Opioid analgesic: Difference between revisions
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===Tolerance=== | ===Tolerance=== | ||
[[N-methyl-d-aspartate receptor]] activation may lead to neuropathic pain and tolerance.<ref name="pmid1824728">{{cite journal| author=Trujillo KA, Akil H| title=Inhibition of morphine tolerance and dependence by the NMDA receptor antagonist MK-801. | journal=Science | year= 1991 | volume= 251 | issue= 4989 | pages= 85-7 | pmid=1824728 | [[N-methyl-d-aspartate receptor]] (NMDA) activation may lead to neuropathic pain and tolerance.<ref name="pmid1824728">{{cite journal| author=Trujillo KA, Akil H| title=Inhibition of morphine tolerance and dependence by the NMDA receptor antagonist MK-801. | journal=Science | year= 1991 | volume= 251 | issue= 4989 | pages= 85-7 | pmid=1824728 | ||
| url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=1824728 }} <!--Formatted by http://sumsearch.uthscsa.edu/cite/--></ref><ref name="pmid16629581">{{cite journal| author=Prommer E| title=Rotating methadone to other opioids: a lesson in the mechanisms of opioid tolerance and opioid-induced pain. | journal=J Palliat Med | year= 2006 | volume= 9 | issue= 2 | pages= 488-93 | pmid=16629581 | | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=1824728 }} <!--Formatted by http://sumsearch.uthscsa.edu/cite/--></ref><ref name="pmid16629581">{{cite journal| author=Prommer E| title=Rotating methadone to other opioids: a lesson in the mechanisms of opioid tolerance and opioid-induced pain. | journal=J Palliat Med | year= 2006 | volume= 9 | issue= 2 | pages= 488-93 | pmid=16629581 | ||
| url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=16629581 | doi=10.1089/jpm.2006.9.488 }} <!--Formatted by http://sumsearch.uthscsa.edu/cite/--></ref> [[Methadone]], which is a | | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=16629581 | doi=10.1089/jpm.2006.9.488 }} <!--Formatted by http://sumsearch.uthscsa.edu/cite/--></ref> [[Methadone]], which is a NMDA antagonist, may reduce tolerance. | ||
===Withdrawal=== | ===Withdrawal=== |
Revision as of 08:28, 14 January 2010
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Opioid analgesics, also called narcotics, are drugs usually used for treating pain. Opiod analgesics are defined as "all of the natural and semisynthetic alkaloid derivatives from opium, their pharmacologically similar synthetic surrogates, as well as all other compounds whose opioid-like actions are blocked by the nonselective opioid receptor antagonist naloxone.[1]
Pharmacology
There a several opioid receptors. All are are G-protein-coupled cell surface receptors.
- Mu receptors are responsible for analgesia.
- Delta
- Kappa
Clinically useful analgesic families vary in their receptor effects; they range from pure agonists of all receptor types, to selective agonists, to agonist-antagonists.
Available opioid analgesics
Current opioid analgesics are below[2] Tables of morphine equivalent daily dose and IV to PO conversion are available to help dosing.[2]
- 18,19-dihydroetorphine
- Alfentanil
- Alphaprodine
- beta-casomorphins
- Buprenorphine
- Butorphanol
- carfentanil
- Codeine
- deltorphin I, Ala(2)-
- dermorphin
- Dextromoramide
- Dextropropoxyphene
- dezocine
- dihydrocodeine
- Dihydromorphine
- Diphenoxylate
- dynorphin (1-13)
- endomorphin 1
- endomorphin 2
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
- Enkephalin, D-Penicillamine (2,5)-
- enkephalin-Met, Ala(2)-
- eseroline
- Ethylketocyclazocine
- Ethylmorphine
- Etorphine
- Fentanyl
- Heroin
- Hydrocodone
- Hydromorphone
- ketobemidone
- Levorphanol
- lofentanil
- Meperidine
- Meptazinol
- Methadone
- Methadyl Acetate
- Morphine
- Nalbuphine
- nocistatin
- Opiate Alkaloids
- Opium
- Oxycodone
- Oxymorphone
- paracymethadol
- Pentazocine
- Phenazocine
- Phenoperidine
- Pirinitramide
- Promedol
- protopine
- remifentanil
- Sufentanil
- Tilidine
- tyrosyl-1,2,3,4-tetrahydro-3-isoquinolinecarbonyl-phenylalanyl-phenylalanine
Drugs that are both mu-opioid receptor agonists and norepinephrine reuptake inhibitors.
- Tapentadol
- Tramadol
Molecular class | Specific drug | Receptor action | Comments |
---|---|---|---|
Morphine | Morphine | row 1, cell 3 | |
Diacetylmorphine (heroin) | row 2, cell 2 | row 2, cell 3 | Faster blood-brain transfer than morphine but both produce the same primary active metabolite |
Effectiveness
Narcotics are commonly prescribed for pain, and their usage may be increasing.[3] In emergency rooms, non-Hispanic white patients are more likely to receive narcotics than patients of other ethnicities.[3]
Narcotics are effective for both short (1-16 weeks)[4] and long-term (6-24 months) use[5].
