This post was written by Anna Koeva, Pharm D, Parkview Health.
As the weather warms up, many of us look forward to spending more time outside. Whether it’s going for a walk, relaxing by the pool or enjoying a backyard gathering, sunshine can be a big mood booster, especially after the long winter months. However, if you take medications, it’s important to know that certain ones can make your skin more sensitive to sunlight or affect how your body handles heat. Understanding these effects can help you stay safe while still enjoying the outdoors.
What is sun sensitivity?
Certain prescriptions and over-the-counter medications can cause what’s called photosensitivity, which means your skin reacts more strongly to sunlight than usual. This can lead to quicker and more severe sunburns, even after a short time outside. You might notice redness, irritation or even a rash in areas exposed to the sun, which can happen even if you normally don’t burn easily.
Medications heat sensitivity
In addition to photosensitivity, certain medications can affect how your body responds to heat. Normally, your body cools itself by sweating when it is overheating. But some medicines can reduce sweating or affect hydration, making it harder to stay cool. This can increase your risk of heat-related illnesses, such as heat exhaustion or heat stroke, especially during hot or humid weather.
Heat exhaustion causes heavy sweating and dizziness, which can be uncomfortable and lead to dehydration. Heat stroke is a life-threatening emergency marked by confusion, unconsciousness and a body temperature over 104°F (40°C). Keep an eye out for any of these symptoms, and be sure to go somewhere shady and cool to help prevent them from happening.
Medications that increase sun sensitivity
Several commonly used medications can make your skin more sensitive to sunlight. Antibiotics such as doxycycline, ciprofloxacin (Cipro®), and sulfamethoxazole/trimethoprim (Bactrim®) are well known for this effect. These are often prescribed to treat infections, but they can increase your risk of burning more easily in the sun. Some acne treatments, including isotretinoin (Accutane®), topical retinoids like tretinoin and benzoyl peroxide, can also make your skin more delicate and prone to sunlight irritation. Even certain over-the-counter pain relievers like ibuprofen and naproxen may increase sun sensitivity in some people, though this is less common.
Additionally, diuretics—sometimes called “water pills”—such as hydrochlorothiazide (often abbreviated as HCTZ) and furosemide (Lasix®) can increase both sun and heat sensitivity and can lead to dehydration, especially in hot weather. Other medications that can cause both photosensitivity and heat sensitivity include tricyclic antidepressants and beta blockers.
Amiodarone (used for heart rhythm control) is a common cause of significant photosensitivity.
Medications that affect heat sensitivity
Some drugs may not affect your skin directly, but instead can make it harder for your body to handle heat. For example, antihistamines like diphenhydramine (Benadryl®) and loratadine (Claritin®), commonly used for allergies, can reduce sweating.
Certain medications used for mental health, such as antidepressants and antipsychotics, may also interfere with your body’s ability to regulate temperature. Ask your doctor or pharmacist about the specific side effects of your mood-regulating medication.
Also, medications used for ADHD, such as amphetamine-based products like Adderall®, can raise body temperature. These stimulant medications may also affect your tolerance to heat.
Tips to stay safe in the sun and heat
These side effects don’t mean that you have to avoid the outdoors altogether. When spending time in the sun, use a sunscreen with SPF 30 or higher. Keep in mind, sunscreen does not work immediately after application. Make sure to apply it at least 30 minutes before sun exposure and reapply every two hours, or more often if you are swimming or sweating. Wearing protective clothing, such as hats and sunglasses, can also help reduce sun exposure. It’s best to seek shade when possible, especially during peak sun hours between 10 a.m. and 4 p.m.
Drink water regularly—even if you don’t feel thirsty. Fluid loss causes electrolyte loss, so be sure to replenish electrolytes, such as salt, with electrolyte fluids or juices, too. Avoid alcohol and caffeine when spending long periods in the heat, as they can contribute to dehydration. Plan outdoor activities for the early morning or evening when it’s cooler. Pay attention to how you feel—symptoms like dizziness, nausea or excessive sweating can be early warning signs of overheating and may lead to heat exhaustion.
When to talk to your healthcare provider
If you notice a severe sunburn, rash or signs of heat illness, it’s important to contact to your primary care provider. You should also ask your provider or pharmacist about sun and heat precautions if you are starting a new medication. They can help you understand your risks and recommend ways to stay safe based on your specific medications and health needs.
The bottom line
Many common medications can increase your sensitivity to the sun or heat, but that doesn’t mean you have to stay indoors all summer. By being aware of these side effects and taking a few simple precautions, you can safely enjoy everything the season has to offer. When in doubt, your pharmacist or healthcare provider is always a great resource to help you use your medications safely and confidently.
