The Pharmacology of Opioids (DRAFT)

Author(s):  
Christopher Cavacuiti

This chapter focuses on the attributes of and component medications within the class of opioids, emphasizing kinetics, dynamics, and therapeutic and adverse effects. To help patients make informed decisions about opioid use, the clinicians prescribing these medications must be able to explain when opioids are likely to help and when they are likely to do harm. Subclasses of opioids include phenanthrenes, benzomorphans, phenylpiperidines, and diphenylheptanes; examples are given of each, with respective utilities and limitations. A discussion then follows of pharmacodynamics, pharmacokinetics, opioid receptor affinity, metabolism, and drug interactions. Tables and figures amplifying the text include: opioid class by synthetic method (Table 8.1); common physiological effects by opioid receptor subtypes (Table 8.2); opioid activity (Table 8.3); and a listing of figures and tables located in Appendix B (opioid receptor affinity, respiratory depression with opioids, adverse effects, metabolism, pharmacogenetics, extended release/long-acting opioids, abuse deterrent formulations). A text box provides supplemental resources.

1995 ◽  
Vol 144 (3) ◽  
pp. 503-510 ◽  
Author(s):  
S Kapas ◽  
A Purbrick ◽  
J P Hinson

Abstract While there have been several studies on the actions of opioid peptides on adrenocortical steroidogenesis, the results of these studies have failed to resolve the question as to whether these peptides exert a direct action on the adrenal cortex. The present studies were designed to address this question directly, using collagenase-dispersed rat zona glomerulosa and zonae fasciculata/reticularis cells incubated in vitro. The results obtained clearly show that the opioid peptides tested (β-endorphin, Leu-enkephalin, Met-enkephalin, and its long-acting analogue, DALA) all exerted a significant stimulatory effect on aldosterone secretion by zona glomerulosa cells and all, except Leuenkephalin, stimulated corticosterone secretion by inner zone cells. The response was shown to be inhibited by naloxone. There did not appear to be a significant interaction between the effects of ACTH and the opioid peptides on adrenocortical cells. Studies using specific agonists for opioid receptor subtypes (DAMGO, DPDPE and U-50488H, specific for μ, δ and κ receptors respectively) showed that the effect of opioid peptides on the zona glomerulosa appeared to be mediated exclusively by μ receptors while the response of inner zone cells was mediated by both μ and, to a lesser extent, κ receptors. Finally, studies on the second messenger systems activated by the opioid peptides and the receptor agonists showed that these peptides act to increase labelling of inositol trisphosphate, and strongly suggest that, in the rat adrenal cortex, both μ and κ opioid receptors are linked to the activation of phospholipase C. Journal of Endocrinology (1995) 144, 503–510


1997 ◽  
Vol 273 (3) ◽  
pp. R956-R959 ◽  
Author(s):  
M. Bertolucci ◽  
C. Perego ◽  
M. G. De Simoni

The central endogenous opioid system is involved in the modulation of interleukin (IL)-6, an inflammatory cytokine that plays a major role in the acute phase response. The present study evaluates whether specific opioid receptor subtypes are selectively involved in this immunomodulatory action. IL-1 beta was administered either intracerebroventricularly or intraperitoneally at the dose of 400 ng to rats pretreated with the mu-antagonist beta-funaltrexamine, the delta-antagonist naltrindole, or the kappa-antagonist nor-binaltorphimine, each at the doses of 1, 10, and 100 micrograms/rat intracerebroventricularly. Serum IL-6 levels were measured 2 h later. The results show that mu-receptor blockade increases, whereas delta-receptor blockade decreases IL-6 induction, suggesting that the fine tuning exerted by opioids on the immune system may be achieved through a balance of opposing effects. Moreover the three antagonists affect IL-6 induction by central and peripheral IL-1 beta with a similar pattern, indicating that the brain endogenous opioid system plays a general role in the regulation of this cytokine.


Appetite ◽  
1991 ◽  
Vol 17 (3) ◽  
pp. 239 ◽  
Author(s):  
Richard J. Bodnar ◽  
Nori Geary

2003 ◽  
Author(s):  
Michael Ossipov ◽  
Josephine Lai ◽  
Todd Vanderah ◽  
Frank Porreca

2009 ◽  
Vol 30 (4) ◽  
pp. 671-678 ◽  
Author(s):  
Peter W. Marinelli ◽  
Douglas Funk ◽  
Stephen Harding ◽  
Zhaoxia Li ◽  
Walter Juzytsch ◽  
...  

1994 ◽  
Vol 264 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Rainer Spanagel ◽  
Osborne F.X. Almeida ◽  
Toni S. Shippenberg

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