Medications That Are Not Fun In The Sun

Summer is in full swing – and you may be looking at how to stay cool! There are certain medications that cause heat intolerance and have dangerous side effects as temperatures skyrocket. 

Heat intolerance is more than just feeling uncomfortable when temperatures rise. It is a condition that occurs when your body cannot regulate its temperature properly.

As temperatures rise, a part of your brain, known as the hypothalamus, sends messages through your nerves that tell your skin to cool off by sweating. The moisture evaporates off your skin and allows your core temperature to decrease. If something disrupts this process, your body is unable to cool down and that can lead to unpleasant symptoms, like nausea or dizziness, or even a heat-related illness.

Many different factors play a part in your tolerance to heat. This includes certain health conditions, age, weight and even the medication you take. So, let’s take a closer look at the medications that can increase your sensitivity to heat.

Blood Pressure Medications

Certain prescriptions for high blood pressure can make you susceptible to heat intolerance, especially thiazide diuretics and beta blockers. 

Diuretics force fluid out of our bodies through our kidneys to control high blood pressure and heart failure. These medications could cause dehydration and therefore, making you more at risk of overheating and heat-related illness. Meanwhile, beta blockers can decrease blood flow to the skin, which can inhibit sweating. 

Examples of these medications include chlorthalidone, Microzide (hydrochlorothiazide), Toprol XL (metoprolol) and Inderal (propranolol).

 

This medicine is very effective at stopping sniffling, sneezing and itchy eyes. However, it can also prevent you from sweating. Antihistamines produce what is called the “drying” effect. The same mechanism that allows antihistamines to slow mucus production is also responsible for your body producing less sweat. When you cannot sweat, it is difficult to regulate your internal temperatures when dealing with high external temperatures.

This “drying” effect is more common with first-generation antihistamines, like Benadryl, Dramamine and NyQuil. First-generation antihistamines are different than second-generation as they go through the blood-brain barrier and can cause sleepiness. They can also be considered not as safe to interact with other medications.

Second-generation antihistamines do not have the “drying” effect. This would include Claritin, Zyrtec and Allegra. 

 

Decongestants

Decongestants work the same way as blood pressure medications, which decrease the blood flow to the skin. This can be dangerous on an already hot day as it can inhibit sweating. This would include Sudafed or anything with pseudoephedrine. 

 

Overactive Bladder Treatments

Overactive bladder treatments, or anticholinergics, block the action of involuntary muscle movements that can make you feel like you need the restroom when you do not need it. Additionally, they can reduce sweating and your ability to cool off. This includes medications like Ditropan (oxybutynin) or Detrol (tolterodine). 

 

Certain prescriptions that treat attention deficit hyperactivity disorder (ADHD) fall into a class of medications known as stimulants. These medications raise your body temperatures and increase your risk for heat intolerance. On top of that, they physically constrict blood vessels and reduce blood flow to the skin. Blood flow needs to be increased to the skin to cool down.

These medications include Adderall (amphetamine/dextroamphetamine) and Ritalin (methylphenidate).

 

Psychiatric Medications 

Medications that are used to treat certain mental health conditions and Parkinson’s disease all effect the hypothalamus. This region of the brain is essential to cooling, so these medications can inhibit your ability to reduce body temperature on hot days. They can also decrease your thirst reflex, increasing dehydration. 

There are many different types of psychiatric prescriptions that can lead to heat intolerance:

 

Prevention of heat intolerance and heat-related illnesses is always the best treatment. You should take extra precautions before you head outdoors if you take any of these medications. These include:

The first sign of heat intolerance is feeling hot and uncomfortable. Other symptoms include:

When these signs appear, take steps to go indoors and cool off as soon as possible. Remove excess clothing, take sips of cool water and place cool compresses on your body. If you remain in the heat, you could develop symptoms such as rapid breathing, decreased sweating or an altered mental state. These symptoms can mean that your heat intolerance is progressing to a heat-related illness, such as a heat stroke, which will be fatal when untreated. 

When in doubt, drink a glass of water and sit down for a minute indoors. If symptoms do not subside quickly, it may be time to seek medical treatment. Be sure to keep a list of medications you are currently taking handy so that your treating physician can respond appropriately.


Source: WebMD, SingleCare.com
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Image: Vitamin D keeps you healthy while lack of sun. (FotoHelin via Shutterstock)