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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Morphine, the principal alkaloid of "papaver somniferum" is the reference substance of central analgesics, the parmacodynamic constants of which are: analgesia and the possibility of addiction. Respiratory depression is, for many of them, a grave side-effect. At the present time, no substance in this category is fully satisfactory and all may result in dependence. Equi-analgesic doses of dextromoramide, phenoperidine and Fentanyl are less than those of morphine, whilst those of pethidine and pentazocine are higher. Study of the pharmacokinetics of these various substances indicates no common elements, and it is difficult to consider that the analgesic action is proportional to blood levels. Clinical assessment of the mean duration of action makes it possible to divide morphine derivatives into substances with a very short action (20 to 45 minutes) such as Febtanyl and phenoperidine, and those with a longer action (1 to 4 hours) which includes the majority of the other substances. The analgesic activity of Methoadone lasts for 4 to 6 hours. Morphine antagonists such as Methadone, nalophine, naloxone and naltrexone possess specific problems in terms of their utilization. Pharmacological data concerning theses substances are described.
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PMID:[Pharmacology of morphine and its derivatives (review)]. 2 28

This double-blind randomised study compared postoperative analgesia after a loading regimen of methadone or morphine in thirty women undergoing abdominal hysterectomy. Methadone or morphine, 0.25 mg.kg-1, was given intravenously at induction of anaesthesia with further increments in the recovery room for analgesia if required. The mean (SD) total doses of methadone and morphine required were 0.43 (0.13) mg.kg-1 and 0.45 (0.15) mg.kg-1 respectively. Patients in the methadone group had lower pain scores in the subsequent 48 hours (P less than 0.001) and required less supplementary intramuscular opioids (P less than 0.001). Ten patients in the methadone group did not request any further opioid analgesics while all patients in the morphine group made at least two requests for opioids. The overall postoperative course was remembered as less painful by patients in the methadone group (P less than 0.001). There was no significant respiratory depression or excessive sedation in either group.
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PMID:A double-blind randomised trial comparing postoperative analgesia after perioperative loading doses of methadone or morphine. 160 41

Combined spinal and epidural anesthesia is a new regional anesthetic modality which combines the benefits of both the spinal and epidural approaches. 24 patients (11 after cesarean section and 13 after orthopedic operations on the lower limbs) were studied. Muscle relaxation and anesthesia were excellent, and regional anesthesia can be prolonged after the original spinal anesthesia wears off. No other anesthetics were needed. Methadone or morphine were given through the epidural catheter in the recovery room for postoperative analgesia. All patients were followed for 24 hours postoperatively.
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PMID:[Combined spinal-epidural anesthesia]. 206 21

The analgesic and adverse effects of intrathecal methadone 5 mg, 10 mg and 20 mg were assessed and compared with intrathecal morphine 0.5 mg. The study was conducted on 38 patients who underwent total knee or hip replacement surgery. The intrathecal opioid was administered at the end of surgery and assessments began 1 h thereafter and continued for 24 h. Pain measurements, supplementary analgesia requirements, and adverse effects were recorded. Intrathecal morphine 0.5 mg provided effective and prolonged analgesia. Intrathecal methadone 5 mg, 10 mg, and 20 mg produced good analgesia of 4 h duration. Thereafter the median pain scores with intrathecal methadone were consistently higher (worse) than those with intrathecal morphine (P less than 0.05). The time to the onset of discomfort severe enough to require supplemental morphine was longer after intrathecal morphine than following methadone (15 h with morphine 0.5 mg; 6.25 h, 6.5 h and 6 h with methadone 5 mg, 10 mg, and 20 mg respectively: P less than 0.05). Central nervous system depression manifesting as respiratory depression, hypotension, and excessive drowsiness occurred in 3 of 8 patients injected with methadone 20 mg intrathecally. Generalized pruritus, nausea, vomiting, and urinary retention were common and equally distributed among the treatment groups. We conclude that both intrathecal morphine 0.5 mg and methadone 5, 10, and 20 mg provide excellent analgesia but that morphine has a more prolonged effect. Methadone 20 mg produced unacceptable side effects. Clinical evidence for rostral spread of methadone within the CSF, as indicated by facial itching and excessive drowsiness, was less apparent with 5 mg than with 10 and 20 mg. Various explanations for the observed differences between the drugs are discussed.
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PMID:Intrathecal methadone: a dose-response study and comparison with intrathecal morphine 0.5 mg. 208 26