Narcotics, with long-term use, 80% of patients may have drug toxicity, most commonly gastrointestinal. In addition, substrance abuse and "aberrant medication-taking behaviors" may occur.[6] Advice for using administering chronic narcotics[7] and for treating acute pain among patients on chronic methadone is available[8].
Usage
Clinical practice guidelines are available.[9]
Tables of morphine equivalent daily dose and IV to PO conversion are available to help dosing.[2]
Adverse effects
Constipation
Constipation may be reduced by methylnaltrexone, a mu-opioid receptor antagonist. In a randomized controlled trial, 48% of patients receiving methylnaltrexone had a bowel movement compared to 15% of patients received placebo (number needed to treat = 3.0. Click here to adjust these results for patients at higher or lower risk.)[10] Although mu-receptors provide analgesia, methylnaltrexone is a charged quaternary amine so that it does not well cross the blood-brain barrier.
Tolerance
N-methyl-d-aspartate receptor (NMDA) activation may lead to neuropathic pain and tolerance.[11][12] Methadone, which is a NMDA antagonist, may reduce tolerance.
Withdrawal
Adding narcotic antagonists combined with alpha-adrenergic agonists may reduce withdrawal symptoms.[13]
References
- ↑ Katzung, Bertram G. (2006). Basic and clinical pharmacology. New York: McGraw-Hill Medical Publishing Division, 512. ISBN 0-07-145153-6.
- ↑ 2.0 2.1 2.2 (2003) “78. Management of Cancer Pain”, Cancer medicine 6. Hamilton, Ont.: BC Decker. ISBN 1-55009-213-8.
- ↑ 3.0 3.1 Pletcher MJ, Kertesz SG, Kohn MA, Gonzales R (2008). "Trends in opioid prescribing by race/ethnicity for patients seeking care in US emergency departments". JAMA 299 (1): 70–8. DOI:10.1001/jama.2007.64. PMID 18167408. Research Blogging.
- ↑ Furlan AD, Sandoval JA, Mailis-Gagnon A, Tunks E (2006). "Opioids for chronic noncancer pain: a meta-analysis of effectiveness and side effects". CMAJ 174 (11): 1589–94. DOI:10.1503/cmaj.051528. PMID 16717269. Research Blogging.
- ↑ Kalso E, Edwards JE, Moore RA, McQuay HJ (2004). "Opioids in chronic non-cancer pain: systematic review of efficacy and safety". Pain 112 (3): 372–80. DOI:10.1016/j.pain.2004.09.019. PMID 15561393. Research Blogging.
- ↑ Martell BA, O'Connor PG, Kerns RD, et al (2007). "Systematic review: opioid treatment for chronic back pain: prevalence, efficacy, and association with addiction". Ann. Intern. Med. 146 (2): 116–27. PMID 17227935. [e]
- ↑ Clinical Guidelines for the Use of Chronic Opioid Therapy in Chronic Noncancer Pain Roger Chou, Gilbert J. Fanciullo, Perry G. Fine, Jeremy A. Adler, Jane C. Ballantyne, Pamela Davies, Marilee I. Donovan, David A. Fishbain, Kathy M. Foley, Jeffrey Fudin, Aaron M. Gilson, Alexander Kelter, Alexander Mauskop, Patrick G. O'Connor, Steven D. Passik, Gavril W. Pasternak, Russell K. Portenoy, Ben A. Rich, Richard G. Roberts, Knox H. Todd, Christine Miaskowski, American Pain Society–American Academy of Pain Medicine Opioids Guidelines Panel The Journal of Pain - February 2009 (Vol. 10, Issue 2, Pages 113-130.e22,( DOI:10.1016/j.jpain.2008.10.008)
- ↑ Alford DP, Compton P, Samet JH (2006). "Acute pain management for patients receiving maintenance methadone or buprenorphine therapy". Ann. Intern. Med. 144 (2): 127–34. PMID 16418412. [e]
- ↑ Chou R, Fanciullo GJ, Fine PG, Adler JA, Ballantyne JC, Davies P et al. (2009). "Clinical guidelines for the use of chronic opioid therapy in chronic noncancer pain.". J Pain 10 (2): 113-30. DOI:10.1016/j.jpain.2008.10.008. PMID 19187889. Research Blogging.
- ↑ Thomas J, Karver S, Cooney GA, Chamberlain BH, Watt CK, Slatkin NE, Stambler N, Kremer AB, Israel RJ. Methylnaltrexone for opioid-induced constipation in advanced illness. N Engl J Med. 2008 May 29;358(22):2332-43. PMID 18509120
- ↑ Trujillo KA, Akil H (1991). "Inhibition of morphine tolerance and dependence by the NMDA receptor antagonist MK-801.". Science 251 (4989): 85-7. PMID 1824728.
- ↑ Prommer E (2006). "Rotating methadone to other opioids: a lesson in the mechanisms of opioid tolerance and opioid-induced pain.". J Palliat Med 9 (2): 488-93. DOI:10.1089/jpm.2006.9.488. PMID 16629581. Research Blogging.
- ↑ Gowing L, Ali R, White JM (2009). "Opioid antagonists with minimal sedation for opioid withdrawal.". Cochrane Database Syst Rev (4): CD002021. DOI:10.1002/14651858.CD002021.pub3. PMID 19821290. Research Blogging.