Harvard Women's Health Watch

What's hiding in your medicines?

Salt, sugar, and other unexpected ingredients could be lurking where you least expect them.

Thanks to public health campaigns, most of us are well aware that added salt and sugar in our food are not good for our health. But what about the sugar and salt that's in our medicine cabinets? Some of the drugs we take can be hidden sources of these and other additives.

A British study published in December 2013 found that people who took effervescent versions of medicines—such as the pain relievers acetaminophen and aspirin—faced a higher risk for heart attacks, strokes, and other cardiovascular events than people who didn't take these drugs. The culprit behind the participants' heart troubles? High sodium levels in the medication.

Along with the main active ingredient in medications, there can be many more inactive components, which are sometimes referred to as excipients. Drug manufacturers add preservatives, dyes, flavorings, sweeteners, bulking agents, and other inactive ingredients to give medicines a more pleasant taste, look, or texture; protect them from bacterial invasion; and prolong their shelf life.

The FDA has approved more than 700 different additives for use in prescription and over-the-counter drugs. Although these ingredients are required to be safe for human consumption, they may not be safe for everyone. Excess sodium can cause heart problems in those at risk for heart disease. Sugar can spell trouble for people with diabetes. Dyes can lead to allergic reactions. Starches can trigger a reaction in people with celiac disease or gluten sensitivity. Tablets that use the milk sugar, lactose, as a binder can be trouble for people with lactose intolerance.

Take precautions

So what can you do to avoid having an unexpected drug reaction? Whenever you get a new prescription, read through the patient information materials to check for any possible allergy alerts. Ask your doctor and pharmacist about both the active and inactive ingredients, especially if you have a known allergy.

At least once a year, it's helpful to sit down with your doctor or pharmacist and go over the list of all the medicines you take—both prescription and over-the-counter—to make sure none of the drugs on your list could potentially interact or cause unintended side effects.