• Nausea scale [ Time Frame: 60m ] [ Designated as safety issue: No ]
  

• Akathisia scale [ Time Frame: 60m ] [ Designated as safety issue: Yes ]
  

The most effective dose of metoclopramide for treatment of nausea in the ED setting has not been thoroughly investigated. One pilot study among ED patients in Australia found no statistical difference between 10 mg and 0.4 mg/kg; another investigation suggests that the anti-emetic effect of 10 mg of metoclopramide is no more effective than placebo. In contrast, investigations focusing on chemotherapy patients and post-operative patients suggest that higher dosage metoclopramide is more effective in treating nausea and vomiting. This ED study will compare the anti-emetic efficacy of 10 mg and 20 mg metoclopramide by using the visual analog scale.

In addition to evaluation of dose, we will evaluate one of the most common side affects of metoclopramide, akathisia. Akathisia is characterized by a subjective component of restlessness and an objective component in the form of the inability to remain motionless. Anti-cholinergic medications are known to reduce extrapyramidal symptoms such as akathisia when dopamine function is impaired in the basal ganglia. In fact, the use of diphenhydramine has been shown to reduce the incidence of akathisia in patients receiving a different anti-emetic, prochlorperazine. However, no research has focused on the use of anti-cholinergic medications to reduce MIA. This investigation will assess the use of 25 mg of diphenhydramine in preventing MIA in ED patients being treated for nausea/vomiting.