Prescription drugs’ inactive ingredients can cause reactions

Prescription drugs’ inactive ingredients can cause reactions


Your prescription medication could be making you sick, and the culprit might not be the drug itself. That’s because most prescription drugs contain at least one inactive ingredient that can cause a reaction in some people.

These inactive ingredients, recent research shows, pose a potential risk to people who can’t tolerate gluten or lactose as well as those who are allergic to food dyes or other substances. The ingredients can also aggravate symptoms in people who have irritable bowel syndrome.

The findings by Harvard University researchers were published in the journal Science Translational Medicine.

Reactions to inactive ingredients in medication can range from minor to occasionally significant. The researchers noted that some medications contain gluten, which can damage the intestinal tract in celiac disease patients. In other cases, some people developed severe diarrhea because their pills contained lactose.

Medications typically have inactive ingredients to help with pill production or to alter the speed at which the drug is absorbed by the body.

The ratio of active to inactive ingredients can be significant in some medications: One cholesterol-reducing drug is composed of 99.3 percent inactive ingredients. In another instance, allergic reactions to a food dye were documented in about 4 percent of participants in a research study. About one-third of medications contained a food dye and 45 percent were found to have lactose. Even more common was a particular sugar that can cause minor gastrointestinal issues.

Fortunately, there’s a way to be vigilant: The U.S. Food and Drug Administration maintains a database that lists all ingredients in medications.

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