When the Heat is On, Your Medications May Affect You Differently

You've taken the same pill every morning for months. Then July hits, and suddenly you're lightheaded walking to the mailbox.

Heat can change how some everyday medications affect your body. A prescription that gave you no trouble in January may leave you dizzy, dehydrated or sweating more than usual in August.

Don't stop taking your medications. Instead, learn the warning signs and make a plan before the temperature climbs.

Why Heat and Medications Can be a Risky Mix

Your body cools itself by sweating and sending more blood to your skin. Some prescription and over-the-counter medications can make these processes less effective. 

Other medications may make you less thirsty, change the levels of fluid and electrolytes in your body, or make it more difficult to notice you are getting too hot.
 

“These side effects are not often brought up when you start a new medication, especially when they tend to occur only during times of excessive heat,” said Natalie Howes, PharmD, an Outpatient Pharmacy Manager at HSHS. “That’s why it’s important to talk to your healthcare provider or pharmacist when suddenly experiencing these symptoms.”

Medications that Deserve Extra Attention

You don’t need to memorize drug names. Start by recognizing a few common groups:

Ask an HSHS pharmacist about side effects at an HSHS Community Pharmacy near you.

Why Electrolytes Matter

Electrolytes such as sodium, potassium and magnesium help your muscles, nerves and heart work properly. Sweating and water pills can decrease these minerals, causing dizziness and, in serious cases, an abnormal heartbeat.

“It’s very important to keep your electrolytes in balance so heart medications can work appropriately,” Howes said.

Howes recommends “water first, always” as the first defense against dehydration, but she sees the wisdom of low-sugar sports drinks in some cases.

“When you’re outside in the heat and have been sweating or exercising for a long period of time, I recommend something with electrolytes in it,” she said.

Symptoms You Should Not Shrug Off

Watch for:

• Dry mouth or less urine than normal
• Weakness, unusual tiredness or muscle cramps
• Headache, nausea or confusion
• Dizziness, lightheadedness or fainting
• Heavy sweating or very little sweating in the heat
• Feeling unusually hot
• A racing, pounding or irregular heartbeat

What to do When Symptoms Appear

“The most important thing is to rest, hydrate and get to a cool area with some air conditioning, because we worry about heat exhaustion,” said Howes. “If symptoms like dizziness, headache or fatigue continue, then you should consult or visit a healthcare provider.”

Call 911 for fainting, confusion, loss of consciousness or ongoing heart palpitations.

Despite any concerning side effects, never stop taking a prescribed medication on your own.

“We never want to abruptly stop any medication that is prescribed to us for long-term use, whether it's a blood pressure medication or antidepressant or heart medication,” Howes said.

Keep Medications Out of Heat

Make sure to protect the medications, too. Never leave them in a parked vehicle, trunk or vehicle glove compartment. High temperatures can damage medications and affect how well they work.

“We like to keep shelf-stable medications under about 65° F - 75° F,” Howes said. “If your air-conditioning goes out in your house for a long period of time, or if you keep your tablets or capsules in your car or purse, those are all considerations to take into account.”

Make a Hot-Weather Medication Plan

Create a hot-weather medication plan before any heat advisory.

1. Ask your pharmacist whether any prescription, over-the-counter medicine or supplement you take can affect sweating, thirst, blood pressure, alertness or fluid balance.
2. Find out whether you need to change when you exercise, how often you should drink water, and whether an electrolyte drink is appropriate for you.
3. Keep a medication list on your phone or in your wallet, including doses and the name of your pharmacy.
4. If you begin a new medicine during warm weather, pay attention to how you feel during the first several days.
5. Planning ahead makes it easier to respond before dehydration or overheating becomes an emergency.

Not sure how the heat affects your prescriptions? Your pharmacist can walk you through it - no appointment needed.