With triple-digit or near triple-digit days being common in Austin during the summer, people who take certain medications and supplements should be aware of what kind of interactions the heat can have with these drugs, according to Dr. Jodie Pepin, clinical pharmacy program director at Harbor Health.


Pepin said there are three main ways medicine can affect you when they interact with heat: cause dehydration; make the skin more photosensitive, or susceptible to burns and rashes; and restrict the vascular system, which reduces the ability to sweat and naturally cool down.

“A lot of medications in different classes usually do one of those three things that can make it dangerous for people out in the sun, especially if you're exercising or losing fluids and not staying hydrated, and not wearing sunscreen,” Pepin said.

Some medications to keep in mind include:
  • Beta-blockers for blood pressure or cardiac conditions; decongestants; and ADHD medicine, such as Adderall and Ritalin, could cause heat sensitivity and not allow your body to cool itself properly.
  • Laxatives and some diabetes medicines could increase your risk of dehydration.
  • Antihistamines; supplements, such as St. John’s Wort and vitamin B6; and nonsteroidal anti-inflammatories, or NSAIDS, such as ibuprofen and naproxen, could create an increased risk of sunburn and rashes.
Pepin said these interactions are more related to the drug and its mechanism of action, not the dosage. Additionally, there are more prescription medications that people will have trouble with, and those that cause photosensitivity are usually labeled as such on the bottle.

Major takeaways

While Pepin said the following are good rules of thumb for anyone to follow during the summer, anyone taking medications that could have harmful interactions with the heat should:
  • Wear sunscreen and reapply often, especially during water activities and other outdoor activities that cause sweating—even if they’re labeled as "waterproof" or "sweat proof."
  • Drink plenty of water, and replace electrolytes lost from urinating or sweating with electrolyte formulas such as Pedialyte instead of Gatorade.
  • Watch to make sure their body is not overheating.
Keep in mind

Pepin also reminded medication users to never leave prescriptions in the car, and to store them at room temperature as fast as possible.

“Even if you're going to take it with you on a picnic or something because you have to take it, it's better to keep it in a cool, dry place because a lot of drugs get degraded by heat, and humidity sometimes is a big problem,” Pepin said.