Are you looking forward to spending some time outside during the summer? Maybe you have a beach vacation planned, or perhaps you will be doing some walking outdoors. If you are a runner, a golfer or a tennis player, you will likely be soaking up some rays even after applying sunscreen. Is your medicine making you more susceptible to sunburn or skin cancer? A surprising number of common medications can increase sun sensitivity. It’s not the sort of side effect prescribers are likely to mention.
Why Do So Many People Love the Sun?
Most people love the sun. For one thing, it feels good. Of course a sunburn hurts and does damage to the skin. But people who wear highly effective sunscreens and spend time in the sun often enjoy the feeling.
Dermatologist Steven Feldman, MD, PhD, and colleagues caught a fair amount of heat because of a pilot study demonstrating that ultraviolet (UV) exposure from tanning beds “…may have some potential in reducing pain in persons with FMS [fibromyalgia syndrome] (Journal of Alternative and Complementary Medicine, Jan. 1, 2009).
Dr. Feldman and his colleagues go on to say:
“Ultraviolet light, either alone or combined with chemicals, has been used for decades as an effective treatment of skin disorders; it has powerful immunomodulatory effects on skin and is a primary treatment for certain inflammatory skin diseases, particularly psoriasis.”
They also note that UV exposure releases neuropeptides in the central nervous system:
“In support of a central effect, we have previously observed that there is a UV-specific relaxation effect of tanning bed exposure in frequent tanners.”
“Greater improvements in mood with UV compared to non-UV (control) treatment further supported the apparent subjective beneficial effect of UV.”
In an earlier study, Dr. Feldman and his co-authors revealed that ultraviolet exposure had a “relaxing” effect on subjects (Journal of the American Academy of Dermatology, July, 2004).
News Corp Australia, May 19, 2014 described this earlier research:
“In another study frequent tanners chose a tanning bed that gave them UV light over one that had been modified to block the UV.
“Both beds looked and felt identical, but the tanners said the UV one was more relaxing.
“’That was fairly definitive proof that the UV has an effect that people can feel and it drives their behaviour.’”
“Professor Feldman says his findings are backed by other researchers who have found that UV light stimulates pleasure sensors in the brain associated with other addictions.”
Not surprisingly, other dermatologists were not pleased to learn that ultraviolet exposure might produce benefits. Everyone agrees that UV light damages the skin. But it also explains why people often spend time in the sun even though they know it can cause premature aging, wrinkling, a leathery look and skin cancer!
Vitamin D and Sun Exposure:
Scientific evidence shows that our skin makes vitamin D after sun exposure. This hormone, in turn, can help enhance immunity. “Sunshine deficiency” has been linked to a number of cancers, as well as diseases such as type 1 diabetes, multiple sclerosis and asthma. During the winter, some people experience seasonal affective disorder (SAD). Symptoms include depression, irritability and weight gain.
A study from Finland has revealed that people who live in sunnier neighborhoods get a boost in brain power. The investigators studied over 1,800 middle-aged Finnish people. Daily sun exposure was calculated over several years. Those individuals with the greatest residential exposure to sunlight for the longest periods of time did better on memory tests (Scientific Reports, Dec. 2, 2022).
Why Dermatologists Shun the Sun!
Skin specialists know that ultraviolet radiation damages our delicate epidermis. Too much exposure to ultraviolet radiation leads to an increased risk of skin cancers. That includes basal cell and squamous cell carcinomas.
More worrisome is melanoma! This is a much more aggressive and lethal type of skin cancer. There are data that link a history of sunburn to melanoma (American Journal of Epidemiology, May 1, 2016).
The bottom line is that we should absolutely avoid sunburn! We should protect our skin from damaging ultraviolet radiation. That means applying effective sunscreens. We should also wear hats and other protective gear whenever we step outside in the middle of the day. Dermatologists know this, but their medical colleagues may not realize that a surprisingly large number of frequently prescribed medications can make the skin far more vulnerable to sun damage.
Which Medicines Boost Sun Sensitivity?
Blood Pressure Pills:
Hydrochlorothiazide and Sun Sensitivity:
One of the most popular drugs in the pharmacy is hydrochlorothiazide (HCT aka HCTZ). Doctors often prescribe this diuretic to treat hypertension. At last count, 17 million Americans were taking this medicine to control their blood pressure.
Although it is generally considered a very safe medicine with few side effects, HCTZ increases the risk of skin cancer. A systematic review and meta-analysis concluded that HCT is associated with an increased risk of squamous cell carcinoma and melanoma (BMC Medicine, July 7, 2022).
One reader wrote:
“I recently stopped taking HCTZ with my doctor’s approval. I had taken it since 2006 and have had both squamous and basal cell carcinomas since then….and NOT just one or two spots! In fact, my dermatologist at the time stated in my records that he wondered why I had so many! I have been treated with freezing, Mohs surgery, blue light therapy and fluorouracil cream. Despite that, I still have precancers and was just diagnosed with melanoma in situ.”
