Pain and opioids

Abstract

Noxious stimuli cause pain to protect the body from harmful situations and attract attention to pathophysiologic changes of the body. Specific receptors of pain (nociceptors) can be found all over our body. Pain initiates protecting mechanisms such as vegetative and motor reflexes, and emotional, behavioral changes. However, chronic pain is practically useless and leads to psychopathological changes. There are several ways to relieve pain including non-steroid anti-inflammatory agents, opioids, neurosurgical and non-invasive methods. Central and peripheral effects of opioids can be realized through opioid receptors of the central and the enteric nervous system. In the central nervous system, they can inhibit the perception of pain or change the emotional reactions. Opioids are indicated in postoperative pain, neuropathic pain and cancer. However, the use of opioids has severe side-effects such as breathing depression and the development of tolerance and dependence which do not make opioids optimal painkillers. There are several laboratories in Hungary and abroad working on the design of optimal pain relievers. Furthermore, the euphoric effects of opioids lead to abuse which makes the research important on the mechanisms of opioid addiction. Taken together, opioid research, the design of new compounds and the exploration of the mechanisms of opiate addiction are very important.

Efficacy-Based Perspective to Overcome Reduced Opioid Analgesia of Advanced Painful Diabetic Neuropathy in Rats

“…MOR number apparently was low at the level of DRG and spinal dorsal horn, in accordance with previous data that showed a significant decrease in MOR in the spinal cord of animals with diabetic neuropathy (Shaqura et al, 2013). Therefore, the supraspinal region is largely responsible for morphine analgesia supported by G-coupling in the present work and other in vivo studies (Muranyi and Radak, 2008; Al-Khrasani et al, 2012). In addition, advance in diabetes (12 weeks) could also affect the effect of fentanyl on G-protein activation, though in contrast to morphine it still produces significant effect in term of efficacy ( E max ).…”

Zinc enhances the expression of morphine-induced conditioned place preference through dopaminergic and serotonergic systems

“…Endogenous opioids and opioid analgesics, i.e. morphine, have been of interest because they have analgesic and psychologically reinforcing effects which can involve in abuse [1]. Some researchers reported that morphine has positive reinforcement through activation of µ receptor which facilitates dopamine (DA) release [2][3][4].…”

“…The literature contains many examples of self-dual Leonard pairs. ated with an irreducible module for the Terwilliger algebra of the hype Leonard pair of Krawtchouk type (see [10, De nition 6.1]); (iii) the Leo module for the Terwilliger algebra of a distance-regular graph that ha bra (see [1,Theorem], [3,Theorems 4.1, 5.5]); (iv) an appropriately no (see [11,Lemma 14.8]); (v) the Leonard pair consisting of any two of a De nition 1.4]); (vi) the Leonard pair consisting of a pair of opposite bra, acting on an evaluation module (see [5,Proposition 9.2]). The exa examples (iii), (iv) are special cases of (v).…”

Effect of housing in an enriched environment on the recovery from experimental inflammatory pain

“…Opioids are the most commonly used analgesics for treatment of moderate-tosevere postoperative pain [42,43] and are widely used in patient-controlled analgesia systems [41,44]. However, the use of opioids can induce severe side-effects such as breathing depression and the development of tolerance and dependence [45]. Therefore, for the management of less severe postoperative pain, drugs such as paracetamol or non steroid anti-inflammatory drugs (NSAID's) are preferred.…”