Newest Drugs for Chronic Unexplained Nausea and Vomiting.

OPINION STATEMENT: Chronic unexplained nausea and vomiting (CUNV) refers to a symptom complex defined by nausea and/or vomiting with normal diagnostic testing, including anatomic assessments (including upper endoscopy) and measures of upper gut function (e.g., gastric emptying testing). Nausea and vomiting in this condition are postulated to result from aberrant peripheral or central neurohumoral activity. A substantial subset of patients satisfies this diagnosis as more than half of individuals referred for scintigraphic testing exhibit normal gastric emptying rates. No randomized, placebo-controlled trials of any medication treatment have been performed in CUNV. However, agents with potential therapeutic benefits in CUNV include antiemetic drugs, neuromodulatory treatments which are proposed to act by reducing gastric sensitivity, and medications with prokinetic action to stimulate upper gut propulsion. Recently approved drugs with antiemetic capability include serotonin antagonists with novel modes of delivery and neurokinin antagonists with or without additional serotonergic blocking capabilities. Existing neuroleptics and pain-modifying neuromodulatory therapies with fortuitous antiemetic benefits are being considered for their benefits in this disorder. Furthermore, current investigations will define potential therapeutic actions of agents that stimulate gastric emptying via action on gastroduodenal serotonin, motilin, and ghrelin receptors. This current research may broaden the treatment options for refractory cases of unexplained nausea and vomiting.