Five reports have been made to the Food and Drug Administration (FDA) regarding serious adverse effects stemming from use of the over-the-counter (OTC) product Maalox Total Relief, which is used to treat diarrhea, upset stomach associated with nausea, heartburn, and gas caused by overeating. The active ingredient is bismuth subsalicylate, rather than the aluminum hydroxide, magnesium hydroxide, and simethicone found in the older Maalox products, such as Maalox Advanced Regular Strength and Maalox Advanced Maximum Strength. Bismuth subsalicylate is an aspirin-related product and may increase the risk of bleeding in the same way that aspirin does; it may also have other adverse effects similar to those caused by aspirin. Bismuth subsalicylate should therefore not be used by people who have (or have a history of) gastrointestinal ulcers or a bleeding disorder; are taking blood-thinning medications such as warfarin (Coumadin) or clopidogrel (Plavix), nonsteroidal antiinflammatory drugs such as ibuprofen or naproxen, antidiabetic medications (because glucose control may be affected); or are children or adolescents recovering from a viral infection (because of the risk of Reye's syndrome).

Mistaken use of Maalox Total Relief has been attributed to similarities in the names and packaging of other Maalox products. (To see photos of the packaging on the FDA's Web site, go to http://bit.ly/biYHXc.) The manufacturer of Maalox has agreed to change the name (removing the brand name "Maalox") and the picture on the product container; the revised product will be available for sale in September 2010.

NPs who prescribe Maalox as an antacid should write out the entire product name (not just "Maalox"), including the active ingredient. Any nurse recommending a Maalox product should make sure that patient education for drug therapy includes information on OTC products. If adverse effects or medication errors occur in relation to this or another OTC product, including errors related to confusing packaging, nurses should report the event to the FDA's MedWatch voluntary reporting program at http://bit.ly/bW5WC.