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Induction of Anesthesia
Published in Michele Barletta, Jane Quandt, Rachel Reed, Equine Anesthesia and Pain Management, 2023
Kristen Messenger, Rachel Reed
Ketamine: The most commonly used drug for the induction of anesthesia in horses. It is a phencyclidine derivative, and its mechanism of action is via antagonism of the N-methyl-D-aspartate (NMDA) receptor. Ketamine provides smooth induction of anesthesia with a large margin of safety.It is a sympathomimetic drug, so induction of anesthesia is associated with an increase in heart rate and cardiac output in patients that have an intact sympathetic nervous system at the time of induction.Furthermore, it is long lasting, with a single induction dose providing 15–20 minutes of recumbency time.Ketamine also has analgesic effects via NMDA receptor antagonism and opioid receptor agonism.Additionally, the drug is cost-effective and capable of inducing general anesthesia in a horse with reasonable volumes.Ketamine does not provide good muscle relaxation; therefore, it is often combined with a benzodiazepine in a co-induction protocol.
The Effect of Anti-Asthmatic Drugs on Airway Hyperresponsiveness and Inflammation
Published in Devendra K. Agrawal, Robert G. Townley, Inflammatory Cells and Mediators in Bronchial Asthma, 2020
The acute administration of inhaled sympathomimetics causes a consistent decrease in airway responsiveness to histamine or methacholine.39 The effect is dose related, and the duration of the protective effect is dependent on the type of sympathomimetic drug. Longterm administration of inhaled sympathomimetics does not really modify the airway responsiveness to histamine or methacholine, except for a temporary rebound increase in responsiveness after the acute reduction.40 The acute administration of inhaled anticholinergics has very little effect on airway responsiveness.39 A transient increase in reactivity to methacholine was observed after prolonged treatment with inhaled ipratropium.41
Peripheral Autonomic Neuropathies
Published in David Robertson, Italo Biaggioni, Disorders of the Autonomic Nervous System, 2019
Simple external supports to reduce the volume for blood pooling in the legs and abdomen are useful, but because they are cumbersome they are not usually accepted for long. Pressor drugs, which cause improvement in postural hypotension, include phenylephrine, which has a direct sympathomimetic action and, less effectively, ephedrine, an indirect sympathomimetic drug. These drugs have a tendency to aggravate recumbent hypertension. Midodrine (Schirger et al., 1981) has been used. The constrictor effects of this drug are attributed to its alpha-agonist activity on both arterioles and veins.
A cluster of 25B-NBOH poisonings following exposure to powder sold as lysergic acid diethylamide (LSD)
Published in Clinical Toxicology, 2022
Sean T. Ivory, Joe-Anthony Rotella, Jennifer Schumann, Shaun L. Greene
Both presentations of confirmed 25B-NBOH toxicity presented with signs consistent with sympathomimetic toxicity, including tachycardia, hypertension, agitation, and seizures. The clinical features observed are similar to those reported following 25I-NBOMe exposure, namely tachycardia, hypertension, hyperglycaemia, agitation, hallucinations, and status epilepticus [4]. Rhabdomyolysis and associated AKI are reported complications of sympathomimetic drug exposure producing severe agitation or prolonged seizures with excessive muscular activity. While symptoms, such as tachycardia, hypertension, and hallucinations are also commonly associated with LSD use [15], seizures and rhabdomyolysis are very rarely reported. Hyperthermia was not observed in our cases but is recognised as a potentially life-threatening complication observed with some serotonergic drugs including 3,4-methylenedioxymethamphetamine (MDMA) [16]. Although 25B-NBOH and MDMA are both 5HT2A receptor agonists, evidence suggests that other receptors, including alpha-2, play a role in MDMA hyperthermia [16]. The effects of 25B-NBOH on other receptors have not been described.
A novel approach to treatment of priapism refractory to non-surgical methods: A single-case experience
Published in Arab Journal of Urology, 2019
Nassib Abou Heidar, Jad A. Degheili, Gerges Bustros, Wassim Wazzan, Muhammad Bulbul
To the authors’ best knowledge, continuous irrigation with a sympathomimetic drug has not been reported in the literature before, and has shown to be successful in our present case. The authors understand the reluctance of physicians to administer continuous α-adrenergic drug due to the risk of necrosis; however, our dosage was the same as that reported in the literature. Continuous irrigation could at the molecular level saturate the α-adrenergic receptors rendering it more effective. Conceptually, there is an increased risk of systemic absorption of the sympathomimetic drug, which can cause tachyarrhythmias and elevated blood pressure, which were accounted for by continuous telemetry and vital signs monitoring [9]. Another risk of continuous infusion is regional penile ischaemia and local infection, which did not occur in this particular case, but were monitored for and did not happen. The authors used phenylephrine since AUA and European Association of Urology (EAU) guidelines propose phenylephrine as the first drug of choice for intermittent injections [3,4], whilst other agents could similarly be efficacious but they were not tried.
Is pharmacotherapy enough for urgent weight loss in severely obese patients?
Published in Expert Opinion on Pharmacotherapy, 2019
Javier Gargallo-Vaamonde, Carolina M. Perdomo, Magdalena de la Higuera, Gema Frühbeck, Javier Salvador
In the last years, new antiobesity medications (AOMs) have been marketed for obesity therapy. The combinations of phentermine-topiramate and naltrexone-bupropion, the GLP-1 receptor agonist (GLP-1 RA) liraglutide and lorcaserin, a serotonin receptor-2C agonist, have been approved in the US for obesity treatment, whereas only the naltrexone-bupropion combination and liraglutide have been authorized in the EU [8]. Recently, semaglutide, a powerful GLP-1 RA, has also been launched in different countries for the treatment of type 2 diabetes. All these drugs join orlistat, a well-known intestinal fat absorption blocker, and phentermine, a sympathomimetic drug, in the pharmacological armamentarium available for obesity management [8].