ABSTRACT
Nausea and vomiting are mediated primarily by three neurotransmitter pathways: visceral stimulation releases dopamine and serotonin; vestibular and central nervous system activation release histamine and acetylcholine; and chemoreceptor trigger zone activation releases dopamine and serotonin. Clinicians can improve the effectiveness and cost-effectiveness of treatments by targeting the appropriate pathways. Antihistamines and anticholinergics are most effective in patients with vestibular-mediated nausea secondary to vertigo. Serotonin antagonists block serotonin in the intestines and chemoreceptor trigger zone, and are most effective for treating gastroenteritis. Dopamine antagonists block dopamine in the intestines and chemoreceptor trigger zone; indications for these agents are similar to those for serotonin antagonists. For treatment of mild pregnancy-induced nausea, pyridoxine with or without doxylamine is recommended, and ginger may also be effective. In patients with migraine headache-associated nausea, metoclopramide improves response to oral anti-migraine agents. Ondansetron reduces nausea and vomiting in children with acute gastroenteritis and in women with hyperemesis gravidarum.
Subject(s)
Antiemetics/therapeutic use , Clinical Decision-Making/methods , Nausea/drug therapy , Nausea/etiology , Vomiting/drug therapy , Vomiting/etiology , Antiemetics/standards , Female , Gastritis/complications , Gastritis/drug therapy , Humans , Hyperemesis Gravidarum/drug therapy , Migraine Disorders/complications , Migraine Disorders/drug therapy , Pregnancy , Vertigo/complications , Vertigo/drug therapy , Vestibular Diseases/complications , Vestibular Diseases/drug therapySubject(s)
DEET/therapeutic use , Insect Bites and Stings/prevention & control , Insect Repellents/therapeutic use , Administration, Topical , Age Factors , Animals , Child , Child, Preschool , DEET/adverse effects , Dose-Response Relationship, Drug , Drug Administration Schedule , Evidence-Based Medicine , Family Practice/methods , Female , Humans , Male , Risk Assessment , Sensitivity and SpecificityABSTRACT
An understanding of the pathophysiology of nausea and the mechanisms of antiemetics can help family physicians improve the cost-effectiveness and efficacy of therapy. Nausea and vomiting are mediated primarily by visceral stimulation through dopamine and serotonin, by vestibular and central nervous system causes through histamine and acetylcholine, and by chemoreceptor trigger zone stimulation through dopamine and serotonin. Treatment is directed at these pathways. Antihistamines and anticholinergic agents are most effective in patients with nausea resulting from vestibular and central nervous system causes. Dopamine antagonists block dopamine in the intestines and chemoreceptor trigger zone; indications for these agents are similar to those for serotonin antagonists. Serotonin antagonists block serotonin in the intestines and chemoreceptor trigger zone, and are most effective for treating gastrointestinal irritation and postoperative nausea and vomiting. Complementary and alternative therapies, such as ginger, acupressure, and vitamin B6, have variable effectiveness in the treatment of pregnancy-induced nausea.
