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Substance Use Disorders
Published in Vincenzo Berghella, Maternal-Fetal Evidence Based Guidelines, 2022
Opioids are chemicals that bind to the opioid receptor. The term “opiate” refers to the naturally occurring alkaloids (morphine, codeine, heroin) found in opium. Street names for heroin in the United States include Big H, Black Tar, Chiva, Hell Dust, Horse, Negra, and Smack. Opioids can be taken orally, sniffed, smoked, absorbed through the skin, or injected (most common route of administration for heroin). Heroin may be “cut” with adulterants such as quinine, cornstarch, or powdered baby formula. Heroin's short half-life requires use multiple times per day to avoid withdrawal. The diagnosis of opioid use disorder (OUD) is based on specific criteria defined by the Diagnostic and Statistical Manual of Mental Disorder, Fifth Edition (DSM-5), and is graded as mild (2–3), moderate (4–5), or severe (6 or more) depending on the number of recurring symptoms (Table 23.7).
Neuropeptides: Evidence for Central Pathways and Role in Cardiovascular Regulation
Published in Irving H. Zucker, Joseph P. Gilmore, Reflex Control of the Circulation, 2020
Giora Feuerstein, Anna Leena Siren, Stefan Vonhof, Robert Willette
Concurrently with the proliferation of the number of endogenous opioid peptides found in central and peripheral neural elements (including the adrenal medulla), the number of opioid receptor subtypes also increased steadily (North and Egan, 1983; Khatchaturian et al., 1985; Hedner and Nordberg, 1989). The type and main pharmacological actions of the putative opioid receptors are summarized in Table 1. In brief, these opioid receptors have been implicated in extremely diverse biological actions of which modulation of pain perception has been most extensively studied. However, the opioid system was shown to be involved in food consumption, regulation of body temperature, pituitary hormone release, respiration, behavior, and cardiovascular regulation (Krieger, 1982; Holaday, 1983; Koob and Bloom, 1983; Hedner and Casuto, 1987; Feuerstein, 1987a,b,c, 1988). In the present chapter, the role of the opioid peptides in regulation of cardiovascular functions and particularly the baroreceptor system will be reviewed.
Pharmacotherapy of Neurochemical Imbalances
Published in Sahab Uddin, Rashid Mamunur, Advances in Neuropharmacology, 2020
Rupali Patil, Aman Upaganlawar, Suvarna Ingale
Peptides, which bind to opioid receptors, are called opioid peptides. Opioid peptides are also called opioid neuropeptides or opioid neuromodulators. Opioid receptors are the membrane proteins located in nerve endings in brain and GIT. Opioid receptors are of three types: µ, κ, and δ. These proteins are called opioid receptors because of their affinity toward the opiate or morphine, which are derived from opium. Opiate and morphine act by binding with the receptor proteins (opioid receptors) for the natural neuropeptides. Natural neuropeptides are called endogenous opioid peptides. Endogenous opioid peptides have opiate like activity and inhibit the neurons in the brain involved in pain sensation (Froehlich, 1997). Opioid peptides are of three types:
Advantages and feasibility of intercostal nerve block in uniportal video-assisted thoracoscopic surgery (VATS)
Published in Postgraduate Medicine, 2023
Analgesic drugs commonly used after chest surgery include NSAIDs, opioid analgesics, and acetaminophen. NSAIDs inhibit the synthesis of cyclooxygenase (COX) and prostaglandin (PG). Ketorolac tromethamine is a nonselective COX inhibitor administered intravenously. While it can reduce opioid dosage and related adverse effects such as nausea, vomiting, and excessive sedation, its main side effects include gastrointestinal bleeding and an increased risk of postoperative bleeding. In contrast, acetaminophen inhibits PG synthesis by acting on the central nervous system and has fewer side effects than NSAIDs. Acetaminophen is effective for mild to moderate pain and can enhance the analgesic effects of opioids or NSAIDs when used in combination, but high doses may lead to liver damage [25]. Opioids activate opioid receptors in the peripheral and central nervous systems, producing analgesia. Dezocine, an opioid receptor agonist, has a similar analgesic effect to morphine, but has a ceiling effect on both analgesic and side effects [26]. Dose escalation beyond a certain point does not increase analgesia but may increase the risk of side effects, such as respiratory depression. Combining dezocine with other types of analgesic drugs can have a synergistic effect. Ropivacaine is an amide local anesthetic that can enhance postoperative analgesia when combined with epinephrine. However, accidental injection into the bloodstream may cause immediate acute systemic toxicity. Therefore, caution must be exercised during administration to prevent iatrogenic collateral injury.
The possible role of pedunculopontine tegmental nucleus (PPT) opioid receptors in the cardiovascular responses in normotensive and hemorrhagic hypotensive rats
Published in Clinical and Experimental Hypertension, 2022
Mohammad Naser Shafei, Omid Fakharzadeh Moghaddam, Vida Alikhani, Reza Mohebbati
It has been shown that the PPT has three types of neurons, and opioids by hyperpolarization of these types of neurons contribute to hypotension. In addition to direct projection to the RVLM, the PPT neurons were identified to project to other areas aimed at regulating blood pressure, including the vlPAG area (26). In addition, the projection of opioids from PPT is proposed to be polysynaptic and PPT-PAG-RVLM mediated because of the inhibitory effect of the vlPAG on blood pressure (30). We suggest that opioid receptors are involved in this effect. However, it requires to be further studied in the future. The effect of Ach on BP in the PPT is probably negotiated by muscarinic receptor (31). Muscarinic receptors are critical receptors of the brain cholinergic system, and the cardiovascular effects induced by muscarinic receptors have been demonstrated in numerous experiments (18,31,32). Therefore, muscarinic receptors in the PPT (33) may approve this theory.
Accommodative and convergence anomalies in patients with opioid use disorder
Published in Clinical and Experimental Optometry, 2022
Mohaddeseh Ghobadi, Payam Nabovati, Hassan Hashemi, Ali Talaei, Hamid Reza Fathi, Yeganeh Yekta, Hadi Ostadimoghaddam, Abbasali Yekta, Mehdi Khabazkhoob
Opioids are a broad group of pain-relieving drugs that work by interacting with specific receptors in the central nervous system (CNS) called opioid receptors.1 Opioids can be of synthetic origin or derived naturally from the opium poppy plant. Among the most popular opioids are opium, morphine, codeine, heroin, tramadol, fentanyl, and oxycodone.2 According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), opioid use disorder (OUD) is a problematic pattern of opioid use that results in clinically significant impairment or distress. Indicators of OUD include a strong tendency to use opioids, inability to control or reduce use, continuous use despite its professional and social consequences, use of larger amounts over time, spending significant time to obtain and use opioids, and withdrawal symptoms after stopping or reducing use, such as negative mood, muscle aches, nausea or vomiting, and insomnia.3,4 OUD is associated with a range of serious mental and general health comorbid disorders as well as increased mortality, hence it is one of the major public health concerns.5,6 According to a study in 2018, OUD affects more than 16 million people worldwide, and more than 120,000 deaths worldwide annually are attributed to opioids.7