Heat Stroke Is a Side Effect of Several Medications; Here's What You Need to Know

As the San Fernando Valley’s annual heat wave hits triple digits, you know the drill: Drink plenty of water, wear sunscreen, and avoid direct sun during peak hours. But did you know that your daily prescriptions and over-the-counter medications can also be a risk factor? 

Certain commonly prescribed drugs, as well as over-the-counter medications, can interfere with your body’s natural ability to regulate temperature, putting you at significantly increased risk for heat exhaustion and life-threatening heat stroke. 

Samuel Fink, MD, in Tarzana, California, is well-versed in how medications interact with high temperatures, and he routinely helps our patients manage their medications, including evaluating them for side effects such as heat stroke. 

In this blog, Dr. Fink breaks down how medications affect your body’s ability to regulate heat, which medications pose a risk of heat stroke, and how to stay safe.

How medications affect your body’s cooling system

To stay cool, your body relies primarily on two mechanisms: sweating and increasing blood flow to the skin to allow heat to escape. Certain medications can impair these vital responses in several distinct ways:

Reducing sweat production

Drugs known as anticholinergics block acetylcholine (a key chemical messenger), which inhibits sweat glands. Without adequate sweating, your body cannot cool itself efficiently.

Impairing blood flow

Certain cardiovascular medications prevent the body from directing blood flow to the skin's surface, limiting natural heat dissipation.

Causing dehydration

Diuretics encourage the body to expel excess fluid and sodium, which can quickly lead to dehydration and impair overall heat tolerance.

Blunting thirst cues

Some medications alter brain signaling, reducing your perception of thirst so you don't realize your body needs fluids until it is already dehydrated.

Common medications that increase heat risk

A wide variety of routine prescriptions and over-the-counter drugs can heighten your susceptibility to heat stroke. Some of the most common categories include:

Blood pressure medications

Beta-blockers reduce heart rate and restrict skin blood flow, while ACE inhibitors and diuretics increase the risk of dehydration.

Antidepressants and antipsychotics

SSRIs, SNRIs, and tricyclic antidepressants can suppress sweating and affect the brain's central thermoregulation center (the hypothalamus).

Allergy and cold remedies

Over-the-counter antihistamines (such as diphenhydramine) and oral decongestants can reduce sweating and elevate baseline body temperature.

Bladder control drugs

Medications used for overactive bladder frequently exhibit strong anticholinergic properties that block sweat production.

ADHD medications

Stimulants can increase body heat production and metabolic rate while constricting blood vessels.

Some medications make it tough to cool down, but others — like Adderall, Ritalin, and illegal substances like ecstasy, cocaine, and methamphetamine — elevate your body heat.

How to protect yourself in the heat

If you take any of these medications, you do not need to stop taking them. In fact, abruptly stopping prescription medications can be dangerous. 

Instead, keep cool by staying hydrated and avoiding consuming excessive alcohol and caffeine, which exacerbate fluid loss. Limit strenuous exercise or outdoor chores during the peak heat hours of midday and early afternoon. 

You can also make an appointment with Dr. Fink to evaluate your medications. Call our office at 818-609-0700 or request an appointment online today.