Rofecoxib in patients with mild cognitive impairment: further analyses of data from a randomized, double-blind, trial.

A recent clinical trial in patients with Mild Cognitive Impairment (MCI) found an increased rate of possible or probable Alzheimer's disease (AD) diagnoses in patients assigned to rofecoxib compared to placebo. This unexpected finding was difficult to interpret due to methodological issues and a lack of confirmation on secondary endpoints, as well as a lack of confirmation in trials in related populations. We performed additional post hoc analyses to explore explanations for the finding based on possible neuropathological, cardiovascular/cerebrovascular, or cognitive effects of rofecoxib. 1) Neuropathological hypothesis: Of the 189 incident cases of possible or probable AD, 154 were probable AD. In probable AD patients, the treatment hazard ratio was reduced compared to the primary analysis -- a concordant finding would have strengthened a conclusion that rofecoxib accelerated the underlying neuropathology of AD. The treatment hazard ratio was increased in the remaining 35 patients with less certain diagnoses, but there was no single predominant reason for the reduced certainty of diagnosis. 2) Cardiovascular hypothesis: Neither cardiovascular risk status nor mean arterial blood pressure had an overall effect on AD diagnosis or modified the treatment difference. 3) Cognitive side-effects hypothesis: The percentages of patients with non-specific NSAID-type central nervous system adverse events were similar between the treatment groups. In summary, the present analyses are limited by their post hoc nature but provided little support for any of the possible explanations explored. The significance of the observation that rofecoxib increased the rate of conversion from MCI to AD remains uncertain.

Single- and multiple-dose pharmacokinetics of biphasic immediate-release/extended-release hydrocodone bitartrate/acetaminophen (MNK-155) compared with immediate-release hydrocodone bitartrate/ibuprofen and immediate-release tramadol HCl/acetaminophen.

OBJECTIVE: To characterize the single-dose and steady-state pharmacokinetics (PK) of biphasic immediate-release/extended-release hydrocodone bitartrate/acetaminophen (IR/ER HB/APAP), IR HB/ibuprofen, and IR tramadol HCl/APAP. METHODS: In this single-center, open-label, randomized, four-period crossover study, healthy participants received four treatments under fasted conditions: 1) a single dose of two IR/ER HB/APAP 7.5/325 mg tablets (15/650 mg total dose) on day 1, followed by two tablets every 12 hours (q12h) beginning on day 3; 2) a single dose of IR HB/ibuprofen 15/400 mg (divided as one 7.5/200 mg tablet at hour 0 and 6), followed by one tablet every 6 hours (q6h) beginning on day 3; 3) a single dose of IR tramadol HCl/APAP 75/650 mg (divided as one 37.5/325 mg tablet at hour 0 and 6), followed by one tablet q6h beginning on day 3; and 4) a single dose of three IR/ER HB/APAP 7.5/325 mg tablets (22.5/975 mg total dose) on day 1, a three-tablet initial dose at 48 hours followed by two-tablet doses q12h beginning on day 3. Hydrocodone and APAP single-dose and steady-state PK were assessed. Adverse events were monitored. RESULTS: The PK analysis was carried out on 29 of 48 enrolled participants who completed all treatment periods. Single-dose hydrocodone exposure was similar for IR/ER HB/APAP 22.5/975 mg and IR HB/ibuprofen 15/400 mg; time to maximum observed plasma concentration was shorter and half-life was longer for IR/ER HB/APAP (22.5/975 mg and 15/650 mg) vs IR HB/ibuprofen. Single-dose APAP exposure was similar for IR/ER HB/APAP 15/650 mg and IR tramadol HCl/APAP 75/650 mg. Steady-state hydrocodone and APAP exposures were similar between treatments. Adverse events were similar for each treatment and typical of low-dose combination opioid analgesics. With dosing q12h, IR/ER HB/APAP had half as many concentration peaks and troughs as the comparators treated q6h. CONCLUSION: With dosing q12h, IR/ER HB/APAP provided similar peak and total steady-state hydrocodone and APAP exposure vs IR comparators.