Methadone, a potent long-acting opioid analgesic, is only seldom prescribed for postoperative pain relief in Germany. It was the aim of the present investigation to evaluate its efficacy and to establish an adequate dose range using intravenous patient-controlled analgesia (PCA), as well as to determine possible drug interactions with the antipyretic analgesic metamizol (dipyrone). 120 patients recovering from elective major abdominal, gynaecological or orthopaedic surgery under standardized balanced anaesthesia were randomly allocated to three groups to self-administer intravenous 1-methadone. Demand doses were 0.573 mg (group LD), 1.145 mg (group HD) or 0.573 mg to which 50 mg metamizol (dipyrone) were added (group LM). Infusion rate was set to 0.137 mg 1-methadone/h in every group, lockout time was 1 min. Hourly maximum dose was set to 5.95 mg 1-methadone/h. During an average PCA duration of 21 hours patients demanded mean dosages of 16.4 mg (LD), 18.7 mg (HD) or 13.4 mg (LM) 1-methadone. Although individual variation in drug consumption was high, effective pain relief was possible in all cases. Cardiovascular and respiratory status during the observation period was always normal. 88-93% of patients preferred PCA in comparison with earlier experienced conventional postoperative pain treatment. It is concluded that patients are able to control adequate drug consumption, i.e. to avoid overdosage, by adjusting demand frequency if variable demand dosages are offered. Thus 13-19 mg 1-methadone per day can be recommended as reasonable dose range for pain relief during the early postoperative period.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Postoperative pain therapy with 1-methadone and metamizole. A randomized study within the scope of intravenous on-demand analgesia]. 219 55

The analgesic characteristics of 3 to 6 mg epidural methadone administered in two different concentrations for postoperative analgesia have been compared in two homogeneous groups of patients submitted to surgical procedures on trunk or legs. Methadone was given at a concentration of 0.1% in group I (70 patients) and diluted in 10 ml saline in group II (35 patients). Methadone doses were calculated on the basis of age and weight of the patient and the performed surgical procedure. Mean latency for analgesia was 25 +/- 11 min in group I and 28 +/- 13 min in group II. The duration of the analgesia was significantly longer (p less than 0.01) in group I (9.7 +/- 5.6 h) than in group II (5.7 +/- 2.4 h). Side effects were not frequent and without clinical significance in both groups. Epidural methadone is an effective method for postoperative pain relief. Drug concentration modifies the duration of the analgesia and concentration of 0.1% gives better results than more diluted preparations.
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PMID:[Effect of the peridural methadone concentration in postoperative analgesia]. 259 59

A double-blind study of patients selected at random compared the analgesic and adverse effects of intrathecal methadone (1 mg) with those of intrathecal morphine (0.5 and 1 mg). The study was conducted on 30 patients who underwent major orthopedic or urologic surgery. The intrathecal opioid was administered at the end of surgery, and assessments began 1 h thereafter and continued for 20 h. Pain measurements, supplementary analgesia requirements, and adverse effects were recorded. Intrathecal morphine (0.5 and 1 mg) provided effective and prolonged analgesia. Methadone, however, was unable to ensure the same degree of analgesia; consequently, the median pain scores were consistently higher following methadone than morphine (0.5 and 1 mg) (P less than 0.05). The time to the onset of discomfort severe enough to require supplemental morphine was longer after intrathecal morphine than that following methadone (24 and 29 h with morphine 0.5 and 1 mg; 6.5 h with methadone; P less than 0.05). Respiratory depression (increases PaCO2) was not associated with methadone and morphine 0.5 mg but was common following morphine 1 mg (P less than 0.05). Facial pruritus was unique to intrathecal morphine. Urinary retention requiring bladder catheterization was more frequent following morphine than methadone, although this was not statistically significant. Nausea and vomiting were common to all groups. Intrathecal morphine (0.5 and 1 mg) provides superior postoperative analgesia to 1 mg methadone. Various explanations for the observed differences between the drugs are discussed, including the possibility that the dose of methadone used in the subarachnoid space was inadequate and that a larger dose might have produced an effect equal to that of morphine.
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PMID:Intrathecal methadone and morphine for postoperative analgesia: a comparison of the efficacy, duration, and side effects. 235 28

