Opioid switching from oral slow release morphine to oral methadone may improve pain control in chronic non-malignant pain: a nine-month follow-up study. Methadone versus morphine as a first-line strong opioid for cancer pain: a randomized, double-blind study. Low-dose methadone has an analgesic effect in neuropathic pain: a double-blind randomized controlled crossover trial. Does intravenous methadone provide longer lasting analgesia than intravenous morphine? A randomized, double-blind study. A comparative study of the efficacy and pharmacokinetics of oral methadone and morphine in the treatment of severe pain in patients with cancer. Comparative study of the effectiveness of slow-release morphine and methadone for opioid maintenance therapy. A double-blind, randomized, parallel group study to compare the efficacy, safety and tolerability of slow-release oral morphine versus methadone in opioid-dependent in-patients willing to undergo detoxification.
Twelve patients with poor pain control or unacceptable side effects during treatment with morphine were switched to methadone and followed for nine months in this open prospective study. Primary outcomes were patient preference for opioid and pain control while physical, cognitive and role functioning were secondary outcomes. The morphine dose was decreased by 1/3 daily and was replaced with an equianalgesic dose of methadone over a three-day period. During switching and a one-week dose titration period, patients were given additional methadone if required. During dose titration one patient experienced sedation requiring naloxone. Four patients were switched back to morphine due to poor pain control, drowsiness or sweating. Seven patients preferred long-term (>nine months) treatment with methadone and reported reduced pain and improved functioning while cognition was not improved. This study brings novel information on the long-term consequences for pain control, health-related quality of life and cognitive functioning with a switch from morphine to methadone in the treatment of chronic non-malignant pain. To compare the effectiveness and side effects of methadone and morphine as first-line treatment with opioids for cancer pain.
                Patients in international palliative care clinics with pain requiring initiation of strong opioids were randomly assigned to receive methadone (7.5 mg orally every 12 hours and 5 mg every 4 hours as needed) or morphine (15 mg sustained release every 12 hours and 5 mg every 4 hours as needed). The study duration was 4 weeks.
                A total of 103 patients were randomly assigned to treatment (49 in the methadone group and 54 in the morphine group). The groups had similar baseline scores for pain, sedation, nausea, confusion, and constipation. Patients receiving methadone had more opioid-related drop-outs (11 of 49; 22%) than those receiving morphine (three of 54; 6%; P =.019). The opioid escalation index at days 14 and 28 was similar between the two groups. More than three fourths of patients in each group reported a 20% or more reduction in pain intensity by day 8. The proportion of patients with a 20% or more improvement in pain at 4 weeks in the methadone group was 0.49 (95% CI, 0.34 to 0.64) and was similar in the morphine group (0.56; 95% CI, 0.41 to 0.70). The rates of patient-reported global benefit were nearly identical to the pain response rates and did not differ between the treatment groups.
                Methadone did not produce superior analgesic efficiency or overall tolerability at 4 weeks compared with morphine as a first-line strong opioid for the treatment of cancer pain. The analgesic effectiveness and adverse effect incidence of a daily dose of 10 or 20 mg of oral methadone were evaluated in 18 patients with a diverse range of chronic neuropathic pain syndromes, who had all responded poorly to traditional analgesic regimens. Analgesia was seen after each dose of methadone. As compared with placebo, the 20 mg daily dose (given as 10 mg bd) resulted in statistically significant (P = 0.013-0.020) improvements in patient Visual Analogue Scale ratings of maximum pain intensity, average pain intensity and pain relief, recorded at the same time daily. The analgesic effects extended over 48 hours, as shown by statistically significant (P = 0.013-0.020) improvements in all three outcomes on the rest days instituted between each daily dose. Analgesic effects (lowered maximum pain intensity and increased pain relief, on the day of dosing only) were also seen when the lower daily dose of 10 mg methadone (given as 5 mg bd) was used, but these failed to reach statistical significance (P = 0.064 and 0.065, respectively). Interpatient analysis showed that the analgesic effects were not restricted to any particular type of neuropathic pain. Patient compliance was high throughout the trial. One patient withdrew during the 10 mg and six during the 20 mg methadone treatment periods. This is the first double-blind randomized controlled trial to demonstrate that methadone has an analgesic effect in neuropathic pain. A prospective, randomized, double-blind trial was designed to compare the duration of analgesia produced by intravenous morphine and methadone. Patients with intractable cancer-related pain were studied for 5-6 days. One-eighth of the patient's daily opiate requirement was supplied as an i.v. infusion of either morphine or methadone over a period of 15 min. when initiated by the patient using a patient-controlled analgesia device. Dosing intervals, pain intensity assessments and toxicity were evaluated. Twenty-three patients were randomized; 18 were fully evaluable. Ten of the evaluable patients received morphine, 8 received methadone. Dosing intervals did not change over the 5 days for either group. The mean dosing interval for the last 10 doses was 3.9 +/- 0.85 h for patients receiving morphine and 3.9 +/- 1.6 h for patients receiving methadone (P = NS). One patient receiving morphine and one taking methadone required only 2-3 doses/day for pain control. Pain intensity and relief were similar for both groups. All patients had adequate analgesia as determined by at least a 50% difference in pain intensity at peak relief. The duration of pain relief when repeated intravenous doses of these analgesics were given was similar throughout the entire study period although morphine and methadone have different serum half-lives (3 vs. 25 h). Parenteral methadone does not offer a clinically significant increase in the duration of