Single-dose pharmacokinetics of 2 or 3 tablets of biphasic immediate-release/extended-release hydrocodone bitartrate/acetaminophen (MNK-155) under fed and fasted conditions: two randomized open-label trials.

BACKGROUND: Biphasic immediate-release (IR)/extended-release (ER) hydrocodone bitartrate (HB)/acetaminophen (APAP) 7.5/325-mg tablets are formulated with gastroretentive ER drug delivery technology that has been associated with clinically meaningful food effects in other approved products. Two phase 1 studies evaluated potential effects of food on single-dose pharmacokinetics of IR/ER HB/APAP tablets. METHODS: These were single-center, open-label, randomized, single-dose, 3-period crossover studies in healthy volunteers (aged 18-55 years). IR/ER HB/APAP was administered as a single 2-tablet dose (study 1) or 3-tablet dose (study 2) under fed (high- and low-fat) and fasted conditions. Area under the plasma concentration-time curve from 0 h to time t (AUC0-t) and from time 0 extrapolated to infinity (AUC0-inf) and maximum observed plasma concentration (Cmax) of hydrocodone and APAP under fed versus fasted conditions were compared using analysis of variance. A 90% confidence interval of the geometric least squares mean ratio fully contained within 80 to 125 % indicated no treatment difference. Safety and tolerability were assessed. RESULTS: Forty of 48 participants in study 1 and 21 of 30 in study 2 completed all treatments. In both studies, under fed (high- or low-fat meal) versus fasted conditions, 90% CIs for AUC0-t and AUC0-inf for both hydrocodone and APAP were entirely contained within the bioequivalent range (80-125%), indicating that high- and low-fat meals did not affect the extent of exposure. In both studies, a high-fat meal did not affect the Cmax for hydrocodone. Hydrocodone Cmax was not affected by a low-fat meal in study 1 but increased by approximately 19% in study 2. A high-fat meal decreased APAP Cmax by approximately 20 % (study 1) and 13 % (study 2); a low-fat meal decreased APAP Cmax by 22% (study 1) and 21% (study 2). Approximately 50% of participants in both studies reported ≥1 treatment-emergent adverse event (TEAE), with no notable difference based on food intake. There were no serious or severe AEs. The most common TEAEs were nausea, vomiting, and dizziness. CONCLUSIONS: Pharmacokinetic and safety findings were similar regardless of food intake. TEAEs were consistent with those reported with low-dose combination opioids. IR/ER HB/APAP can be administered without regard to food. TRIAL REGISTRATION: ClinicalTrials.gov NCT02561650 and NCT02561741 .

Comparison of single-dose and multiple-dose pharmacokinetics between two formulations of hydrocodone bitartrate/acetaminophen: immediate-release versus biphasic immediate-release/extended release.

OBJECTIVE: This study aimed to compare the single-dose and steady-state pharmacokinetics (PK) of biphasic immediate-release (IR)/extended-release (ER) hydrocodone bitartrate (HB)/acetaminophen (APAP) and IR HB/APAP. SETTING: The study was conducted in a contract research center. PARTICIPANTS: The study included healthy adults. INTERVENTIONS: In a three-way crossover study, Study 1, participants received the following treatments: (A1) a single dose of IR/ER HB/APAP 7.5/325 mg one tablet, followed by one tablet every 12 hours (q12h); (B1) a single dose of IR/ER HB/APAP 7.5/325 mg two tablets, followed by two tablets q12h; (C1) a single dose of IR HB/APAP 7.5/325 mg two tablets (one tablet at hours 0 and 6), followed by one tablet q6h. In a two-way crossover study, Study 2, participants received the following treatments: (A2) an initial dose of IR/ER HB/APAP 7.5/325 mg three tablets, followed by two tablets q12h; (B2) three doses of IR HB/APAP 7.5/325 mg one tablet q4h, followed by one tablet q6h. MAIN OUTCOME MEASURES: PK values were compared, and adverse events were assessed. RESULTS: Single-dose and steady-state area under the concentration-time curves for hydrocodone and APAP were similar for IR/ER and IR HB/APAP; the steady-state peak plasma concentrations (C max) at steady state were also similar, but single-dose C max for hydrocodone was lower for IR/ER HB/APAP. For most PK parameters, 90% confidence intervals for geometric least squares mean ratios were not meaningfully different (80%-125%). Steady state was achieved in 2-3 days for IR/ER HB/APAP and in 2 days for IR HB/APAP. Median time to C max was longer for IR/ER HB/APAP versus IR HB/APAP (P,0.05). Adverse events were similar across treatments. CONCLUSION: PK outcomes and tolerability were similar for IR/ER HB/APAP and IR HB/APAP.

