enrollment, randomized withdrawal study comprised an open-label conversion/titration phase (≤6 weeks) followed by placebo-controlled, double-blind treatment (12 weeks). During the conversion/titration phase, subjects (N = 510) converted from their current opioid and were titrated to a stabilized dose of HC extended release (20-100 mg every 12 hours). During treatment, subjects (N = 151 per group) received HC extended release or placebo; rescue medication was permitted. The primary efficacy end point was mean change in average pain intensity from baseline to day 85. Response rates (30% pain improvement) and satisfaction (Subject Global Assessment of Medication) were assessed. RESULTS: Demographic and baseline characteristics were similar between groups. Mean ± SD change in average pain intensity score from baseline to day 85 was significantly lower in the HC extended-release treatment group vs placebo (0.48 ± 1.56 vs 0.96 ± 1.55; P = 0.008). Significantly more responders were in the treatment group (68% vs 31%; P < 0.001). Mean Subject Global Assessment of Medication scores increased significantly (0.8 ± 1.3 vs 0.0 ± 1.4; P < 0.0001), indicating greater satisfaction with HC extended release. The adverse event profile was consistent with other opioids. CONCLUSIONS: Extended-release HC is well tolerated and effective, without acetaminophen-associated risks of liver toxicity, for treatment of CLBP.

Population pharmacokinetic analysis for hydrocodone following the administration of hydrocodone bitartrate extended-release capsules.

BACKGROUND AND OBJECTIVE: Hydrocodone is a semi-synthetic narcotic analgesic and antitussive. Although hydrocodone products have been on the market for over 50 years, relatively little is known about its pharmacokinetics. Additionally, there are no published reports of population pharmacokinetic analyses for hydrocodone. Furthermore, current labeling of hydrocodone-containing products provides little guidance in terms of the impact of patient descriptors on the pharmacokinetics of hydrocodone. The objectives of this analysis were to develop a population pharmacokinetic model that characterizes the pharmacokinetics of hydrocodone following single and multiple oral doses of hydrocodone extended-release capsules (hydrocodone bitartrate ER capsules) in healthy subjects and patients, to examine the impact of patient descriptors on pharmacokinetic parameters and to assess the dose-proportionality of hydrocodone pharmacokinetic. METHODS: A total of 4,714 plasma hydrocodone concentrations from 220 subjects were available for this analysis. The data were extracted from seven studies (five phase 1 and two phase 2 studies). A two-compartment open mamillary model with linear elimination and a complex absorption model was used to fit the data, using NONMEM(®) version 7.1.2 software. The absorption model involved two sequential first-order absorption processes with the delay in the first process accomplished by means of multiple transit compartments. Covariate analysis was performed using standard forward selection followed by backward elimination processes. Model evaluation was performed using a prediction-corrected visual predictive check (pcVPC). RESULTS: The population estimates of apparent oral central volume of distribution and apparent oral linear clearance were 714 L and 64.4 L/h, respectively. The first absorption process was rapid. Creatinine clearance and body surface area (BSA) were statistically significant predictors of the apparent oral clearance and apparent oral volume of distribution. The pcVPC indicated that the model provided a robust and unbiased fit to the data. CONCLUSIONS: A linear model for hydrocodone elimination provided an adequate fit to the observed data over the entire dose range, which supports that hydrocodone bitartrate ER capsules exhibit dose-proportional pharmacokinetics. The formulation of hydrocodone bitartrate ER capsules results in absorption profiles that are variable across and within subjects. Despite the variability in absorption profiles, a relatively simple model provided an adequate fit to the data. Creatinine clearance and BSA were statistically significant predictors of the apparent oral clearance and apparent oral volume of distribution. Absorption characteristics of hydrocodone bitartrate ER capsules should still allow effective plasma concentrations of hydrocodone to be reached quickly and for effective concentrations to be maintained for a long period.