Key TakeawaysSome medications can cause new side effects when you take them and are exposed to extreme heat.These side effects include dehydration, electrolyte imbalance, skin rash, and more.It’s important to know whether any of your medications may work differently in extreme temperatures so you can monitor your outdoor time appropriately, experts said.

Key Takeaways

Some medications can cause new side effects when you take them and are exposed to extreme heat.These side effects include dehydration, electrolyte imbalance, skin rash, and more.It’s important to know whether any of your medications may work differently in extreme temperatures so you can monitor your outdoor time appropriately, experts said.

Heat wavesbring many health risks likeheat stroke, heat exhaustion, anddehydration—but your medications may also cause issues on extremely hot days.

It’s essential to understand whether any medications you take can cause these side effects since they can worsen if you spend excess time outside. “Increased exposure [to heat] brings increased risk,”Nicholas Kman, MD, FACEP, an emergency medicine physician at The Ohio State University Wexner Medical Center, told Verywell.

Medications That Can Cause Side Effects During Hot Weather

Disrupt Thermoregulation and Fluid Balance

Medications that affect your thermoregulation and fluid balance “can amplify the risk of harm from hot weather,” Kman said, explaining that they include the following drugs:

Antipsychotic medications are often recommended for people with schizophrenia, major depressive disorder with psychotic features (such as delusions and hallucinations), acute mania, borderline personality disorder, and more.Examples of antipsychotic medications that can cause side effects in extreme heat include Haldol (haloperidol), Zyprexa (olanzapine), and Seroquel (quetiapine).

Tricyclic antidepressants (TCAs) that can cause harmful side effects in the heat include amitriptyline and Anafranil (clomipramine). TCAs are used to treat major depressive disorder.

Antihypertensive drugs are used to treat cardiovascular issues, and medications in this category include diuretics, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor-neprilysin (ARN) inhibitors.

In very hot weather, these medications may cause symptoms such as electrolyte imbalance, dehydration, and volume depletion (when you lose too much fluid), Kman said. They can also increase your risk of falls, and some of the above may dilate your blood vessels, worsening dizziness, he added.

Consuming alcohol, caffeine, or sugary drinks can exacerbate these side effects since all of these substances can further dehydrate you, Redlener said.

GLP-1 MedicationsGlucose-like peptide 1 (GLP-1) medications like Ozempic and Wegovy can cause vomiting and diarrhea; therefore, taking the drugs in extreme heat may lead to dehydration.

GLP-1 Medications

Glucose-like peptide 1 (GLP-1) medications like Ozempic and Wegovy can cause vomiting and diarrhea; therefore, taking the drugs in extreme heat may lead to dehydration.

Increase Sun Sensitivity

Medications that can increase sun sensitivity include the following, Kman said:

Antibiotics that can create uncomfortable side effects in the sun include Metrogel (metronidazole), which is used to treat infections of the gastrointestinal tract, heart, reproductive system, joints, skin, blood, lungs, and more.

When you use these medications and spend time in the sun, you may develop a rash similar to sunburn.

Become Less Effective

Heat can damage the following medications, Redlener said:

EpiPens can deliver lessepinephrine—the agent that treats allergic emergencies—in hot temperatures. Insulin, a medication that helps people manage diabetes, is intended to be stored in a refrigerator and can become less effective in the heat. Inhalers, used to treat asthma, can burst when exposed to heat.

The above aren’t the only medications that can increase the risk of side effects on hot days; high temperatures can affect a range of drugs, including some anti-seizure medications, antiretrovirals, analgesics, antihistamines, and more.

If you think a medication you’re taking is causing side effects in the heat, it’s important to speak with a healthcare provider like a doctor or pharmacist, experts said.

Some people are more likely to experience these side effects. “Older adults, the very young, and people with mental illness and chronic disease are at highest risk,” Kman said. “That said, even young and healthy people can be affected if they participate in strenuous physical activities during hot weather.”

Because risk increases with heat exposure, “we get concerned about athletes, [people who are] homeless, and people who work in hot environments,” Kman added.

The following symptoms could indicate that you’re experiencing heat stroke and should prompt an emergency room visit, Kman said:

Any heat-related side effects of medications warrant a discussion with a healthcare provider, no matter the severity, experts said. A healthcare provider may be able to alter your medication regimen during warmer months or suggest ways to manage or treat the side effects.

The key to preventing these side effects may be to monitor your time in hot environments. “There is a lot of public health messaging about when to go outside, and there are heat indexes that a lot of public health agencies are promoting,” Redlener said. It’s important to keep up with the weather in your area and follow the guidance of local health authorities, he said.

