Opioids for persistent noncancer pain

Twenty-three medication-taking traits and stroke: A comprehensive Mendelian randomization study

Background

Certain medication categories may increase the risk of stroke. Nonetheless, the evidence regarding the causal relationship of medication-taking in promoting stroke and subtypes is deficient.

Methods

We evaluated the causal effect of a genetic predisposition for certain medication categories on stroke and subtypes (ischemic and hemorrhagic categories) by a two-sample Mendelian randomization (MR) analysis. Data for 23 medication categories were gathered from a genome-wide association study (GWAS) involving 318,177 patients. The Medical Research Council Integrative Epidemiology Unit Open GWAS database and the FinnGen consortium were used to gather GWAS data for stroke and subtypes. Inverse variance weighted, MR-Egger, and weighted median were used for the estimation of causal effects. Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis were used for sensitivity analyses.

Results

Ten medication categories were linked to a high stroke risk. Nine categories were linked to a high-risk ischemic stroke. Five categories were associated with small vessel ischemic stroke. Nine categories were positively associated with large artery atherosclerotic ischemic stroke. Three categories causally increased the possibility of cardioembolic ischemic stroke. Four categories were associated with intracerebral hemorrhage. Four categories were associated with nontraumatic intracranial hemorrhage. Three categories were causally associated with subarachnoid hemorrhage (SAH). Four categories were associated with the combination of SAH, unruptured cerebral aneurysm, and aneurysm operations SAH.

Conclusions

This study confirms that some medication categories lead to a greater risk of strokes. Meanwhile, it has an implication for stroke screening as well as direct clinical significance in the design of conduction of future randomized controlled trials.

Pain Management Associated with Total Joint Arthroplasty: A Primer

This primer presents a synopsis of pain management strategies associated with total joint arthroplasty. Patients considering total joint arthroplasty often experience moderate to severe pain, which places them at risk of opioid abuse or addiction. Currently, the best practice strategies involve the development of individualized multimodal perioperative approaches to pain management. These practices include prescribing opioids at their lowest dose and for the shortest duration necessary to control symptoms, with close monitoring of common adverse effects. Implementing these practices is essential to battling the ongoing opioid crisis in the US.

N-Pyrazoloyl and N-thiopheneacetyl hydrazone of isatin exhibited potent anti-inflammatory and anti-nociceptive properties through suppression of NF-κB, MAPK and oxidative stress signaling in animal models of inflammation

BACKGROUND

Hydrazide derivatives constitute an important class of compounds for new drug development as they are reported to possess good anti-inflammatory and analgesic activity. The present study was aimed to investigate the role of newly synthesized hydrazide derivatives N-pyrazoloyl hydrazone of isatin (PHI) and N-thiopheneacetyl hydrazone of isatin (THI) in acute and chronic inflammatory pain models induced by carrageenan and complete Freud's adjuvant (CFA).

MATERIALS

PHI and THI (0.1, 1 and 10 mg/kg) pretreatments were provided intraperitoneally to male BALB/c mice prior to inflammatory inducers. Behavioral responses to inflammation and pain were evaluated by assessment of paw edema, mechanical allodynia, mechanical and thermal hyperalgesia. Cytokines production and NF-κB levels were evaluated by ELISA. Western blot analysis was performed for the detection of IκBα, p38, JNK and ERK. Hematoxylin and eosin (H&E) staining and radiographic analysis were performed to evaluate the effect of PHI and THI treatment on bone and soft tissues. Oxidative stress was determined by reduced glutathione, glutathione-S-transferase and catalase assays. Evans blue dye was used to monitor vascular protein leakage.

RESULT

PHI and THI dose dependently (0.1, 1 and 10 mg/kg) reduced inflammation and pain in mice, however, the dose of 10 mg/kg exhibited significant activity. The anti-inflammatory and analgesic effects were attributed to suppression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) production levels. PHI and THI significantly blocked CFA-induced activation of NF-κB and MAPK signaling pathways. Oxidative stress and plasma nitrite levels were reduced remarkably. The PHI and THI (10 mg/kg) treatment did not exhibit any apparent toxicity on the liver, kidney, muscles strength, and motor co-ordination in mice.

CONCLUSION

Both PHI and THI possess significant anti-inflammatory and analgesic activity via inhibition of inflammatory mediators.

Opioid detection in maternal and neonatal hair and meconium: characterization of an at-risk population and implications to fetal toxicology

Identification of maternal opioid abuse in pregnancy is often difficult to ascertain in the absence of a reliable self-report. We aimed to characterize an at-risk neonatal population for opioid exposures as well as other drugs of abuse and alcohol. From June 2007 to January 2009, 563 neonatal hair and 1318 meconium specimens were assessed for opioids and were positive in 11.4% and 17.0%, respectively. Neonates testing positive for opioids in hair or meconium analysis were also more likely to test positive for other licit and illicit substances (odds ratiohair, 1.75; 95% confidence interval, 1.03-2.97; odds ratiomeconium, 1.61; 95% confidence interval, 1.16-2.22). Specifically, a positive neonatal hair test for opioids also predicted a positive result for oxycodone. In addition, a positive meconium test result for opioids was associated with positive results for cocaine, oxycodone, methadone, benzodiazepines, and fatty acid ethyl esters (alcohol). Finally, there was a significant correlation between maternal and neonatal hair test results for opioids (Spearman rank rho = 0.657, P = 0.03). Understanding the addiction profiles of these women may lead to better clinical and social management and may largely benefit an at-risk population.

Shared mechanisms for opioid tolerance and a transition to chronic pain

Clinical pain conditions may remain responsive to opiate analgesics for extended periods, but such persistent acute pain can undergo a transition to an opiate-resistant chronic pain state that becomes a much more serious clinical problem. To test the hypothesis that cellular mechanisms of chronic pain in the primary afferent also contribute to the development of opiate resistance, we used a recently developed model of the transition of from acute to chronic pain, hyperalgesic priming. Repeated intradermal administration of the potent and highly selective mu-opioid agonist, [d-Ala(2),N-MePhe(4),gly-ol]-enkephalin (DAMGO), to produce tolerance for its inhibition of prostaglandin E(2) hyperalgesia, simultaneously produced hyperalgesic priming. Conversely, injection of an inflammogen, carrageenan, used to produce priming produced DAMGO tolerance. Both effects were prevented by inhibition of protein kinase Cepsilon (PKCepsilon). Carrageenan also induced opioid dependence, manifest as mu-opioid receptor antagonist (d-Phe-Cys-Tyr-d-Trp-Orn-Thr-Pen-Thr-NH(2))-induced hyperalgesia that, like priming, was PKCepsilon and G(i) dependent. These findings suggest that the transition from acute to chronic pain, and development of mu-opioid receptor tolerance and dependence may be linked by common cellular mechanisms in the primary afferent.