Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2001-2-22
pubmed:abstractText
Opioid substitution treatment for dependence may alter sensitivity to pain. Previous studies on pain sensitivity in methadone maintenance patients have yielded contradictory results. This study compared nociceptive responses between 16 patients on stable, once daily, doses of methadone and 16 matched control subjects. Two types of nociceptive stimuli were used: (1) electrical stimulation; and (2) a cold pressor test. Two parameters were measured: detection for onset of pain, and pain tolerance. Methadone patients were tested over an inter-dosing period: at the time of trough plasma methadone concentration (0 h), and 3 h after their daily dose. Control subjects were tested twice 3 h apart. Blood samples were collected to determine plasma methadone concentration. In methadone patients, trough to peak increases in mean R-(-)- and S-(+)-methadone concentrations (118 and 138 ng/ml to 185 and 259 ng/ml, respectively) resulted in significant increases in pain detection and tolerance values for both nociceptive stimuli. Using electrical stimulation, methadone patients' pain tolerance values were lower than controls at 0 h, but higher than controls at 3 h; no significant differences in pain detection values were found. For the cold pressor test, methadone patients detected pain significantly earlier than controls at 0 h, and were also substantially less pain tolerant than controls at both 0 and 3 h. There were no significant differences in pain detection values between the two groups at 3 h. Pain tolerance to pain detection ratios for methadone patients were significantly lower than controls for the cold pressor test at 0 and 3 h, and for electrical stimulation at 0 h only. In summary, the relative pain sensitivity of methadone maintenance patients is determined by the nature of the nociceptive stimulus (e.g. cold pressor test versus electrical stimulation), the plasma methadone concentration (trough versus peak plasma concentration), and whether thresholds are determined for detection of pain or pain tolerance. Although responding to changes in plasma methadone concentration, maintenance patients are markedly hyperalgesic to pain induced by the cold pressor test.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0304-3959
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
90
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
91-6
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Hyperalgesic responses in methadone maintenance patients.
pubmed:affiliation
Department of Clinical and Experimental Pharmacology, University of Adelaide, SA 5005, Adelaide, Australia. mark.doverty@adelaide.edu.au
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, U.S. Gov't, P.H.S., Controlled Clinical Trial, Research Support, Non-U.S. Gov't