Cancer Pain
Gary W. Jay in Practical Guide to Chronic Pain Syndromes, 2016
Side effects of opioids are generally preventable or easily managed in most individuals with cancer (19). Nausea can occur when patients are first exposed to an opioid; providing an around-the-clock antiemetic for the first 24 to 48 hours in patients who have experienced this adverse effect of opioids in the past can manage this effect. Since many people with cancer have already been treated with an antiemetic during chemotherapy administration, select an antiemetic that has been well tolerated by the patient in the past, such as phenothiazines, including prochlorperazine, or prokinetic agents such as metoclopramide. In more refractory cases, haloperidol or dexamethasone may be effective. Serotonin 5-HT3 receptor antagonists likely have limited utility in the management of prolonged opioid-induced nausea and vomiting. Other potential causes of nausea, such as malignant bowel obstruction, concomitant medications, or increased pressure from intracranial metastases, should be ruled out.
Neuropharmacology Of Respiration
Alan D. Miller, Armand L. Bianchi, Beverly P. Bishop in Neural Control of the Respiratory Muscles, 2019
Most 5-HT cell clusters are located in the raphe nuclei in the medial part of the brainstem. There are several subtypes of 5-HT receptors; 5-HT1, 5-HT2, and 5-HT3 receptors were identified in the nucleus tractus solitarius (NTS), in vagal afferent terminals, and in the area postrema. 5-HT afferents alone or associated with other neurotransmitters project to brainstem respiratory areas. Of particular interest is the localization of 5-HT boutons on presumed respiratory neurons of the DRG. Sometimes, varicosities of functionally unidentified neurons from the NTS contain both 5-HT and substance R The colocalization of 5-HT and substance P is important since functional interactions have been demonstrated in the NTS.41
Development of palliative medicine in the United Kingdom and Ireland
Eduardo Bruera, Irene Higginson, Charles F von Gunten, Tatsuya Morita in Textbook of Palliative Medicine and Supportive Care, 2015
Many factors should be considered when choosing antiemetic treatment. History, examination, and review of the ongoing drug regimen are generally helpful in finding the cause of gastrointestinal symptoms in the neurological population. A multitude of medications, including opioids, digoxin, antibiotics, imidazoles, and cytotoxics, can cause nausea and vomiting by acting on the CTZ, whereas NSAIDs, iron supplements, antibiotics, and tranexamic acid may damage gastric mucosa. Opioids, tricyclics, phenothiazines, and anticholinergics induce gastric stasis. Finally, selective serotonin reuptake inhibitors and cytotoxic drugs may induce 5-HT3 receptor stimulation. Uncontrolled pain per se may be a cause of nausea and vomiting.
Role of serotonin hormone in weight regain after sleeve gastrectomy
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2018
Hala M. Demerdash, Ahmed A. Sabry, Emad A. Arida
In the present study, the increased serotonin concentration in group II (two years post-operatively) compared to both the pre-operative level and to the one-year post-operative level may be due to luminal stimulation of the GIT due to increased disaccharides. Alternatively, it may be due to increased intra-luminal pressure because of fermentation and improper food digestion as a consequence of the surgical procedure and the type of food consumed (carbohydrates) [25]. These factors induce serotonin release, which in turn activates 5-HT3 receptors on mucosal vagal afferent terminals. Serotonin acts as a paracrine substance to stimulate pancreatic secretion via a vagal cholinergic pathway [25]. Pancreatic β-cells receptors contain intracellular serotonin combined with two activated GTPases (Rab3a and Rab27a) and trigger insulin release by the exocytosis of β-granules. Extracellular serotonin acts on 5-HT1A receptors on the membrane of β-cells to inhibit insulin secretion through the effects on cAMP. Thus, insulin secretion from pancreatic β-cells is determined by the concentration difference between intra- and extra-cellular serotonin levels [26]. This may provide an explanation for the decreased insulin level in group II compared to group I and to the results obtained one-year post-operative. The role of serotonin may indicate an additional level of complexity in the interplay of the above mentioned signaling molecules in weight control regulation [25].
Gastroparesis syndromes: emerging drug targets and potential therapeutic opportunities
Published in Expert Opinion on Investigational Drugs, 2023
Le Yu Naing, Matthew Heckroth, Prateek Mathur, Thomas L Abell
5-HT3 receptors differ from all other 5-HT receptors in that they are ligand-gated ion channels, whereas the others are G-protein linked receptors. Activation of 5-HT3 receptors inhibits gastric secretions, stimulates migrating motor complexes, and increases intestinal secretions, accelerating small bowel transit. They also stimulate gastric antral contractions and vagal afferent nerves initiating the vomiting reflex[31]. 5-HT3 receptor antagonists are potent antiemetics often used to treat the symptoms of Gp. They block serotonin both peripherally on vagal nerve terminals in the GI tract, as well as centrally in the area postrema and nucleus tractus solitarius. Available 5-HT3 receptor antagonists include ondansetron (Zofran), granisetron (Kytril), tropisetron (Navoban), dolasetron (Anzamet), ramosetron (Nasea), and palonosetron (Aloxi). Some of them have been associated with QT prolongation on EKG, and it is recommended that patients with congenital long QT syndrome need to be cautious with their use. For patients with significant electrolyte abnormalities, congestive heart failure, or those taking other medications that prolong the QT interval, monitoring with serial EKGs is recommended.
Ondansetron versus ondansetron with dexamethasone to prevent intrathecal-morphine pruritus for caesarean patients: randomised double-blind trial
Published in Journal of Obstetrics and Gynaecology, 2021
Thaer Ankouni, Saleh Kanawati, Rania El Khatib, Janah El Hassan, Saad Eddine Itani, Omar Rajab, Zoher Naja
The use of neuraxial opioids in the obstetric population provides effective long-lasting postoperative analgesia but have adverse side effects that include nausea, vomiting, and pruritus (Charuluxananan et al. 2000; Siddik-Sayyed et al. 2007; Yurashevich and Habib 2019). The incidence of pruritus in caesarean section patients has been reported to be between 36% and 60% (Weigl et al. 2017; Thay et al. 2018). The exact mechanism of opioid-induced pruritus is unclear but it could be due to an interaction between oestrogen, opioid receptors and central serotonin receptors (Waxler et al. 2005; Bonnet et al. 2008). It has been suggested that the interaction between opioids and 5-hydroxytryptamine subtype 3 (5HT3) receptors could have a role in causing neuraxial opioid-induced pruritus. 5-HT3 receptors are numerous in the spinal tract of the trigeminal nerve in the medulla and in the dorsal horn of the spinal cord. Therefore, 5-HT3 antagonists such as ondansetron have been identified as possible antipruritic agents (Koju et al. 2015; Kumar and Singh 2013).
Related Knowledge Centers
- Central Nervous System
- Nervous System
- Peripheral Nervous System
- Sodium
- Serotonin
- Cys-Loop Receptor
- Ligand-Gated Ion Channel
- 5-Ht Receptor
- G Protein-Coupled Receptor
- Ion