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Medicines can increase risk of heat stroke

August 9, 2018

MINNEAPOLIS, Minn. – Our bodies naturally work to prevent us from overheating. However, common medicines, including some over-the-counter drugs, can increase your risk of heat exhaustion, heatstroke or serious sunburn. HealthPartners pharmacist Larry King, PharmD, says that some ways that medicines can affect you on hot days including the following:

  • Decrease sweating. Some medicines decrease the body’s ability to sweat and cool itself off. Examples include some antidepressants and anti-psychotic mediations, medicines for Parkinson’s disease, Benadryl, and other cold and allergy medicines.
  • Dehydration. Some medicines remove water and electrolytes from the body. That increases the risk of heat exhaustion. Examples of these medicines include medicines to lower high blood pressure, pills to reduce fluid retention, and caffeine and alcohol. Medicines that cause diarrhea or vomiting can also increase the risk for dehydration.
  • Raise the level of drugs in your body. Some medicines work only if taken at a precise dose. If you become dehydrated, it can cause the drug level to be too high. This can cause negative side effects such as vomiting, weakness and confusion. Examples of these medicines include medicines to treat bipolar disorder, some heart conditions such as atrial fibrillation and some anti-seizure medicines. It also includes medication delivered from patches for conditions such as pain and high blood pressure.
  • Decrease your skin’s ability to cool down. Some medicines decrease the amount of blood that flows to the skin, making it harder to get rid of excessive heat. Examples include beta blockers used to treat heart conditions and some blood pressure medicines.
  • Increase your body temperature. Stimulant medicines used to treat ADHD cause your body to produce more heat. Examples of legal medicines include Adderall and Ritalin. Illegal stimulants include cocaine, ecstasy and methamphetamine.
  • Increase your risk of sunburn. Some medicines make your skin more sensitive to the sun to sunburn. These include acne medicines (Retin-A and Tazorac) and antibiotics such as Bactrim and tetracyclines.
  • Decrease effectiveness of medication. Keeping medicines in a hot car on hot days could make them less effective. It’s especially important to avoid for life-saving medicines including nitroglycerin used to treat heart conditions.

Patients who take any of these medicines should talk to their pharmacist to learn about any potential side effects. Steps that you can take to reduce the risk of heat problems include drinking plenty of water or fluids, staying in the shade when outdoors, avoiding the outdoors especially during midday and wearing a hat when in the sun.

About HealthPartners

HealthPartners is a consumer-governed, non-profit health care organization with a mission to improve health and well-being in partnership with members, patients and the community. For more information, visit

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