It’s crucial to pay attention to the often-overlooked side effect of medications during heat waves, which the Environmental Protection Agency says are increasing in both intensity and frequency. But one thing to remember that it’s not just those stifling stretches that can be dangerous. Research shows that older patients with chronic medical conditions who take heat-sensitive medications can have medication-related problems throughout the entire summer.
At 80 degrees to 90 degrees, the National Weather Service advises caution with prolonged exposure. Note that the heat index is calculated with temperatures in the shade but can increase by up to 15 degrees in direct sunlight.
There are a lot of different medications that can raise your risk of being susceptible to heat illness, and the potential issues they raise can vary. “One of the biggest issues is medications that block your ability to sweat,” says Lewis Nelson, M.D., chair of emergency medicine at Rutgers New Jersey Medical School.
“If you’re not able to sweat, you lose one of your body’s normal mechanisms to cope with getting hot,” explains Michael Levine, M.D., an emergency medicine physician at UCLA Health.
Several different medications can interfere with the body’s ability to sweat or by reducing blood flow to the skin. Medications can also cause dehydration, and some may make the skin more sensitive to the sun, causing a rash or sunburn.
Some individuals are more susceptible to these heat-related issues than others. According to AARP, risk factors include being over 65, having chronic medical conditions and being overweight. Spending time outside during the warmest part of the day — especially if you are doing yard work, physical activity or exercise — also increases your risk.
Below are some examples of commonly used medications that can make it harder for your body to handle the heat.
1. Heart medications
Prescribed for high blood pressure and blood clot prevention and to support the pumping function of the heart.
- Diuretics (also called water pills): furosemide (Lasix), chlorthalidone (Hygroton), hydrochlorthiazide (Microzide, HydroDiuril)
- Beta blockers: metoprolol (Toprol, Lopressor), atenolol (Tenormin), carvedilol (Coreg), propranolol (Inderal)
- ACE Inhibitors: lisinopril (Zestril, Prinivil)
- Angiotensin II receptor blockers (ARBs): losartan (Cozaar), valsartan (Diovan)
- Antiplatelets: clopidogrel (Plavix)
2. Antidepressants
Prescribed to treat depression and anxiety.
- Selective serotonin reuptake inhibitors (SSRIs): citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft)
- Serotonin–norepinephrine reuptake inhibitors (SNRIs): duloxetine (Cymbalta), Venlafaxine (Effexor XR)
- Tricyclic antidepressants: amitriptyline (Elavil), nortriptyline (Pamelor)
3. Antipsychotics
Prescribed for schizophrenia, bipolar disorder and other mental health disorders.
Examples: risperidone (Risperdal) Quetiapine (Seroquel), Haloperidol (Haldol), Olanzapine (Zyprexa)
4. Central nervous system stimulants
Prescribed for attention deficit hyperactivity disorder (ADHD).
Examples: dextroamphetamine (Adderall), methamphetamine (Desoxyn), methylphenidate (Ritalin)
5. Anticholinergics
Prescribed for Parkinson’s disease and overactive bladder.
Examples: benztropine (Cogentin), oxybutynin (Ditropan XL), tolterodine (Detrol)
6. Antihistamines
Used for seasonal allergies, bug bites and beestings.
Examples: diphenhydramine (Benadryl)
7. Decongestants.
Used for the common cold and allergies.
Examples: pseudoephedrine (Sudafed), phenylephrine (Sudafed PE), Oxymetazoline nasal spray (Afrin, Zicam, Dristan, Mucinex)
8. Dopaminergics.
Prescribed for Parkinson’s disease.
Examples: carbidopa/levodopa (Sinemet)
If you are taking a medication that can be problematic in the heat, it’s a good idea to set aside time to discuss this with your doctor and hatch a plan for hot-weather days.
How to stay safe in the heat when you take these medications
If you’re taking prescription medication, it’s important to continue to take it as directed by your doctor, Dr. Levine says. “Don’t not take medications that are prescribed to you,” he says. “If you are going to stop medications, it should be done in conjunction with your physician.”
Dr. Nelson agrees. “You should take your medications, but shouldn’t put yourself in a situation where you could overheat,” he says. If you can, Inteso recommends staying indoors when temperatures get especially high. But if you need to venture out, she suggests that you “try to stay in the shade, consider a portable fan, stay hydrated, and take breaks from being outside.”
Dr. Levine also recommends having a low threshold for getting into cooler temperatures. “Be aware of your surroundings and your body,” he says. “If you start to get too hot, stop what you’re doing and come inside.”