How to Treat Cold and Flu Symptoms If You Have Diabetes

Which medications to take and which to avoid

Diabetes raises your risk of catching a cold or the flu because it weakens your immune system. And when you're sick, it's harder to keep blood sugars under control.

While your body fights the illness, it releases hormones that increase blood sugars and interfere with insulin's blood-glucose-lowering effects. The last thing you need is for cold and flu medications to make your blood-sugar levels even higher.

This article looks at the cold and flu medications that are safe and those you should avoid.

Woman with cold blowing her nose in bed
Tom Stewart / Getty Images

Cold/Flu Medications and Diabetes

Not all cold and flu medications are safe when you have diabetes. The trick is to know what ingredients are in the medications you buy, and how they will affect your diabetes.

Ingredients on the labels fall under two categories: inactive and active.

  • Inactive ingredients don't have medicinal value. They're typically fillers, flavorings, colorings, and substances that help with consistency. 
  • Active ingredients are the drugs that actually treat the symptoms.

Inactive Ingredients and Diabetes

Alcohol or sugar are non-drug ingredients that may be in the cold and flu medicine you are taking. Both alcohol and sugar can raise your blood glucose levels.

They may be listed under "inactive ingredients" on the label. If inactive ingredients aren't listed, you may need to check the company's website or call them to ask.

If you're picking up medicine at the pharmacy, ask the pharmacist if it contains anything that could affect your blood sugars.

Recap

It's harder to manage blood sugars when you're sick. Cold and flu medications can affect your blood glucose levels. Be sure to check for inactive ingredients like sugar or alcohol.

Active Ingredients and Diabetes

The active ingredients are the medications. Some cold and flu remedies have one ingredient, but many of them are combinations of several drugs.

Be sure you're only taking the medications that fit your symptoms. For example, don't take a nighttime cold and cough medicine if you don't have a cough and you've been sleeping just fine.

Cold and flu products have a few common ingredients to be aware of.

Pain and Fever Reducers

Pain relievers can help with minor body aches, sinus pain, and headaches from a cold or flu. These same drugs can lower a fever.

Pain relievers you may take for a cold or flu include:

  • Acetaminophen: In Tylenol products and dozens of other cold/flu preparations. Can be toxic to your liver and kidneys. If you have kidney complications from diabetes, check with your healthcare provider before taking this drug.
  • Ibuprofen: A non-steroidal anti-inflammatory drug (NSAID). Should be used cautiously by people with liver and kidney problems. High doses may increase the blood-sugar-lowering ability of insulin and diabetes medications.
  • Naproxen: An NSAID. Don't use it if you have severe cardiovascular (heart) disease, or kidney or liver problems. High doses may increase the risk of hypoglycemia (low blood sugar) with insulin and diabetes medications.

Cough & Congestion Medications

Medicines for cough and congestion come in a few different types.

Suppressants and Expectorants

  • Dextromethorphan is a cough suppressant in many cough preparations. At recommended doses, it's believed to be safe for people with diabetes.
  • Guaifenesin is an expectorant and is also in many cough remedies. It's considered safe for people with diabetes.

Decongestants

Common decongestants include:

They're available in both nasal sprays and some oral cold medicines. They work by drying up secretions in the nasal passages.

They may decrease the effects of insulin or oral diabetes medications and lead to high blood sugars. They can also increase blood pressure. Use these with caution if you have diabetes.

Antihistamines

Antihistamines are allergy medications, but they sometimes help with cold and flu symptoms, as well.

Older antihistamines may cause low blood pressure in some people. They don't affect diabetes directly. However, people over 65 may be more susceptible to side effects.

These drugs also have a sedative effect, so they may not be safe to use during the day. They include:

They're common in combination products as well as single-drug formulations.

Second-generation antihistamines are considered safer than older ones. They don't cause sedation and have no diabetes-specific warnings. They include:

Summary

Blood glucose levels are more difficult to manage when you're sick. Not all cold and flu medications are considered safe for you.

Inactive ingredients may include sugar or alcohol. They may raise blood sugar levels.

Among active ingredients, pain relievers come with the most warnings. Decongestants may make diabetes drugs less effective. Cough suppressants, expectorants, and antihistamines are generally thought to be safe.

A Word From Verywell

Managing a chronic condition can be a lot of work. Being sick on top of that complicates things even more.

Before you take any cold or flu medications, check with your healthcare provider. They can guide you toward the ones that are safest for you.

Also, ask your pharmacist to look over your medications and check for possible interactions with cold and flu drugs. That way, you know you're doing what's best for your overall health.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Flu and people with diabetes.

  2. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases. Take care of your diabetes during sick days & special times.

  3. Pharmacy Times. Cough and cold products for patients with diabetes.

  4. Harvard Medical School, Harvard Health Publishing. 10 things you should know about common pain relievers.

  5. Li J, Zhang N, Ye B, et al. Non-steroidal anti-inflammatory drugs increase insulin release from beta cells by inhibiting ATP-sensitive potassium channels. Br J Pharmacol. 2007;151(4):483-93. doi:10.1038/sj.bjp.0707259

  6. National Institutes of Health, U.S. National Library of Medicine: MedlinePlus. Guaifenesin.

  7. Diabetes in Control. Drugs that can affect blood glucose levels.

  8. Drugs.com. Benadryl: 7 things you should know.

  9. Yanai K, Yoshikawa T, Yanai A, et al. The clinical pharmacology of non-sedating antihistamines. Pharmacol Ther. 2017;178:148-156. doi:10.1016/j.pharmthera.2017.04.004

Additional Reading

By Debra Manzella, RN
Debra Manzella, MS, RN, is a corporate clinical educator at Catholic Health System in New York with extensive experience in diabetes care.