The Montefiore Metoclopramide Study

Metoclopramide is a dopamine antagonist frequently used for the treatment of nausea, vomiting, and migraine headaches in Emergency Departments. However, little research has focused on the optimal dose of metoclopramide for treatment of nausea in the emergency department. We propose a randomized, double-blind, placebo controlled trial to investigate the optimal dose of metoclopramide for treatment of nausea.

The most effective dose of metoclopramide for treatment of nausea in the emergency department setting has not been thoroughly investigated. One pilot study among emergency department patients in Australia found no statistical difference between 10 mg and 0.4 milligrams/kilogram; another investigation suggests that the anti-emetic effect of 10 milligrams 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 emergency department study will compare the anti-emetic efficacy of 10 milligrams and 20 milligrams of 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 metoclopramide induced akathisia. This investigation will assess the use of 25 mg of diphenhydramine in preventing metoclopramide induced akathisia in ED patients being treated for nausea/vomiting.

• Nausea
• Extrapyramidal Symptoms

• Drug: metoclopramide 10 mg
  an anti-emetic medication
• Drug: Diphenhydramine 25 mg
  used for prophylaxis against akathisia
• Drug: Placebo
  placebo
• Drug: Metoclopramide 20 mg
  Metoclopramide 20 mg

• Active Comparator: Metoclopramide 20+diphenhydramine
  Metoclopramide 20 mg + diphenhydramine, delivered intravenously over 15 minutes
  Interventions:

  • Drug: Diphenhydramine 25 mg
  • Drug: Metoclopramide 20 mg
• Active Comparator: Metoclopramide 20+placebo
  Metoclopramide 20 mg + placebo, delivered intravenously over 15 minutes
  Interventions:

  • Drug: Placebo
  • Drug: Metoclopramide 20 mg
• Active Comparator: Metoclopramide 10 + placebo
  Metoclopramide 10mg + placebo, delivered intravenously over 15 minutes
  Interventions:

  • Drug: metoclopramide 10 mg
  • Drug: Placebo
• Active Comparator: Metoclopramide 10+diphenhydramine
  Metoclopramide 10 mg + diphenhydramine 25 mg, delivered intravenously over 15 minutes
  Interventions:

  • Drug: metoclopramide 10 mg
  • Drug: Diphenhydramine 25 mg

Inclusion Criteria:

• primary or secondary complaints of nausea/vomiting
• age 21-65

Exclusion Criteria:

• pregnancy
• use of anti-histamine or dopamine antagonist as outpatient and/or within last 24 hours of presentation
• previous adverse reaction to study medications
• use of opioid medications prior to study start time within that ED visit