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Oral Methadone (oral + methadone)
Selected AbstractsPharmacokinetics of the injectable formulation of methadone hydrochloride administered orally in horsesJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2009R. L. LINARDI Methadone hydrochloride is a synthetic ,-opioid receptor agonist with potent analgesic properties. Oral methadone has been successfully used in human medicine and may overcome some limitations of other analgesics in equine species for producing analgesia with minimal adverse effects. However, there are no studies describing the pharmacokinetics (PK) of oral opioids in horses. The aim of this study was to describe the PK of orally administered methadone (0.1, 0.2 and 0.4 mg/kg) and physical effects in 12 healthy adult horses. Serum methadone concentrations were measured by gas chromatography/mass spectrometry at predetermined time points for 24 h, and PK parameters were estimated using a noncompartmental model. Physical effects were observed and recorded by experienced clinicians. No drug toxicity, behavioural or adverse effects were observed in the horses. The disposition of methadone followed first order elimination and a biphasic serum profile with rapid absorption and elimination phases. The PK profile of methadone was characterized by high clearance (Cl/F), small volume of distribution (Vd/F) and short elimination half-life (t1/2). The mean of the estimated t1/2 (SD) for each dose (0.1, 0.2 and 0.4 mg/kg) was 2.2 (35.6), 1.3 (46.1) and 1.5 (40.8), and the mean for the estimated Cmax (SD) was 33.9 (6.7), 127.9 (36.0) and 193.5 (65.8) respectively. [source] Heroin-assisted treatment in Switzerland: a case study in policy changeADDICTION, Issue 1 2010Ambros Uchtenhagen ABSTRACT Background Switzerland introduced a pragmatic national drug policy when the former conservative abstinence-orientated politics proved unable to cope with an escalating number of users and related negative consequences for public health and public order. The high visibility of ,needle parks' and the size of the acquired immune deficiency disorder (AIDS) epidemic called for a new approach and for national leadership. Aims To describe the intentions, the process and the results of setting up the new treatment approach of prescribing heroin to treatment resistant heroin addicts, as an example of drug policy change. Materials and Methods A systematic collection of relevant documents is analysed and used as evidence for describing the process of policy change. Results Measures to reduce the negative consequences of continued use and to prevent the spread of AIDS were started mainly by private initiatives and soon taken up officially in the ,four-pillar' drug policy (including harm reduction, prevention, treatment and law enforcement). Medical prescription of heroin to chronic, treatment-resistant heroin addicts was one of the innovations, based on extensive scientific and political preparation. Detailed documentation and evaluation, ample communication of results, adaptations made on the basis of results and extensive public debate helped to consolidate the new policy and heroin-assisted treatment, in spite of its limitations as an observational cohort study. All necessary steps were taken to proceed from a scientific experiment to a routine procedure. Discussion Comparable policy changes have been observed in a few other countries, such as The Netherlands and Germany, based on the Swiss experience, with equally positive results of heroin-assisted treatment. These experiments were designed as randomised controlled trials, comparing intravenous heroin against oral methadone, thereby demonstrating the specific value of pharmaceutical diamorphine for maintenance treatment in opiate dependence. The positive impact of policy change and the positive outcomes of heroin-assisted treatment were acknowledged increasingly nationally and internationally, but made it difficult to continue the process of adapting policy to new challenges, due to the low visibility of present drug problems and to changing political priorities. Conclusion A major change in drug policy was effectively realised under typical conditions of a federalist country with a longstanding tradition of democratic consensus building. Facilitating factors were the size and visibility of the heroin problem, the rise of the Aids epidemic, and a pragmatic attitude of tolerating private initiatives opening the way to official policy change. [source] Transdermal Fentanyl: Little Absorption in Two Patients with Systemic Sclerosis?PAIN MEDICINE, Issue 3 2001Matthias Karst MD Two patients suffering from systemic sclerosis (SSc) were treated with the 25 ,/hr transdermal fentanyl patch for pain from either deltoid muscle tendinitis of the left arm or from ischemia of the left-hand thumb. When the medication was changed to either oral morphine or oral methadone, the effects did not correspond to the drug conversion table. These findings suggest that patients with SSc and other systemic skin diseases may be at risk for limited absorption of transdermal fentanyl. In contrast, no restriction of the absorption of transdermal testosterone was observed. [source] Opioid switching from transdermal fentanyl to oral methadone in patients with cancer painCANCER, Issue 12 2004Miguel Angel Benítez-Rosario M.D., Ph.D. Abstract BACKGROUND Patients with cancer often are rotated from other opioids to methadone to improve the balance between analgesia and side effects. To the authors' knowledge, no clear guidelines currently exist for the safe and effective rotation from transdermal fentanyl to methadone. METHODS The authors evaluated a protocol for switching opioid from transdermal fentanyl to oral methadone in 17 patients with cancer. Reasons for switching were uncontrolled pain (41.1% of patients) and neurotoxic side effects (58.9% of patients). Methadone was initiated 8,24 hours after fentanyl withdrawal, depending on the patient's previous opioid doses (from < 100 ,g per hour to > 300 ,g per hour). The starting methadone dose was calculated according to a 2-step conversion between transdermal fentanyl:oral morphine (1:100 ratio) and oral morphine:oral methadone (5:1 ratio or 10:1 ratio). The correlation between previous fentanyl dose and the final methadone dose or the fentanyl:methadone dose ratio was assessed by means of Pearson and Spearman correlation coefficients (r), respectively. A Friedman test was used to compare pain intensity before and after the switch and the use of daily rescue doses. RESULTS Opioid rotation was fully or partially effective in 80% and 20%, respectively, of patients with somatic pain. Neuropathic pain was not affected by opioid switching. Delirium and myoclonus were reverted in 80% and 100% of patients, respectively, after opioid switching. A positive linear correlation was obtained between the fentanyl and methadone doses (Pearson r, 0.851). Previous fentanyl doses were not correlated with the final fentanyl:methadone dose ratios (Spearman r, , 0.327). CONCLUSIONS The protocol studied provided a safe approach for switching from transdermal fentanyl to oral methadone, improving the balance between analgesia and side effects in patients with cancer. Cancer 2004. © 2004 American Cancer Society. [source] | ||||||||||