Robert M, Jouanjus E, Khouri C, Fouilhe Sam-Lai N, Revol B. The opioid epidemic: A worldwide exploratory study using the WHO pharmacovigilance database. Addiction. 2023;118(4):771–5.

Article  PubMed  Google Scholar 

Palau CB, Akikuni M, Latsky-Campbell B, Wagner J. The Drug Overdose Epidemic in the U.S.-Mexico Border Region: Shifts, Progression, and Community Characteristics. Subst Use Misuse. 2024;59(2):184–92.

Article  PubMed  Google Scholar 

Ciccarone D. The rise of illicit fentanyls, stimulants and the fourth wave of the opioid overdose crisis. Curr Opin Psychiatry. 2021;34(4):344–50.

Article  PubMed  PubMed Central  Google Scholar 

Infante AF, Elmes AT, Gimbar RP, Messmer SE, Neeb C, Jarrett JB. Stronger, longer, better opioid antagonists? Nalmefene is NOT a naloxone replacement. Int J Drug Policy. 2024;124:104323.

Article  PubMed  Google Scholar 

Delaney SR, Konforte D, Stefan C, et al. Drug checking services as a surveillance tool for clinical laboratories: Examining trends in the unregulated fentanyl supply. Clin Biochem. 2023;111:11–6.

Article  PubMed  Google Scholar 

Kelly E, Sutcliffe K, Cavallo D, Ramos-Gonzalez N, Alhosan N, Henderson G. The anomalous pharmacology of fentanyl. Br J Pharmacol. 2023;180(7):797–812.

Article  CAS  PubMed  Google Scholar 

Cook RR, Foot C, Arah OA, et al. Estimating the impact of stimulant use on initiation of buprenorphine and extended-release naltrexone in two clinical trials and real-world populations. Addict Sci Clin Pract. 2023;18(1):11.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Orndorff M, Shipp GM, Kerver JM, Ondersma SJ, Alshaarawy O. Trends in cocaine use among United States females of reproductive age, 2005–2019. Am J Addict. 2024;33(3):313–9.

Article  PubMed  Google Scholar 

Liu X, Singer ME. Intentional use of both opioids and cocaine in the United States. Prev Med Rep. 2023;33:102227.

Article  PubMed  PubMed Central  Google Scholar 

Friedman J, Shover CL. Charting the fourth wave: Geographic, temporal, race/ethnicity and demographic trends in polysubstance fentanyl overdose deaths in the United States, 2010–2021. Addiction. 2023;118(12):2477–85.

Article  PubMed  Google Scholar 

Friedman J, Godvin M, Molina C, et al. Fentanyl, heroin, and methamphetamine-based counterfeit pills sold at tourist-oriented pharmacies in Mexico: An ethnographic and drug checking study. Drug Alcohol Depend. 2023;249:110819.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Ikeda K, Kawakami K, Onimaru H, et al. The respiratory control mechanisms in the brainstem and spinal cord: integrative views of the neuroanatomy and neurophysiology. J Physiol Sci. 2017;67(1):45–62.

Article  PubMed  Google Scholar 

Webster LR, Karan S. The Physiology and Maintenance of Respiration: A Narrative Review. Pain Ther. 2020;9(2):467–86.

Article  PubMed  PubMed Central  Google Scholar 

Jonkman AH, de Vries HJ, Heunks LMA. Physiology of the Respiratory Drive in ICU Patients: Implications for Diagnosis and Treatment. Crit Care. 2020;24(1):104.

Article  PubMed  PubMed Central  Google Scholar 

Ritter B, Zhang W. Early postnatal maturation of GABAA-mediated inhibition in the brainstem respiratory rhythm-generating network of the mouse. Eur J Neurosci. 2000;12(8):2975–84.

Article  CAS  PubMed  Google Scholar 

Sun X, Thorn Perez C, Halemani DN, et al. Opioids modulate an emergent rhythmogenic process to depress breathing. Elife. 2019;8.

