Heat and medications don’t mix
Published on Friday, August 1, 2025
By: Gary Pettus, gpettus@umc.edu
As the Mississippi sun continues its pitiless summer assault, be advised that many medications millions of Americans take don’t like the high heat any more than you do.
Some of these treatments weaken the body’s ability to tolerate soaring temperatures, while many lose their power to heal when not stored properly.
These drugs include many sold over the counter, such as aspirin, on top of the health- and life-saving medicine taken by prescription.
Whatever remedies you depend on, experts at the University of Mississippi Medical Center urge you to be heedful of the heat.
“The medications that I most commonly prescribe, which can cause an increased risk of heat-related illness, include antihistamines [for allergies], beta-blockers [for heart disease], benzodiazepines [for anxiety], calcium channel blockers [for high blood pressure], diuretics [for blood pressure control] and SSRIs [selective serotonin uptake inhibitors, for depression],” said Dr. Jessica Lavender, UMMC associate professor of medicine and an internal medicine specialist.
“Diuretics are the ones we all think about as causing heat-related illness due to increased loss of fluids; however, laxatives, which are typically over the counter, can cause a similar issue,” Lavender said.
“Less commonly known: Medications like antidepressants can interfere with your body’s ability to regulate temperature. Also, antihistamines can limit your body’s ability to cool itself.”
When your body loses that cooling ability, you’re at risk of heat exhaustion and heat stroke, Lavender said. “But other things can occur prior to these serious conditions such has heat syncope [fainting] and cramps.”
Many drugs can compound the risk of sunburn, such as antibiotics, antifungals and medications for high blood pressure, said Dr. Deborah Minor, UMMC professor of medicine and a Doctor of Pharmacy.
Because many older people take five medications or more – known as polypharmacy – they are even more likely to sicken from the heat, Minor said.
“A domino effect occurs because of chronic diseases and conditions such as declining kidney, heart, vascular and cognitive function,” she said.
Commonly-used drugs that don’t require a prescription are temperamental in high temperatures, too. “NSAIDs are among these over-the-counter medications,” Minor said. Nonsteroidal Anti-Inflammatory Drugs include aspirin, ibuprofen and naproxen sodium (Aleve).
“These meds decrease blood flow to the kidneys,” Minor said. “Many people do not understand or consider the risk associated with excessive heat exposure or dehydration.
“Being on other meds that can cause kidney problems, or those that are eliminated by the kidneys, compounds the risk of kidney injury.”
Warning signs of an over-heated body include fatigue, weakness, nausea, headache and dizziness, Lavender said.
“If you notice someone who has been outside, especially in this heat, with symptoms of confusion or you witness them having a seizure, this should raise your concern for heat-related illness.
“If you notice someone is hot and dry, meaning they have stopped sweating, they should certainly take caution.”
For milder symptoms, a remedy is moving to a cooler place and trying to rehydrate, Lavender said. “For those with more severe symptoms, such as a fever of 105 degrees or greater, they need to be seen in the emergency department.
“Often, during the summer months, I will tell patients to be sure they are keeping well hydrated and to let me know if they fall ill with, say, a stomach virus. Or if they will be cutting grass a good bit during the summer months.
“This helps us come up with a game plan to stay well without compromising their treatment plan.”
It’s also vital to protect the medications themselves. “Most should be stored at room temperature, though 5-10% require refrigeration or even freezer storage,” Minor said.
“It is important to know how a medication should be stored to maintain efficacy, sterility and form – physical integrity. Besides loss of effectiveness, improper storage can possibly cause you harm.”
Insulin, in particular, should be kept away from intemperate temperatures – do not store those medications near extreme heat or extreme cold, or in the freezer, direct sunlight or the glove compartment of a car, cautions the American Diabetes Association.
“For all medications, follow storage instructions and pay attention to temperature and even humidity recommendations,” Minor said. “For instance, do not store it in the bathroom.”
Many drugs that require refrigeration in the pharmacy may be stored at room temperature after they are dispensed, Minor said. Others may have to be refrigerated after they are dispensed. Those include unopened Ozempic pens – prescribed for type 2 diabetes.
Ozempic, insulins and amoxicillin suspension – a treatment for some bacterial infections – are among those with a limited shelf life after a change in storage, Minor said.
“After this period, which can vary from days to months, meds should be discarded because they are no longer effective or may cause harm.”
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To make an appointment with a UMMC primary care specialist, call 601-815-2005, or go online here. To make an appointment specifically with a general internal medicine physician, call 601-855-4717 for the UMMC Madison location; or call 601-984-5660 for Colony Park South in Ridgeland and Grants Ferry in Flowood locations.
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