In order to find a suitable analgesic for the treatment of postoperative pain in pigs the analgesic effect of buprenorphine, etorphine and pethidine has been compared in 8 domestic pigs. For assessment of the analgesic action on thermal (hot plate) and two mechanical (cannulation of ear vein, needle prick) noxious stimuli have been employed. In a pilot experiment on 2 pigs in which methadone was included the maximal effective doses were estimated for each drug. Methadone was found unsuitable because of unacceptable side effects (respiratory dysfunction, hyperactivity) at effective dose levels. Next buprenorphine 120 micrograms/kg, etorphine 3 micrograms/kg and pethidine 20 mg/kg all given intramuscularly were compared in a randomized blind trial with a balanced cross-over design on 6 pigs. Etorphine proved to have the highest and pethidine the lowest maximal analgesic effect which was especially evident in the needle-prick test. Buprenorphine proved to have the longest duration of action in all three analgesic tests, in the hot plate test lasting between 7 and 24 hrs. Etorphine had a duration of 3 to 5 hrs whereas the effect of pethidine was short, only lasting about 2 hrs. Etorphine provides a complete analgesia but has a small safety margin for which reason it should be used with caution in the pig. The experimental results indicate that buprenorphine should be the first drug of choice in the treatment of pain after surgical intervention due to its long duration of action and lack of side effects.
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PMID:The analgesic effect of buprenorphine, etorphine and pethidine in the pig: a randomized double blind cross-over study. 376 47

Activity of opioids in cats was assessed by employing the tail-flick method. Microinjection of morphine (100 micrograms) or etorphine (2.5 micrograms) into the ventrolateral periaqueductal gray (VLPAG) region resulted in significant analgesia. Smaller doses of morphine (10 and 50 micrograms) or etorphine (0.62 and 1.25 micrograms) were without significant effect. Methadone likewise produced no significant analgesic action in doses as large as 360 micrograms in the ventrolateral periaqueductal gray. Rank order potency, i.e. etorphine greater than morphine much greater than methadone, was similar following systemic administration. Increased latency of tail-flick response after injection of etorphine was diminished by administration of naloxone, either systemically or centrally, thus indicating a specific opiate-mediated response.
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PMID:Feline analgesia following central administration of opioids. 648 17

A 59-year-old woman with metastatic breast cancer experienced a poor response to increasing doses of hydromorphone, possibly related to the neuropathic nature of her pain. Ultimately, the cost of this treatment was more than $1000 per day. Administration of methadone, initially as an adjuvant and eventually as the sole analgesic, at a much smaller dose than expected resulted in very satisfactory analgesia, without the development of serious side effects. In addition, the cost of treatment decreased to less than $25 per day. This case illustrates the rationale and advantages for the use of methadone. Intraindividual variability in the response to various opioids is a factor to be considered when selecting analgesics. Methadone is a useful second-line or third-line opioid for the patient who is highly tolerant to other opioids, as it may demonstrate incomplete cross-tolerance with other agonist opioids. Switching of the opioid to methadone may be a worthwhile option to consider in managing patients who are highly tolerant to other opioids.
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PMID:Use of methadone in a highly tolerant patient receiving parenteral hydromorphone. 754 38


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