ABSTRACT
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.
Subject(s)
Antiemetics/therapeutic use , Nausea/drug therapy , Vomiting/drug therapy , Adult , Central Nervous System Diseases/complications , Child , Cholinergic Antagonists/therapeutic use , Dopamine Antagonists/therapeutic use , Female , Histamine H1 Antagonists/therapeutic use , Humans , Intestinal Diseases/complications , Male , Nausea/etiology , Postoperative Nausea and Vomiting/drug therapy , Pregnancy , Pregnancy Complications/drug therapy , Serotonin Antagonists/therapeutic use , Vomiting/etiologyABSTRACT
Ingestion of ethylene glycol may be an important contributor in patients with metabolic acidosis of unknown cause and subsequent renal failure. Expeditious diagnosis and treatment will limit metabolic toxicity and decrease morbidity and mortality. Ethylene glycol poisoning should be suspected in an intoxicated patient with anion gap acidosis, hypocalcemia, urinary crystals, and nontoxic blood alcohol concentration. Fomepizole is a newer agent with a specific indication for the treatment of ethylene glycol poisoning. Metabolic acidosis is resolved within three hours of initiating therapy. Initiation of fomepizole therapy before the serum creatinine concentration rises can minimize renal impairment. Compared with traditional ethanol treatment, advantages of fomepizole include lack of depression of the central nervous system and hypoglycemia, and easier maintenance of effective plasma levels.
