For years the EP’s first choice for treating gastritis, Reglan should be used with caution if patients have Parkinson’s disease or are on antipsychotics.
Nausea, vomiting, gastroparesis and migraine. Typical dose is 10-20mg PO, IV, or IM.
RECENTLY IN THE NEWS
Numerous studies have shown that metoclopramide was the clear first choice of emergency physicians for treating gastritis . How- ever, earlier this year, a randomized controlled trial of ondansetron (Zofran), metoclopramide, and a placebo, showed there was no statistically significant difference in the reduction of nausea severity between the three2. Metoclopramide, however, has been shown to be better than a placebo for the treatment of migraine head- aches .
HOW IT WORKS
It binds to and antagonizes D2 dopamine receptors, as well as 5-HT3 and 5-HT4 serotonin receptors. Its anti-emetic effects come from the anti-dopaminergic activity on the chemoreceptor trigger zone of the medulla. It is also gastroprokinetic, relaxes the pyloric sphinchter, and tightens the lower esophageal sphinchter, making it an ideal choice for patients with gastroparesis.
It was first described in 1964 in Europe, and has been sold in the US since 1982.
Acutely, metoclopramide may cause sedation, hypertension, and parkinsonism. It can also cause an acute dystonic reaction after 24-48 hours of use, particularly in young adults and children. Neuroleptic malignant syndrome is rare but possible. You should avoid this medication in patients with pheochromocytoma. Use with caution in patients with Parkinson’s disease, patients who are on anti-psychotics, and those with depression. If a patient comes in vomiting and you suspect a bowel obstruction, use a different agent. The gastroprokinetic activity of metoclopramide will cause the intestines to squeeze against a fixed obstruction and worsen the pain. In addition, about 20 percent of patients experience transient akathisia after taking metroclopramide. Although uncomfortable, it is easily treated with diphenhydramine.
BLACK BOX WARNING
Metoclopramide carries a black box warning for the risk of tardive dyskinesia. The risk is higher with prolonged administration (over 12 weeks), in women, in the elderly, and in those with diabetes. Numerous law firm websites are searching for patients who have experienced tardive dyskinesia from metoclopramide use. So be sure to discuss the risks and benefits of the medication if you send someone out with a longer prescription.
Pregnancy: Class B – probably safe.
Lactation: It is generally considered safe in lactation, and is even used in some patients to increase breast milk production, since dopamine antagonism will promote hypothalamic prolactin secretion 
For older adults, use the lower end of the dose range and use caution if combining with other potentially sedating medications. For those with a creatinine clearance less than 40mL/min, use 50% of the usual dose.
IV doses cost about $0.60 per dose. The 10mg metoclopramide tablets are on both the Walmart and Target $4 lists.
1. Mee et al. Treatment and assessment of emergency department nausea and vomiting in Australasia: A survey of anti-emetic management. Emerg Med Australas. 2011
2. Egerton-Warburton et al. Antiemetic use for nausea and vomiting in adult Emergency Department patients: Random- ized controlled trial comparing ondansetron, metoclopramide, and placebo. Ann Emerg Med May 2014
3. Colman et al. Parenteral metoclopramide for acute migrane: meta-analysis of randomised controlled trials. BMJ 2004
4. Hale, TW, Medications and Mothers’ Milk, 2012