Shedding light on medications that increase sun sensitivity

Have you ever slathered on sunscreen before going outside, and still developed a nasty sunburn—even on a relatively cloudy day? It might have been because you took a medication known to increase sun sensitivity. 

Now that the summer months are upon us, it’s inevitable that we’ll be spending more time outdoors. And if you take any sort of medication, it’s imperative that you do your research to ensure you’re not leaving your skin vulnerable to the sun. Photosensitivity is responsible for nearly 20% of adverse drug reactions in older adults.

How do medications cause photosensitivity?

Certain prescription medications can make your skin more sensitive to ultraviolet light. This chemically-induced change is called photosensitivity. Photosensitivity can result in sunburn, a rash, blisters, and other symptoms caused by an allergic reaction of the skin. There are two types of photosensitivity reactions, photoallergy and phototoxicity, both of which can happen from exposure to the sun or UV radiation from artificial light.

So why do these particular medicines wreak havoc on our skin when it’s exposed to sunlight? “These medications are photosensitizers,” explains Noelani Gonzalez, MD, a board-certified dermatologist at Mount Sinai Hospital in New York City. “So when the sun hits you, and you have either been ingesting or applying these medications, they release free radicals, and they cause an exaggerated sunburn reaction.”

Of the two types of sun sensitivity, Dr. Gonzalez says the more relevant concern is phototoxicity, a condition where the skin becomes sensitive to sunlight after taking certain drugs (either orally or topically). Phototoxicity can occur within hours after sun exposure on the areas of skin that were exposed to UV rays.  

Photoallergy occurs when UV rays cause the shape of a molecule to transform into a new substance, resulting in the immune system attacking the foreign presence, and typically develops 24-72 hours after sun exposure. Photoallergic reactions are “far less common,” says Dr. Gonzalez, mainly because the patient needs to have been previously exposed to the medication in question.  

Symptoms of photosensitivity

Symptoms of chemical photosensitivity vary based on their cause. Photoallergic reactions often result in blisters, redness, a rash, and oozing areas of skin that lasts for up to two weeks. Indicators of a phototoxic reaction can vary from symptoms like skin irritation and pain to localized swelling. But Dr. Gonzalez says the one thing you should watch out for is “a very exaggerated sunburn,” and one that comes on more quickly than a typical sunburn. If you find yourself getting red after a short time in the sun, seek cover. You could end up with additional symptoms such as blisters and itchiness if you stay out in the sun unprotected. 

RELATED: What is a sun allergy?

What medications cause sun sensitivity?

The best place to start is by asking your doctor or pharmacist for information about your medications and sun sensitivity. 

A few of “the biggest offenders” are certain antibiotics used to treat common ailments like sinus infections and urinary tract infections, according to Erika Prouty, Pharm.D., a pharmacist at Stop and Shop in West Springfield, Massachusetts. They include Cipro, Levaquin, Bactrim, and Cleocin. Other antibiotics, like amoxicillin, have no known effect on sun sensitivity.

The spectrum of medications that could lead to a burn ranges from over-the-counter drugs like Aleve, Advil, and Motrin (NSAIDs, specifically) to antidepressants, diuretics, and diabetes and high blood pressure medicines.  

All of the following medications can cause photosensitivity when you’re in the sun, according to the U.S. Food and Drug Administration (FDA) and The Skin Cancer Foundation:

• Antibiotics (ciprofloxacin, doxycycline, levofloxacin, tetracycline, trimethoprim)
• Acne treatments (including acitretin, isotretinoin, tazarotene, and tretinoin)
• Antifungals (flucytosine, griseofulvin, voriconazole)
• Allergy medications (cetirizine, diphenhydramine, loratadine, promethazine, cyproheptadine)
• Cholesterol lowering statin drugs (simvastatin, atorvastatin, lovastatin, pravastatin)
• Diuretics (thiazide diuretics commonly used for high blood pressure: hydrochlorothiazide, chlorthalidone; other diuretics: furosemide and triamterene)
• Non-steroidal anti-inflammatory drugs (ibuprofen, naproxen, celecoxib, piroxicam, ketoprofen)
• Oral contraceptives and estrogens
• Phenothiazines (tranquilizers, antiemetics: examples, chlorpromazine, fluphenazine, promethazine, thioridazine, prochlorperazine)
• Psoralens (methoxsalen, trioxsalen)
• Retinoids (acitretin, isotretinoin)
• Sulfonamides (acetazolamide, sulfadiazine, sulfamethizole, sulfamethoxazole, sulfapyridine, sulfasalazine, sulfisoxazole)
• Sulfonylureas for Type 2 diabetes (glipizide, glyburide)
• Alpha-hydroxy acids in cosmetics
• Tricyclic antidepressants including amitriptyline, amoxapine, desipramine, doxepin, imipramine, nortriptyline, protriptyline, and trimipramine
• St. John’s wort

“There are a lot of commonly prescribed drugs that a large number of the population are on, and they’re not always talked about for their sun sensitivity,” Dr. Prouty says. “Like medications used for cholesterol, such as Lipitor and Crestor, and even [prescribed] pain medications like oxycodone.” 

Diagnosis and treatment

Diagnosis of a photosensitivity reaction usually involves an evaluation by a healthcare provider. He or she will review your medical history, symptoms, current medications, skin creams, and cosmetics. This will help your healthcare provider confirm if your symptoms were caused by a photoallergic or phototoxic reaction. 

In some cases, diagnostic testing such as phototesting (to measure the skin’s reaction to UV rays while taking a specific drug), photo patch testing (to measure the reaction of the skin to UV light after a chemical is applied to the skin) and clinical rechallenge (starting the drug that was suspected to cause the reaction and observing its effect) may be performed. 

If you do experience a photosensitivity reaction, treat it the same way you would a sunburn by following these steps.

• Get out of the sun
• Cool off the area of sun exposure by dipping in cool water and/or using a cool compress. Do not place ice on your skin.
• Moisturize your skin after bathing while it’s still damp, to reduce damage.
• Take over-the-counter NSAIDs such as naproxen, ibuprofen, or aspirin to decrease inflammation.
• Drink plenty of water and sports drinks to stay hydrated (burns draw extra fluid to the skin to help repair skin damage).

If you have fever or chills or are experiencing blisters or pus or red streaks at the site, see a doctor for medical advice as these are all signs of infection and may need antibiotics.

Of course, the best way to lower the risk of photosensitivity and prevent these side effects is with proper sun protection. Cover up with protective clothing like long sleeves and a wide-brimmed hat. Avoid outdoor activities between 10 a.m. and 4 p.m. Generously apply (and frequently reapply!) a broad-spectrum sunscreen (SPF) to your exposed skin.

If you have had sun sensitivity in the past, ask your healthcare provider about medication alternatives.