Metoclopramide is used to treat heartburn and regurgitation; to prevent vomiting in people receiving drugs to treat cancer; and to prevent nausea, vomiting, heartburn, and fullness after a meal in certain individuals with diabetes.
Summary of Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem contradictory. For clarification, read the full article for details about the summarized interactions.
 May be Beneficial: Supportive interaction—Taking these supplements may support or otherwise help your medication work better. | Willow* |
 Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results. | N-acetyl cysteine* |
| Depletion or interference | None known |
| Side effect reduction/prevention | None known |
| Reduced drug absorption/bioavailability | None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Interactions with Dietary Supplements
N-acetyl cysteine
A single case report described a 15-year-old girl who suffered oxygen deprivation in her body tissues after being given high amounts of metoclopramide and N-acetyl-cysteine to treat her for an overdose of acetaminophen.1 It is unknown whether N-acetyl-cysteine supplementation in the absence of acetaminophen overdose could cause similar effects in people taking metoclopramide. Until controlled research determines the safety of this combination, it should be used only under the supervision of a qualified physician.
Interactions with Herbs
Willow (Salix alba)
Salicylic acid is a compound formed in the body from either aspirin or willow bark. Taking metoclopramide before aspirin or willow bark results in higher concentrations of salicylic acid and greater pain relief in people suffering from an acute migraine headache.2 Controlled studies are necessary to confirm the benefit of this interaction.
Interaction with Foods and Other Compounds –––
Lactose-containing foods
Individuals who have lactose intolerance (difficulty digesting milk sugar) may experience more severe symptoms while taking metoclopramide.3 Lactose is the milk sugar present in dairy products.
Caffeine
A single case report described a 42-year-old man taking metoclopramide who experienced mental depression after he abruptly quit using caffeine.4 People who are advised to quit caffeine should probably reduce their coffee or tea consumption gradually if they are taking metoclopramide.
Alcohol
Drinking alcohol while taking metoclopramide may significantly increase the amount and speed of alcohol absorption, resulting in enhanced alcohol effects such as drowsiness.5 Consequently, people taking metoclopramide should avoid alcohol, especially when staying alert is necessary.
References
1. Langford JS, Sheikh S. An adolescent case of sulfhemoglobinemia associated with high-dose metoclopramide and N-acetylcysteine. Ann Emerg Med 1999;34:538–41.
2. Miner JO. Drug interactions involving aspirin (acetylsalicylic acid) and salicylic acid. Clin Pharmacokinet 1989;17:327–44.
3. Peuhkuri K, Vapaatalo H, Nevala R, Korpela R. Influence of the pharmacological modification of gastric emptying on lactose digestion and gastrointestinal symptoms. Aliment Pharmacol Ther 1999;13:81–6.
4. Wenokur B, Lessem P. Caffeine withdrawal metoclopramide, and depression. Am J Gastroenterol 1993;88:1464 [letter].
5. Sifton DW, ed. Physicians Desk Reference. Montvale, NJ: Medical Economics Company, Inc., 2000, 2603–5.
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2006-09-07