analgesia in patients with severe pain secondary to cancer. Eighteen patients suffering from cancer were entered into a study of the pharmacokinetics and efficacy of methadone and morphine in pain control. All patients had both clinical and radiological evidence of metastatic spread of their cancer and there were no significant differences in age, weight and sites of the primary cancer between the methadone (n = 9) and morphine (n = 9) groups. Blood opioid concentration, visual analogue pain scores (VAPS) and end-tidal percent carbon dioxide were measured before and after both an intravenous and oral dose of either methadone or morphine. Terminal half-lives (mean +/- S.D.) were 30.4 +/- 16.3 h and 2.7 +/- 1.2 h respectively for methadone and morphine while the clearance values (mean +/- S.D.) were 0.19 +/- 0.13 l/min and 1.16 +/- 0.47 l/min. The long half-life of methadone was associated with prolonged pain relief. However, the large variation in the half-life of methadone necessitated careful adjustment of the dosing interval in individual patients. There were pronounced differences in oral bioavailability between the two opioids: methadone, 79 +/- 11.7%, compared to morphine, 26 +/- 13% (mean +/- S.D.). Of greater clinical significance was the variability in these bioavailability estimates with a coefficient of variation of 15% for methadone compared to 50% for morphine. The combined effects of low and variable oral bioavailability for morphine may result in sub-therapeutic doses being administered as practitioners may be inhibited by the size of the effective oral morphine dose and may be confused by the variability in this dose compared to intramuscular doses. The initial oral dose of morphine varied from 15 mg 4 hourly to 150 mg 3 hourly, while the initial dose for methadone varied from 15 mg on alternate nights to 20 mg twice daily. There was no rapid escalation of daily opioid dose for either methadone or morphine when adequate pain control was provided rapidly at the start of treatment by the technique described in this study. Slow-release morphine may represent a much-needed new pharmacological treatment for opioid dependence.
                In a 14-week randomized, double-blind, double-dummy, cross-over study oral slow-release morphine was compared with methadone as a treatment for opioid dependency. During two study periods, each consisting of a 1-week titration and a 6-week fixed-dose treatment phase, medication was administered daily under supervised conditions.
                The study was carried out at the Addiction Clinic, Department of Psychiatry, Medical University Vienna.
                Sixty-four subjects (56 males, eight females) with opioid dependence participated in the trial.
                Efficacy was evaluated on the basis of retention, use of illicit substances based on urinalysis, extent of drug cravings, withdrawal symptoms and general wellbeing. Safety was assessed on the basis of adverse events and clinical and physical examination. Demographic and baseline characteristics were assessed using the European Addiction Severity Index.
                Fifty-five patients (86%) completed the study, with a mean methadone dose of 85 mg and a mean slow-release morphine dose of 680 mg. No significant differences in retention or use of illicit substances (opioids, benzodiazepines, cocaine) were observed, irrespective of treatment group or medication. However, patients receiving slow-release morphine had significantly lower depression (P < 0.001) and anxiety scores (P = 0.008) and fewer physical complaints (P < 0.001).
                Oral slow-release morphine is as effective as methadone in the treatment of opioid dependency, with comparable safety and tolerability and a greater benefit on patient wellbeing. Greater pharmaceutical diversity represents a modern development in mainstream medicine. Slow-release morphine might represent a future treatment option that will improve long-term outcomes for this target group. Evaluation of the efficacy and safety of slow-release oral morphine (SROM) compared with methadone for detoxification from methadone and SROM maintenance treatment.
                Randomized, double-blind, double-dummy, comparative multi-centre study with parallel groups.
                Three psychiatric hospitals in Austria specializing in in-patient detoxification.
                Male and female opioid dependents (age > 18 years) willing to undergo detoxification from maintenance therapy in order to reach abstinence.
                Abstinence was reached from maintenance treatment by tapered dose reduction of either SROM or methadone over a period of 16 days.
                Efficacy analyses were based on the number of patients per treatment group completing the study, as well as on the control of signs and symptoms of withdrawal [measured using Short Opioid Withdrawal Scale (SOWS)] and suppression of opiate craving. In addition, self-reported somatic and psychic symptoms (measured using Symptom Checklist SCL-90-R) were monitored.
                Of the 208 patients enrolled into the study, 202 were eligible for analysis (SROM: n = 102, methadone: n = 100). Completion rates were 51% in the SROM group and 49% in the methadone group [difference between groups: 2%; 95% confidence interval (CI): -12% to 16%]. The rate of discontinuation in the study was high mainly because of patients voluntarily withdrawing from treatment. No statistically significant differences between treatment groups were found in terms of signs and symptoms of opiate withdrawal, craving for opiates or self-reported symptoms. SROM and methadone were both well tolerated.
                Detoxification from maintenance treatment with tapered dose reduction of SROM is non-inferior to methadone.
The updated review contains new information supporting the previous conclusions that methadone has similar analgesic efficacy to morphine. The additional study examined neuropathic and non-neuropathic pain, finding no superiority for methadone in the former group. The new study also addresses a clinically relevant concern about short term/single dose studies. Use beyond a few days may result in methadone accumulation leading to delayed onset of adverse effects. In an assessment over 28 days there was a higher rate of withdrawal due to side effects in the methadone group. This observation reinforces the advice that experienced clinicians should take responsibility for initiation and careful dose adjustment and monitoring of methadone.