Tolerability of Biphasic-Release Hydrocodone Bitartrate/Acetaminophen Tablets (MNK-155): A Phase III, Multicenter, Open-Label Study in Patients With Osteoarthritis or Chronic Low Back Pain.

PURPOSE: This study aimed to assess the tolerability of the extended use (≤35 days) of MNK-155, a biphasic (immediate-release/extended-release) hydrocodone bitartrate/N-acetyl-p-aminophenol (acetaminophen) (IR/ER HB/APAP) 7.5/325-mg fixed-dose combination analgesic agent, in patients with chronic noncancer pain (CNCP) caused by osteoarthritis or chronic low back pain. IR/ER HB/APAP tablets deliver 25% of the HB dose and 50% of the APAP dose by IR and the remainder by ER over a 12-hour dosing interval. Although IR/ER HB/APAP is being developed for the management of moderate to severe acute pain, this model of CNCP was used for assessing tolerability over a term longer than would be possible in a model of acute pain. METHODS: This Phase III, multicenter, open-label study enrolled patients with moderate to severe OA (knee or hip) pain despite the use of nonopioid or opioid analgesic agents, or with moderate to severe CLBP present for several hours per day for ≥3 months. Patients received a 3-tablet initial dose of IR/ER HB/APAP (total dose, 22.5/975 mg) on day 1, followed by 2 tablets of IR/ER HB/APAP (total dose, 15/650 mg) q12h for up to 35 days. Tolerability, the primary end point, was assessed using time to treatment discontinuation, the prevalence of treatment-emergent adverse events (TEAEs), vital sign measurements, pulse oximetry, clinical laboratory tests, and compliance. Secondary outcomes included the modified Brief Pain Inventory-Short Form, the Western Ontario and McMaster Universities Arthritis Index, and The Roland-Morris Low Back Pain and Disability Questionnaire. FINDINGS: Of the 153 patients enrolled (95 women [62.1%]; mean age, 53.9 [14.5] years; OA, n = 73; CLBP, n = 80), 37 (24.2%) discontinued the study early (mean time to discontinuation, 21.3 days). Thirteen patients (8.5%) discontinued because of TEAEs. A total of 88 patients (57.5%) reported ≥1 TEAE, 65 (42.5%) of whom experienced AEs considered by the investigator as treatment related. The most frequent TEAEs were nausea (16.3%), somnolence (14.4%), and constipation (11.1%). Eight severe TEAEs were experienced by 6 (3.9%) patients and included single occurrences of nausea, fatigue, nasopharyngitis, elevated liver enzymes, headache, nightmare, and ejaculation delay. No serious treatment-related AEs were reported. Clinically significant changes in laboratory values were reported in 13 patients, 6 of whom had abnormal liver function test results that did not meet Hy's law criteria for acute liver failure. Most laboratory abnormalities were mild and transient. Measures of pain intensity, function, and quality of life improved from baseline but in an open-label study these changes cannot be attributed to treatment. IMPLICATIONS: The safety profile of IR/ER HB/APAP during extended use was consistent with those of other low-dose opioid/APAP combination products. IR/ER HB/APAP is intended for acute pain; its efficacy for relief of CNCP would require further evaluation in an active- or placebo-controlled study. ClinicalTrials.gov Identifier: NCT01722864.

