Single Dose Pharmacokinetics of Kapanol™, a New Oral Sustained-Release Morphine Formulation

Food effects on the pharmacokinetics of morphine sulfate and naltrexone hydrochloride extended release capsules

INTRODUCTION

Morphine sulfate and naltrexone hydrochloride extended release capsules, indicated for chronic moderate-to-severe pain, contain extended-release morphine pellets with a sequestered naltrexone core. If pellets are tampered by crushing, naltrexone is released to reduce morphine-induced effects that appeal to opioid abusers. The primary objective of this study was to assess single-dose relative bioavailability of morphine when morphine sulfate and naltrexone hydrochloride extended release capsules were taken under fed and fasting conditions and when pellets were sprinkled on apple sauce.

METHODS

This was a single-center, randomized, open-label study in 36 healthy adult volunteers. Subjects took a 100-mg morphine sulfate and naltrexone hydrochloride extended release capsule intact with 240 mL water, under fed and fasted conditions, and when the capsule was opened and pellets were sprinkled over apple sauce and consumed without chewing; each treatment was separated by a 14-day washout. Plasma samples were collected just before dosing through 72 hours postdose for pharmacokinetic analyses of morphine, and through 168 hours postdose for naltrexone and its major metabolite 6-β-naltrexol.

RESULTS

Morphine bioavailability was similar for all treatments. There was a lack of sprinkle effect (sprinkle vs. whole, fasted); 90% confidence intervals (CIs) of ratios of log-transformed least squares means for area under the plasma concentration-time curve (AUC) and peak plasma concentration (C(max)) fell within 80%-125% boundaries. For the food effect, 90% CIs were within the boundaries for AUC, but C(max) was reduced and time to C(max) was delayed by 2.5 hours under fed conditions. Naltrexone remained sequestered under all treatment conditions with only trace systemic exposure.

CONCLUSION

Results indicated that morphine sulfate and naltrexone hydrochloride extended release capsules can be administered without regard to meals, and contents can be sprinkled over apple sauce and consumed without chewing by patients with difficulty swallowing.

Morphine sulfate extended-release capsules for the treatment of chronic, moderate-to-severe pain

BACKGROUND

Morphine sulfate extended-release capsules (KADIAN) contain polymer-coated morphine sulfate pellets that are formulated to deliver sustained plasma morphine levels with minimal fluctuation. Morphine sulfate extended-release capsules, the only opioid formulation indicated in the US for both once- and twice-daily (every 12 and every 24 h) dosing, is approved in eight dosage strengths and is effective against pain from diverse sources in a variety of patient types. The formulation of morphine sulfate extended-release capsules allows flexible dosing options: capsules can be taken whole or the contents can be sprinkled on apple sauce or delivered via a gastrostomy tube. Morphine sulfate extended-release capsules have no immediate-release component and no components that would limit high doses.

RESULTS/CONCLUSION

The bioavailability of morphine sulfate extended-release capsules is not compromised when taken with food and dose dumping (immediate elevations in dose) does not occur when morphine sulfate extended-release capsules are taken concomitantly with alcohol. Nearly all patients taking morphine sulfate extended-release capsules for pain relief adhere to the recommended dosing frequency. The flexibility available with morphine sulfate extended-release capsules may offer clinical advantages for pain management.

KADIAN (morphine sulfate extended-release) capsules for treatment of chronic, moderate-to-severe, nonmalignant pain

Chronic pain, one of the most common reasons for which patients seek medical attention, is defined as pain that persists beyond the normal healing time, usually about 3 months. Chronic pain can be malignant or nonmalignant in origin, or can appear in the absence of identifiable pathology. Pharmacological treatment options include non-opioid and opioid analgesics, as well as adjuvant medications. Opioids, the most potent analgesics, are typically reserved for the treatment of chronic, moderate-to-severe pain that has not responded to non-opioid therapy. Morphine remains the gold standard among commonly used opioids. Long-acting opioids are formulated to offer continuous delivery of analgesia around the clock. These agents are formulated to maintain therapeutic blood levels of morphine, with minimal fluctuations. KADIAN Capsules, which contain polymer-coated extended-release morphine sulfate pellets, is one such formulation available for the treatment of moderate-to-severe pain for which an analgesic is indicated for more than a few days. This article reviews KADIAN and identifies unique features from early pharmacokinetic and pharmacodynamic studies, recent data on pharmacokinetic interactions with alcohol and results from recent trials in treating nonmalignant pain.

