Morphine is the archetypal opioid analgesic. Because it is a short-acting opioid, its use has been limited to the management of acute pain. The development of extended-release formulations have resulted in the increased utilization of morphine in chronic pain conditions. This review documents the history of morphine use in pain treatment, and describes the metabolism, pharmacodynamics, formulations, and efficacy of the currently available extended-release morphine medications.

Urine drug monitoring is used by physicians treating chronic pain patients with opioid therapy. Patients are tested in part to insure that they are not taking other drugs. Therefore, the finding of codeine in a patient who is only prescribed morphine has clinical implications. Morphine preparations are known to have small amounts of codeine as an impurity estimated to be about 0.04%. In a population of 535 pain patients prescribed morphine, Kadian, MS Contin, and/or Avinza, the investigators observed 24 samples that contained codeine >20 ng/mL. Fifteen of the 24 contained codeine >20 and <50 ng/mL. Of the 9 samples that were >50 ng/mL, 7 had high levels of codeine (indicating codeine use), 1 was from a patient who had a prescription for codeine, and 1 was also positive for 6-acetylmorphine, indicating heroin use. A control group of 680 patients taking oxycodone was negative for codeine. The finding of codeine was ascribed to the manufacturing process of the morphine medications. Clinicians and laboratories testing urine for drugs should be aware of this possibility.

To evaluate the impact of an extended-release, once-daily morphine sulfate formulation on depressive symptoms and neurocognition in patients with chronic nonmalignant pain.Prospective, open-label, one-group trial with a pretest-posttest design.Outpatient pain management clinic.Chronic nonmalignant pain patients inadequately controlled with short-acting opioid analgesics and eligible for treatment with once-daily morphine sulfate were initiated on a dose at or near the morphine-equivalent dose of the short-acting regimen.The following assessments were made at baseline and 4 weeks after initiating intervention: pain intensity, pain unpleasantness, pain suffering, pain behaviors, Beck Depression Inventory, and cognitive function.Eighty-four patients provided usable data. Pain intensity, unpleasantness, and suffering scores were significantly reduced at follow-up (P = 0.001). The mean Beck Depression Inventory scores were significantly lower at follow-up (P = 0.001). Significant improvements were seen in scores at follow-up on the three validated neurocognitive tests: the digit span test, the digit symbol substitution test, and the paced auditory serial addition test (P = 0.001).Achieving adequate pain control with once-daily morphine was associated with a reduction in pain and improvements in depressive symptoms and cognitive functioning in the short term.

To investigate the effect of once-a-day extended release of morphine sulfate AVINZA (A-MQD) on polysomnographic measures of sleep in a population of chronic osteoarthritic pain patients with sleep difficulties.Single-center, single-blind, placebo-lead-in, 30 mg or 60 mg. Patients' sleep and neurocognition were objectively measured at a sleep laboratory, and patients self-rated their pain, sleep, and other functions.Thirty-four participants (26 to 75 years old) complaining of sleep difficulties and chronic, stable pain secondary to hip or knee osteoarthritis.Participants had a screening visit on current pain medication and then, following a single-blind placebo run-in period, received 30 mg/d of A-MQD for six days. At day 6, doses for participants with incomplete pain relief on the Brief-Pain-Inventory (BPI) pain scale were increased to 60 mg/d. Treatment continued for another eight days at the new dose level (14 days for a subgroup at 60 mg/d). Sleep was objectively measured by all-night polysomnography (PSG) at screening while on the participants' current pain therapy, at baseline following a placebo run-in and at the end of treatment while on A-MQD.PSG parameters evaluated included Total-Sleep-Time (TST), Wake-timeafter-Sleep-Onset (WASO), Sleep-Efficiency (SE), Latency-to-Persistent Sleep (LPS), Latency-to-REM-sleep, the Number-of-Awakenings (NAW), the time spent in each stage of sleep, and REM-sleep-latency. Subjective evaluations included participants' estimations of sleep time and sleep quality, the Epworth-Sleepiness-Scale (ESS), the BPI, and participant acceptance of and relief due to current therapy. Assessments of neurocognitive function were also made.Sleep initiation and maintenance tended to improve with A-MQD as demonstrated by the increases in TST and SE and decreases in WASO and NAW as compared with placebo-baseline values. Sleep architecture was preserved by the study drug and some increases in stage 2 and 3/4 sleep were seen compared with placebo baseline. Subjective ratings of sleep quality and sleep time were significantly improved with treatment, as were BPI scores and ratings of medication acceptance and pain relief. A-MQD was generally well tolerated.A-MQD was an effective treatment for pain, and this study treatment was associated with improvement of both objective and subjective sleep parameters in participants with chronic osteoarthritic pain.

This multicenter trial compared the efficacy, safety, and effect on quality of life and work limitation of once-daily extended-release morphine sulfate capsules (AVINZA, A-MQD) and twice-daily controlled-release oxycodone HCI tablets (OxyContin, O-ER) in subjects with chronic, moderate to severe low back pain. After randomization and a period of opioid dose titration, subjects (n=266) underwent an eight-week evaluation phase and an optionalf our-month extension phase (n=174 in extension phase). Subjects were assessed using the 12-item Short-Form Health Survey (SF-12) and the Work Limitations Questionnaire (WLQ). In both groups, significant improvements were observed in the SF-12 mean scores forp hysicalf unctioning (p < 0.001), role physical (p < 0.0001), bodilyp ain (p < 0.0001), physical summary (p < 0.001), and mental component summary (p < 0.005). At the end of the titration period, greater relative improvements from baseline were seen in the SF-12 section on physical components in the A-MQD group versus the O-ER group, with significant differences observed for physical functioning (p = 0.0374), role physical (p = 0.0341), bodily pain (p = 0.0001), andp hysical summary (p = 0.0022). In both groups, SF-12 mean scores improved significantly for mental health (p < 0.01), role emotional (p < 0.01), socialfunctioning (p < 0.0005), vitality (p < 0.005), and the mental component summary (p < 0.005), but no significant differences were noted between the two groups. Both groups reported improvement from baseline in WLQ physical demands scores, with no significant differences noted between the two groups. At the end of the evaluation phase, fewer subjects were unable to work due to illness or treatment in the A-MQD group than in the O-ER group (8.5 percent versus 19.4 percent, respectively; p = 0.0149). In conclusion, compared to twice-daily OxyContin, once-daily A VINZA resulted in significantly better and earlier improvement ofp hysicalf unction and ability to work.