Randomized, double-blind, placebo-controlled study of the efficacy and safety of biphasic immediate-release/extended-release hydrocodone bitartrate/acetaminophen tablets for acute postoperative pain.

BACKGROUND: A fixed-dose combination biphasic immediate-release (IR)/extended-release (ER) hydrocodone bitartrate (HB)/acetaminophen (APAP) tablet is being developed for the management of acute pain severe enough to require opioid treatment and for which alternative treatment options are inadequate. METHODS: This Phase III, randomized, double-blind, placebo-controlled, parallel-group study evaluated the analgesic efficacy and safety of IR/ER HB/APAP (n = 201) versus placebo (n = 202) over a period of 48 hours in patients with acute moderate to severe pain following unilateral bunionectomy. Patients received three tablets of placebo or IR/ER HB/APAP as an initial dose (hour 0) followed by two tablets every 12 hours for a total daily dose of 37.5/1625 mg HB/APAP on day 1 and 30/1300 mg HB/APAP thereafter. The primary efficacy outcome was the summed pain intensity difference (SPID) over the first 48 hours (SPID48) after the first dose. RESULTS: SPID48 was significantly greater with IR/ER HB/APAP versus placebo (p < 0.001). SPID dosing interval analyses demonstrated consistent, superior pain relief with IR/ER HB/APAP for each dosing interval (all p < 0.001). Mean PID was greater with IR/ER HB/APAP versus placebo beginning 30 minutes after the first dose (p < 0.05), and IR/ER HB/APAP demonstrated faster median time to the onset of perceptible, meaningful, and confirmed pain relief (all p < 0.001). Mean total pain relief scores also indicated greater pain relief with IR/ER HB/APAP versus placebo throughout the 48-hour period (p = 0.012) for all comparisons. A greater proportion of IR/ER HB/APAP versus placebo patients was either "very satisfied" or "satisfied" with their pain relief (69.3% vs 49.4%; p < 0.001). Nausea was the most common treatment-emergent adverse event (TEAE; IR/ER HB/APAP, 25%; placebo, 7.9%). All TEAEs in IR/ER HB/APAP-treated patients were mild or moderate in severity. CONCLUSION: IR/ER HB/APAP provided rapid, significant, and consistent analgesic efficacy over a period of 48 hours in an established model of acute pain and was tolerated with a safety profile similar to other low-dose opioids.

Novel CLCN1 mutations with unique clinical and electrophysiological consequences.

Myotonia is a condition characterized by impaired relaxation of muscle following sudden forceful contraction. We systematically screened all 23 exons of the CLCN1 gene in 88 unrelated patients with myotonia and identified mutations in 14 patients. Six novel mutations were discovered: five were missense (S132C, L283F, T310M, F428S and T550M) found in heterozygous patients, and one was a nonsense mutation (E193X) in a homozygous patient. While five patients had a clinical diagnosis of myotonia congenita, the patient with the F428S mutation exhibited symptoms characteristic of paramyotonia congenita--a condition usually thought to be caused by mutations in the sodium channel gene SCN4A. Nevertheless, no mutations in SCN4A were identified in this patient. The functional consequences of the novel CLCN1 sequence variants were explored by recording chloride currents from human embryonic kidney cells transiently expressing homo- or heterodimeric mutant channels. The five tested mutations caused distinct functional alterations of the homodimeric human muscle chloride ion channel hClC-1. S132C and T550M conferred novel hyperpolarization-induced gating steps, L283F and T310M caused a shift of the activation curve to more positive potentials and F428S reduced the expression level of hClC-1 channels. All showed a dominant-negative effect. For S132C, L283F, T310M and T550M, heterodimeric channels consisting of one wild-type (WT) and one mutant subunit exhibited a shifted activation curve at low intracellular [Cl(-)]. WT-F428S channels displayed properties similar to WT hClC-1, but expressed at significantly lower levels. The novel mutations exhibit a broad variety of functional defects that, by distinct mechanisms, cause a significant reduction of the resting chloride conductance in muscle of heterozygous patients. Our results provide novel insights into functional alterations and clinical symptoms caused by mutations in CLCN1.