In spite of challenges related to the variable pharmacokinetics and concerns regarding increase in QTc time, current evidence indicates that opioid switching to methadone improves pain control in a substantial proportion of patients who are candidates for opioid switching. Measures must be instituted to secure that patients receiving methadone for pain are not considered opioid addicts.

No abstract

According to a Cochrane review on opioid switching, sound evidence on the practice of substituting one strong opioid with another to improve pain control and reduce adverse effects was lacking in 2004. A systematic search strategy was developed to include studies after 2004, with adult cancer patients switching between strong opioids and reporting estimates of effect on pain and adverse effects. The search retrieved 288 publications (71 duplicates); 187 abstracts and 19 full papers were excluded. Eleven papers met the inclusion criteria; none were randomized controlled trials/meta-analyses. Studies comprised 280 patients (group size 10-32). A variety of opioids and switching strategies were studied. Pain intensity was significantly reduced in the majority of studies. Serious adverse effects were improved. Due to serious design limitations, the level of evidence was low (D). Randomized trials, with standardization of cohort classification, use of outcomes and analysis are warranted to establish the practice of opioid switching.

A total of 115 elderly patients (60-85 years of age) with DSM III diagnosis of major depressive episode were randomly assigned to 6 weeks of treatment with either mirtazapine, 15-45 mg/day, or amitriptyline, 30-90 mg/day. Efficacy was assessed biweekly, using the Hamilton Rating Scale for Depression (HRSD) and Montgomery and Asberg Depression Rating Scale (MADRS) as primary outcome variables. The treatment with both drugs resulted in a similar reduction of total HRDS and MADRS scores, with no statistically significant differences between treatment groups at any assessment point or at endpoint. Statistically significant differences favouring amitriptyline were present according to CGI-Global Improvement Scale at endpoint, HRDS cognitive disturbance factor at weeks 2, 4 and 6 and endpoint and retardation factor at week 6. Adverse events were reported by a similar number of patients in both treatment groups. Additional research is needed to assess further the efficacy and tolerability of mirtazapine among elderly depressed patients.