STUDY DESIGN

AND

OBJECTIVE:

The ACTION trial, an open-label, randomized, multicenter, two-part study, compared the efficacy and safety of two sustained-release opioids (SROs), A VINZA (A-MQD), morphine sulfate extended-release capsules given once a day, and OxyContin (O-ER), oxycodone modified-release tablets given twice a day, in subjects with chronic, moderate to severe low back pain. The first part of the study, the evaluation phase, was followed by an optional four-month extension phase aimed at evaluating the long-term stability of pain control, SRO dose, and quality of sleep.

RESULTS:

Three hundred and ninety-two subjects were enrolled in the study; 220 completed the evaluation phase, and 174 entered the extensionphase. During the latterphase, subjects in the A-MQD group (n=79) continued to report lower pain scores, better quality of sleep, lower daily morphine-equivalent doses (means of 86 mg versus 119 mg), and a comparable usage of ibuprofen compared to subjects in the O-ER group (n=95). The incidence and severity of elicited opioid side effects were similar between the two groups.

CONCLUSIONS:

Both study drugs resulted in significant pain relief and improved sleep in SRO-naive patients with chronic low back pain, and this outcome was attained with a stable daily SRO dose. In patients who completed opioid dose titration, A VINZA performed significantly better than OxyContin in reducing pain scores and improving sleep-with a lower morphine-equivalent daily dose-during both the evaluation and extension phases.

This large, open-label, randomized, parallel-group, multicenter study compared two oral sustained-release opioids (SROs)--AVINZA (A-MQD), morphine sulfate extended-release capsules given once a day, and OxyContin (O-ER), oxycodone modified-release tablets given twice a day--in SRO-naive subjects ages 30 to 70 with chronic, moderate to severe low back pain. Of the 392 subjects enrolled and randomized, 266 (132 in the A-MQD group and 134 in the O-ER group) completed the opioid dose titration phase and entered an eight-week evaluation phase. During the evaluation phase, A-MQD achieved significantly better pain control than O-ER, as demonstrated by a greater decrease from baseline in pain scores obtained four times daily during weeks one, four, and eight (p = 0.002). The number of breakthrough-pain rescue medication doses adjusted for the number of patient days was significantly lower in the A-MQD group (p < 0.0001). Better pain control with A-MQD was achieved with a significantly lower daily opioid dose than with O-ER (mean 69.9 mg and 91 mg morphine equivalents, respectively; p = 0.0125). Quality of sleep was significantly better with A-MQD for the entire evaluation phase (p = 0.0026). The incidence and severity of elicited opioid side effects were similar in the two groups. This trial demonstrated that once-daily A-MQD provides consistent around-the-clock pain relief in patients with low back pain. In patients who completed opioid dose titration, A-MQD was significantly better than O-ER for reducing pain and improving sleep, while requiring a lower daily opioid dose.

This study evaluated the clinical effects and pattern of use of AVINZA((r)), morphine sulfate extended-release tablets, under real-world treatment conditions. Opioid-naive subjects or subjects who have failed other opioids were eligible if they had chronic moderate-to-severe noncancer pain with an average pain score > or =4 (0-10 scale) in the preceding month. Subjects answered in-depth monthly questionnaires in three months. For the 491 evaluable subjects enrolled, the median AVINZA dose was 30 mg at baseline, titrated to 60 mg by month 1, and remained at 60 mg through month 3. Adherence was high, with almost 90% of the subjects reporting never having forgotten to take AVINZA. Mean daily pain scores (scale 0-10) significantly improved from 7.83 at enrollment to 5.77 at month 1 (P < 0.01) and then remained at this level through month 3. Significant improvements were seen in all sleep measures, and the mean Composite Sleep Score, a global measure of sleep quality (scale 0-10), significantly improved from 5.73 at baseline to 4.96 at month 3 (P < 0.01). Physical functioning was improved for activities requiring a moderate effort (P = 0.053), such as climbing one flight of stairs (P = 0.008). Two hospitalizations for nausea and vomiting were the only reported drug-related serious adverse events. This study showed that once-daily AVINZA significantly reduced pain scores, and resulted in improved sleep and physical functioning in patients with chronic moderate-to-severe pain. These results were achieved with a stable daily morphine dose over the three-month study period.

Avinza is a once-daily, extended-release oral morphine preparation. It has a pharmacokinetic profile that exhibits less peak-to-trough fluctuations in plasma concentration whilst providing analgesia statistically identical to that produced by MS Contin (controlled-release morphine sulfate), Oxycontin (oxycodone HCl controlled-release) and six doses of oral morphine sulfate administered every 4 h. Avinza improves quality of sleep by several measures but interestingly gives the best sleep improvement when given in the morning rather than at night. It causes the same side effects of other opioids: constipation, nausea, vomiting, somnolence and mood swings. Doses of 30 - 60 mg/day have been shown to be well tolerated by patients with osteoarthritis (even in the elderly), who have failed other medications.