Randomized trial comparing polymer-coated extended-release morphine sulfate to controlled-release oxycodone HCl in moderate to severe nonmalignant pain

OBJECTIVE

To assess the long-term efficacy, tolerability and safety of polymer-coated extended-release morphine sulfate (P-ERMS) (KADIAN) compared with controlled-release oxycodone HCl (CRO) (OxyContin) in treating chronic, nonmalignant, moderate to severe pain in a community-based outpatient population.

DESIGN

Phase IV, prospective, randomized, open-label.

PARTICIPANTS

Adults (N = 112) with chronic, nonmalignant, moderate to severe pain with visual numeric scale (VNS) scores > or = 4 (0 = no pain; 10 = worst pain).

INTERVENTIONS

Patients were randomized to receive either P-ERMS once-daily (QD) dosing or CRO twice-daily (BID) dosing for a 24-week treatment period. Upward titration of dose and switching P-ERMS to BID or CRO to thrice-daily (TID) dosing was allowed Weeks 2-24.

MAIN OUTCOME MEASURES

Quality of life (Physical [PCS] and Mental [MCS] Component Summary scores of the SF-36v2 Health Survey), pain and sleep scores (0-10), and patient and clinician assessments of current therapy (-4 to +4).

RESULTS

Patients in both treatment groups experienced significant improvements in PCS scores (P-ERMS, +2.6; CRO, +3.1; p < 0.05 vs. baseline); patients taking CRO also demonstrated improvements in MCS scores (+4.7, p < 0.05 vs. baseline). Both groups attained significant reductions from baseline to 24 weeks in pain (P-ERMS, -2.0; CRO, -1.4; p < or = 0.001 vs. baseline); the reduction with P-ERMS was clinically meaningful (as defined by at least a 2-point reduction in VNS score). Patients attained significant improvement in sleep scores (P-ERMS, -2.6; CRO, -1.6; p < 0.001 vs. baseline; p < 0.05, P-ERMS vs. CRO). At Week 24, both groups indicated significantly increased patient (P-ERMS, +2.6; CRO, +1.7; p < 0.001 vs. baseline) and clinician (P-ERMS, +4.0; CRO, +3.1; p < 0.001 vs. baseline) global assessments of therapy. After 24 weeks, all patients on P-ERMS were dosing within the FDA-approved frequencies (65% QD, 35% BID); 56% of patients on CRO dosed BID, but 38% dosed TID and 6% dosed four times daily (QID). Most common adverse events were constipation, nausea, and somnolence, with no significant difference between treatment groups.

CONCLUSIONS

P-ERMS and CRO both relieved chronic nonmalignant pain in this community-based population; however, patients taking P-ERMS dosed in accordance with FDA-approved frequencies (QD/BID); 44% of those taking CRO dosed more frequently (TID/QID).

Treatment of chronic moderate-to-severe non-malignant pain with polymer-coated extended-release morphine sulfate capsules

OBJECTIVE

To demonstrate the efficacy and tolerability of polymer-coated extended-release morphine sulfate (P-ERMS)(KADIAN) for the treatment of chronic, moderate-to-severe, non-malignant pain in a community-based outpatient population not satisfactorily relieved with their current therapies.

DESIGN

Phase IV, prospective, randomized, open-label, blinded endpoint.

