The makers of Maalox have agreed to change the name of one of its stomach medications, after U.S. health regulators reported at least five serious events from product mix-ups. But there are no plans to change the labels of a similar Maalox product sold in Canada.

On Wednesday, the U.S. Food and Drug Administration warned about the potential for serious side effects from mistakenly using Maalox Total Relief instead of other Maalox antacid products.

In Canada, Maalox Total Relief is marketed as Maalox Multi-Action.

Both products contain bismuth subsalicylate, a drug that is chemically related to ASA (often sold as Aspirin), and may cause similar adverse side effects, including stomach bleeding.

The drug should not be used by people with a history of gastrointestinal ulcers or bleeding disorders. It also should not be taken patients taking certain medications, such as blood thinners, anti-inflammatory pain relievers, such as ibuprofen, or oral anti-diabetic medications.

Maalox Advanced Regular Strength and Maalox Advanced Maximum Strength, on the other hand, contain antacid ingredients, such as aluminum hydroxide, magnesium hydroxide, and simethicone.

"Maalox Total Relief and Maalox are not interchangeable and shouldn't be used in place of each other," warned Carol Holquist, director of FDA's Division of Medication Error Prevention and Analysis.

"Consumer confusion and incorrect product use due to name confusion are serious public health issues."

In the U.S., Novartis, which makes the Maalox products, has agreed to change the name of Maalox Total Relief, dropping the name "Maalox" from the label, to avoid confusion. The rebranded product should be available in the U.S. by September.

But Novartis says it has no plans to change the labelling of Maalox Multi-Action in Canada, even though the product also contains bismuth subsalicylate.

"Health Canada has taken no action related to the Canadian version of this product, Maalox Multi-Action. Novartis Consumer Health is committed to working with Health Canada should they express any similar concerns in the future," Novartis Consumer Health Communications Director Julie Masow told CTV.ca in an email.

"Maalox Multi-Action is safe and effective when used as directed on the product label, and is labeled in accordance with all regulatory requirements," she added.

The new labelling in the U.S. won't appear until September. Until then, Novartis has agreed to a public education program to warn consumers and doctors about the difference between the two products.

Meanwhile, the FDA is warning manufacturers not to market products that have different active ingredients yet similar labelling.

"The FDA is concerned about the public health impact of medication mix-ups for products that have the same names or portions of the same name, but contain different active ingredients," said Holquist.

"We want companies to consider the potential for name confusion when choosing names for their drugs."

To help avoid the potentially serious health risks from Maalox product mix-ups, the FDA recommends that consumers:

  • Check with a health care professional or pharmacist if they are not sure what Maalox product is right for them.
  • Carefully look at the labels of all Maalox products to make sure the right product is being purchased for the right condition.
  • Read the active ingredients, uses and warnings on the package prior to purchasing.
  • Report any side effects from the use of Maalox products. In Canada, consumers can report bad reactions or side effects to Health Canada through its Canada Vigilance Program.