Kam K, Worrell JW, Ventalon C, Emiliani V, Feldman JL. Emergence of population bursts from simultaneous activation of small subsets of preBotzinger complex inspiratory neurons. J Neurosci. 2013;33(8):3332–8.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Damasceno RS, Takakura AC, Moreira TS. Regulation of the chemosensory control of breathing by Kolliker-Fuse neurons. Am J Physiol Regul Integr Comp Physiol. 2014;307(1):R57-67.

Article  CAS  PubMed  Google Scholar 

Levitt ES, Abdala AP, Paton JF, Bissonnette JM, Williams JT. mu opioid receptor activation hyperpolarizes respiratory-controlling Kolliker-Fuse neurons and suppresses post-inspiratory drive. J Physiol. 2015;593(19):4453–69.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Dhingra RR, Furuya WI, Bautista TG, Dick TE, Galan RF, Dutschmann M. Increasing Local Excitability of Brainstem Respiratory Nuclei Reveals a Distributed Network Underlying Respiratory Motor Pattern Formation. Front Physiol. 2019;10:887.

Article  PubMed  PubMed Central  Google Scholar 

Bateman JT, Levitt ES. Opioid suppression of an excitatory pontomedullary respiratory circuit by convergent mechanisms. Elife. 2023;12.

Kaur S, Pedersen NP, Yokota S, et al. Glutamatergic signaling from the parabrachial nucleus plays a critical role in hypercapnic arousal. J Neurosci. 2013;33(18):7627–40.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Martelli D, Stanic D, Dutschmann M. The emerging role of the parabrachial complex in the generation of wakefulness drive and its implication for respiratory control. Respir Physiol Neurobiol. 2013;188(3):318–23.

Article  PubMed  Google Scholar 

Lynch N, Lima JD, Spinieli RL, Kaur S. Opioids, sleep, analgesia and respiratory depression: Their convergence on Mu (mu)-opioid receptors in the parabrachial area. Front Neurosci. 2023;17:1134842.

Article  PubMed  PubMed Central  Google Scholar 

Dahan A, Sarton E, Teppema L, et al. Anesthetic potency and influence of morphine and sevoflurane on respiration in mu-opioid receptor knockout mice. Anesthesiology. 2001;94(5):824–32.

Article  CAS  PubMed  Google Scholar 

Engstrom L, Engblom D, Ortegren U, Mackerlova L, Paues J, Blomqvist A. Preproenkephalin mRNA expression in rat parabrachial neurons: relation to cells activated by systemic immune challenge. Neurosci Lett. 2001;316(3):165–8.

Article  CAS  PubMed  Google Scholar 

Dutschmann M, Morschel M, Kron M, Herbert H. Development of adaptive behaviour of the respiratory network: implications for the pontine Kolliker-Fuse nucleus. Respir Physiol Neurobiol. 2004;143(2–3):155–65.

Article  PubMed  Google Scholar 

Baldo BA. Current research in pathophysiology of opioid-induced respiratory depression, neonatal opioid withdrawal syndrome, and neonatal antidepressant exposure syndrome. Curr Res Toxicol. 2022;3:100078.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Kirby GC, McQueen DS. Characterization of opioid receptors in the cat carotid body involved in chemosensory depression in vivo. Br J Pharmacol. 1986;88(4):889–98.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Varga AG, Reid BT, Kieffer BL, Levitt ES. Differential impact of two critical respiratory centres in opioid-induced respiratory depression in awake mice. J Physiol. 2020;598(1):189–205.

Article  CAS  PubMed  Google Scholar 

Zhuang J, Gao X, Gao F, Xu F. Mu-opioid receptors in the caudomedial NTS are critical for respiratory responses to stimulation of bronchopulmonary C-fibers and carotid body in conscious rats. Respir Physiol Neurobiol. 2017;235:71–8.

Article  CAS  PubMed  Google Scholar 

Poole SL, Deuchars J, Lewis DI, Deuchars SA. Subdivision-specific responses of neurons in the nucleus of the tractus solitarius to activation of mu-opioid receptors in the rat. J Neurophysiol. 2007;98(5):3060–71.

Article  CAS  PubMed  Google Scholar 

Souza G, Stornetta RL, Stornetta DS, Abbott SBG, Guyenet PG. Contribution of the Retrotrapezoid Nucleus and Carotid Bodies to Hypercapnia- and Hypoxia-induced A