What This Means For You

8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Heat and medications—guidance for clinicians.Chokhawala K, Stevens L.Antipsychotic medications. In:StatPearls. StatPearls Publishing; 2024.Bettge K, Kahle M, Abd El Aziz MS, Meier JJ, Nauck MA.Occurrence of nausea, vomiting and diarrhoea reported as adverse events in clinical trials studying glucagon-like peptide-1 receptor agonists: a systematic analysis of published clinical trials.Diabetes Obes Metab. 2017;19(3):336-347. doi:10.1111/dom.12824National Library of Medicine: MedlinePlus.Metronidazole.National Institutes of Health (NIH).Tetracycline.National Library of Medicine: MedlinePlus.Griseofulvin.Padda IS, Parmar M.Flucytosine. In:StatPearls. StatPearls Publishing; 2024.Vaidyanathan A, Gates A, Brown C, Prezzato E, Bernstein A.Heat-related emergency department visits - United States, May-September 2023.MMWR Morb Mortal Wkly Rep. 2024;73(15):324-329. doi:10.15585/mmwr.mm7315a1

8 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Heat and medications—guidance for clinicians.Chokhawala K, Stevens L.Antipsychotic medications. In:StatPearls. StatPearls Publishing; 2024.Bettge K, Kahle M, Abd El Aziz MS, Meier JJ, Nauck MA.Occurrence of nausea, vomiting and diarrhoea reported as adverse events in clinical trials studying glucagon-like peptide-1 receptor agonists: a systematic analysis of published clinical trials.Diabetes Obes Metab. 2017;19(3):336-347. doi:10.1111/dom.12824National Library of Medicine: MedlinePlus.Metronidazole.National Institutes of Health (NIH).Tetracycline.National Library of Medicine: MedlinePlus.Griseofulvin.Padda IS, Parmar M.Flucytosine. In:StatPearls. StatPearls Publishing; 2024.Vaidyanathan A, Gates A, Brown C, Prezzato E, Bernstein A.Heat-related emergency department visits - United States, May-September 2023.MMWR Morb Mortal Wkly Rep. 2024;73(15):324-329. doi:10.15585/mmwr.mm7315a1

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Centers for Disease Control and Prevention.Heat and medications—guidance for clinicians.Chokhawala K, Stevens L.Antipsychotic medications. In:StatPearls. StatPearls Publishing; 2024.Bettge K, Kahle M, Abd El Aziz MS, Meier JJ, Nauck MA.Occurrence of nausea, vomiting and diarrhoea reported as adverse events in clinical trials studying glucagon-like peptide-1 receptor agonists: a systematic analysis of published clinical trials.Diabetes Obes Metab. 2017;19(3):336-347. doi:10.1111/dom.12824National Library of Medicine: MedlinePlus.Metronidazole.National Institutes of Health (NIH).Tetracycline.National Library of Medicine: MedlinePlus.Griseofulvin.Padda IS, Parmar M.Flucytosine. In:StatPearls. StatPearls Publishing; 2024.Vaidyanathan A, Gates A, Brown C, Prezzato E, Bernstein A.Heat-related emergency department visits - United States, May-September 2023.MMWR Morb Mortal Wkly Rep. 2024;73(15):324-329. doi:10.15585/mmwr.mm7315a1

Centers for Disease Control and Prevention.Heat and medications—guidance for clinicians.

Chokhawala K, Stevens L.Antipsychotic medications. In:StatPearls. StatPearls Publishing; 2024.

Bettge K, Kahle M, Abd El Aziz MS, Meier JJ, Nauck MA.Occurrence of nausea, vomiting and diarrhoea reported as adverse events in clinical trials studying glucagon-like peptide-1 receptor agonists: a systematic analysis of published clinical trials.Diabetes Obes Metab. 2017;19(3):336-347. doi:10.1111/dom.12824

National Library of Medicine: MedlinePlus.Metronidazole.

National Institutes of Health (NIH).Tetracycline.

National Library of Medicine: MedlinePlus.Griseofulvin.

Padda IS, Parmar M.Flucytosine. In:StatPearls. StatPearls Publishing; 2024.

Vaidyanathan A, Gates A, Brown C, Prezzato E, Bernstein A.Heat-related emergency department visits - United States, May-September 2023.MMWR Morb Mortal Wkly Rep. 2024;73(15):324-329. doi:10.15585/mmwr.mm7315a1

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