PARTICIPANTS

Adults (N = 1428) with chronic, moderate-to-severe, non-malignant pain with visual numeric scale scores >or= 4 (0 = no pain; 10 = worst pain).

INTERVENTIONS

Patients were randomized to P-ERMS once daily in AM or PM for a 4-week treatment period. Dose increases were allowed; however, switching to twice-daily dosing was reserved until week 2.

MAIN OUTCOME MEASURES

Improvement from baseline in pain and sleep scales (0-10) (after weeks 2 and 4), quality of life (physical and mental component summary scores of the SF-36v2 Health Survey) (week 4), and patient (weeks 2 and 4) and clinician (week 4) assessments of current therapy (-4 to +4). Patient satisfaction was assessed again 1 month after the study.

RESULTS

Approximately 70% of patients completed the study, with 2.4% (n = 34) discontinuing due to lack of efficacy, and 9.6% (n = 136) discontinuing due to an adverse event. Improvements were seen in pain and sleep scores, physical and mental component scores of the SF-36v2, and patient and clinician global assessment scores (p < 0.0001, all assessments). Patients attained similar results regardless of AM vs. PM dosing. More than half (55.4%) of patients were maintained on once-daily therapy, with the remainder on a twice-daily regimen, in accordance with the prescribing information. Most adverse events (71.6%) were mild to moderate in severity, the most common being constipation (11.6%) and nausea (9.2%). One-month follow-up indicated continued satisfaction with P-ERMS vs. previous medication (p < 0.0001).

CONCLUSIONS

P-ERMS was efficacious and well tolerated in patients with chronic, moderate-to-severe, non-malignant pain when used once or twice daily.

Comparative pharmacodynamics and pharmacokinetics of methadone and slow-release oral morphine for maintenance treatment of opioid dependence

BACKGROUND

Slow-release oral morphine (SROM) has been proposed as an alternative maintenance pharmacotherapy to methadone for treatment of opioid dependence. However, the pharmacodynamics and pharmacokinetics of SROM have not been previously assessed in a methadone maintenance population.

METHODS

In 14 methadone maintenance patients reporting adequate (holders, n=7) or inadequate (non-holders, n=7) withdrawal suppression between doses, plasma drug concentrations and indices of opioid effect (withdrawal severity, pupil diameter, and respiratory rate) were determined across a 24 h inter-dosing interval on one occasion at steady-state for methadone and SROM (once-daily Kapanol) using an open-label, crossover design.

RESULTS

Opioid effects were of a similar overall magnitude following dosing for each drug and showed an inverse association with plasma drug concentrations, which peaked later for morphine compared to (R)-methadone (6.5 +/- 2.3 h vs. 2.5 +/- 1.4 h, P<0.001). For methadone non-holders, the number of self-reported opioid withdrawal symptoms prior to dosing was less for SROM compared to methadone (3.4 +/- 2.6 vs. 9.0 +/- 3.2, P<0.01); for holders it was approximately equal (4.4 +/- 3.0 vs. 4.0 +/- 3.7, P<0.76). Maintenance doses were more strongly related to plasma drug concentrations for SROM compared to methadone and may thus be more predictive of therapeutic response for the former medication. Twelve of the 14 subjects preferred SROM to methadone (P=0.01).

CONCLUSIONS

The pharmacodynamics and pharmacokinetics of SROM support its use as an alternative once-daily agonist option in the treatment of opioid dependence, particularly for patients responding poorly to methadone maintenance treatment.

Drug delivery research in Australasia: creating opportunities through collaboration

This paper gives a brief overview of drug delivery research in Australia and New Zealand, known collectively as Australasia, in order to indicate future directions in this area of pharmaceutical research. It describes some of the relevant statistics of the two countries and briefly indicates some of the government incentives to foster the pharmaceutical industries. Examples of Australian drug delivery research such as a controlled release pelleted system for delivery of morphine are presented. The examples for New Zealand relate to veterinary systems such as an intraruminal device for zinc. The paper alludes to the need for collaboration among the various institutions in order to achieve successful outcomes.

