{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T23:43:17Z","timestamp":1784763797500,"version":"3.55.0"},"reference-count":14,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2020,7,27]],"date-time":"2020-07-27T00:00:00Z","timestamp":1595808000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Brain Sciences"],"abstract":"<jats:p>Opioids are the mainstay for the management of moderate to severe pain. However, their acute use is associated with several side effects, ranging from nausea, itching, sedation, hypotension to respiratory depression, and death. Also, chronic use of these drugs can lead to the development of tolerance, dependence, and eventually addiction. The most serious side effect, lethality due to opioid-induced overdose, has reached the level of national emergency, i.e., the opioid crisis, which is now the forefront of medicine. In a detailed review (Novel Synthetic Opioids: The Pathologist\u2019s Point of View), Frisoni and colleagues have discussed the side effects of novel licit and illicit fentanyl derivatives, as well as the related compounds which are more potent and faster acting than morphine and other conventional opioids (Frisoni, et al., 2018). These drugs affect the central nervous system (CNS) and can promote the development of addiction due to the quick rush they induce because of their faster entry into the brain. These drugs also arrest the cardiovascular and pulmonary systems, increasing the chance of respiratory arrest, leading to opioid-induced overdose morbidity and mortality. The respiratory arrest induced by opioids can be potentiated by other CNS depressants, such as alcohol or benzodiazepines, and therefore may occur more frequently in polydrug users. Therefore, the use of these newer fentanyl derivatives as well as other fast acting opioids should be avoided or limited to specific cases and must be kept out of the reach of children and adolescents who are more vulnerable to become addicted or overdose themselves.<\/jats:p>","DOI":"10.3390\/brainsci10080485","type":"journal-article","created":{"date-parts":[[2020,7,27]],"date-time":"2020-07-27T09:24:49Z","timestamp":1595841889000},"page":"485","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Opioid Crisis\u2014An Emphasis on Fentanyl Analogs"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0350-3693","authenticated-orcid":false,"given":"Kabirullah","family":"Lutfy","sequence":"first","affiliation":[{"name":"College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,7,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"483","DOI":"10.1523\/JNEUROSCI.12-02-00483.1992","article-title":"Opioids excite dopamine neurons by hyperpolarization of local interneurons","volume":"12","author":"Johnson","year":"1992","journal-title":"J. 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