Controlled-release morphine tablets in patients with chronic cancer pain: a narrative review of controlled clinical trials

BACKGROUND

Controlled-release (CR) morphine tablets have become routine therapy in the management of cancer pain. Compared with immediate-release (IR) morphine, this formulation provides the benefit of dosing every 12 hours.

METHODS

This study reviewed the 10 published, well controlled, repeated-dose, comparative studies with CR morphine tablets administered every 12 hours to patients with cancer pain.

RESULTS

CR morphine tablets were uniformly effective; 98% of patients completed a treatment course of every-12-hours therapy. Although the effective analgesic dose varied considerably from study to study (range, 90-330 mg per day), pain was well controlled with CR morphine tablets as the primary analgesic. Mean pain scores, converted to a common 10-point scale, ranged from 1.1-2.9 across all studies. There was only occasional need for IR morphine rescue medication (range, 2-39 mg per day). The mean discontinuation rate because of side effects or lack of every-12-hours efficacy was 2%. In seven studies that used IR morphine as the comparative agent, CR morphine tablets were found to be equally effective as IR morphine.

CONCLUSIONS

Twice-daily dosing of CR morphine provides convenient, safe, and effective relief of cancer pain.

Comparison of a once-a-day sustained-release morphine formulation with standard oral morphine treatment for cancer pain

Kadian/Kapanol (K) is a capsule formulation of morphine designed for 12- or 24-hourly dosing. This double-blind study compared the efficacy and safety of K every 24 hr to K every 12 hr and MS Contin tablets (MSC) every 12 hr. One hundred fifty-two patients with cancer pain were titrated to adequate analgesia with immediate-release morphine (IRM) solution. Stabilized patients were randonized to one of the three treatments for 7 +/- 1 days. Rescue medication was IRM tablets. Efficacy and safety were assessed by time to first remedication and total dose of rescue medication, pain scores, global assessments, and incidence of morphine-related side effects. Fifty-four patients were treated with K every 24 hr. 45 with K every 12 hr. and 53 with MSC every 12 hr. Mean age was 61 years and mean total daily dose of morphine was 138 mg. Forty-six percent of the K every 24 hr patients, 51% of the K every 12 hr patients, and 55% of the MSC every 12 hr patients required rescue medication on the final day. Time to remedication was 16.0 hr for K every 24 hr, 9.1 hr for K every 12 hr and 8.7 hr for MSC every 12 hr (P = 0.0010). Patient global assessment significantly favored K every 24 hr over MSC every 12 hr (P = 0.018). There were no statistically significant differences among the treatments for any morphine-related side effects when adjusted for baseline. K had efficacy and safety profiles similar to MSC every 12 hr but had the advantage of 12- or 24-hourly administration.

The effect of food intake on the pharmacokinetics of sustained-release morphine sulfate capsules

The effect of food intake on the pharmacokinetics of sustained-release (SR) morphine sulfate capsules was assessed in 24 healthy male volunteers. Subjects were randomized to receive a single, 20-mg SR morphine sulfate capsule while fasting and immediately after consumption of a standard high-fat meal. Plasma samples were masked for pharmacokinetic analysis. Although the extent of absorption of the SR preparation was comparable in subjects in the fed and fasted states, plasma morphine concentrations were significantly lower at most sampling times up to 10 hours when the drug was administered after a high-fat meal. The rate of absorption of morphine from the SR capsule was slower with food intake as evidenced by a 13% decrease in the maximum concentration (Cmax), a 28% increase in the half-life of absorption, and a 19% increase in the time to Cmax. Results of this study indicate that food intake had an effect on the overall plasma-concentration-versus-time profile of the SR morphine sulfate oral preparation, the extent of which was not revealed by a comparison of Cmax and area under the plasma concentration-time curve values alone.