You may not even realize you are taking hydrochlorothiazide. That’s because it is often included in other blood pressure medications. Here is just a sample of the medications that also have HCT/HCTZ as an additional ingredient:
Hydrochlorothiazide is found in:
- Aliskiren + HCT (Tekturna HCT)
- Amlodipine + HCT (Exforge HCT
- Benazepril +HCT (Lotensin HCT)
- Bisoprolol + HCT (Ziac)
- Fosinopril + HCT (Monopril HCT)
- Hydralazine + HCT + Reserpine (Ser-Ap-Es)
- Hydralazine + HCT + Reserpine (Unipres)
- Hydrochlorothiazide (Hydrodiuril)
- Labetalol + HCT (Trandate HCT)
- Lisinopril + HCT (Zestoretic)
- Losartan + HCT (Hyzaar)
- Metoprolol + HCT (Lopressor HCT)
- Metoprolol + HCTZ (Dutoprol)
- Olmesartan + HCTZ (Benicar HCT)
- Propranolol + HCT) (Inderide)
- Quinapril + HCT (Accuretic)
- Telmisartan + HCT (Micardis HCT)
- Triamterene + HCT (Dyazide, Maxzide)
- Valsartan + HCTZ (Diovan HCT)
HCT, Sun Sensitivity and Lip Cancer:
A study suggests that hydrochlorothiazide as well as other antihypertensive medications (lisinopril and nifedipine) may increase the risk of lip cancer (Archives of Internal Medicine, Sept. 10, 2012). This is no doubt related to the increased sun sensitivity these drugs produce.
The authors of this article note:
“Thiazide diuretics, triamterene, some ACE inhibitors and lisinopril are photosensitizing drugs. Photosensitizing drugs are believed to absorb energy from ultraviolet and/or visible light causing release of electrons. This leads to the generation of reactive oxygen intermediates and free radicals which damage DNA and other components of skin cells and produce an inflammatory response. The causation of squamous cell skin cancer by the treatment of psoriasis with repeated exposures to photosensitizing psoralen and ultraviolet radiation (PUVA) and the association of HCTZ and other antihypertensive drugs with risk of squamous cell skin cancer both support the biological plausibility of an increased risk of lip cancer due to photosensitizing antihypertensive drugs.”
Photosensitizing drugs absorb ultraviolet energy and increase the likelihood of cellular damage. Previous research has shown that such medications may predispose people to squamous cell skin cancer. People taking diuretics like hydrochlorothiazide should be especially careful to protect their skin and lips from ultraviolet sun exposure.
A Study from Down Under About HCTZ and Sun Sensitivity:
The Australians are especially concerned about sun exposure and skin cancer. Researchers conducted a study of veterans in New South Wales, Australia (Basic & Clinical Pharmacology & Toxicology, Oct. 2020). They were looking for a connection between exposure to hydrochlorothiazide and lip cancer and malignant melanoma.
“In this population-based study nested within Australia’s most populous state, we found elevated risks of both lip cancer and malignant melanoma associated with HCTZ use. Our findings are in line with those reported from Denmark, the UK, and the United States, and further support the existence of an association between HCTZ use and increased risks of skin cancer. This association is particularly relevant in Australia, as it is home to the highest incidence of skin cancer in the world and the use of HCTZ is widespread.”
Lasix (Furosemide) and Sun Sensitivity:
Another popular diuretic, furosemide (Lasix), may also be linked to an increased risk of skin cancer (Journal of Investigative Dermatology, Aug., 2013).
If you would like to better understand the risks of skin cancer linked to popular diuretics, here is a link you will not want to miss. You will also want to share both articles with friends or family members who may be taking blood pressure medications that contain HCT:
Tetracycline and Sun Sensitivity:
Research from New Hampshire confirms this link, as well as an increased risk of basal cell carcinoma, a different type of skin cancer, for people taking the antibiotics tetracycline or doxycycline. The risk is highest for people who tend to burn rather than tan when exposed to sunshine (Archives of Internal Medicine, online, Aug., 2012; Journal of Investigative Dermatology, August 2013; Gomez-Bernal et al, Actas Dermo-sifilograficas, May 2014).
We worry far less about tetracycline than HCT because most people only take an antibiotic for a week or two. It is unlikely that the sun sensitivity problem would cause trouble in such a short period of time. One exception would be the long-term treatment of acne. Teenagers and some adults are put on tetracycline for months or years. In such cases, they should practice prudent protection against the sun.
Ketoprofen and Sun Sensitivity:
Doctors prescribe the NSAID ketoprofen to relieve the pain of arthritis, bursitis and similar problems. Some people taking this nonsteroidal anti-inflammatory drug develop a rash on sun-exposed skin (Loh & Cohen, Indian Journal of Medical Research, Dec. 2016). Octocrylene, found in some sunscreens, may make this rash worse.
Report from A Reader re: Sun Sensitivity:
Jean shares this experience with HCTZ:
“Well, well. I have been ingesting HTCZ for probably 20 years. About 6 yrs ago I was diagnosed with basal cell cancer on the end of my nose. I had to have surgery, of course. Not a pretty site but the work was done in a doctor’s office and I went home loaded with bandages on my face and of course, discomfort.
“I was told my problem was most likely from my teen years and onward into the sun through later years. Maybe it developed from my love of sunbathing plus the HTCZ medication I still take even though my blood pressure seems to be pretty good in these later years.
“My husband is down at the pool sunning, swimming and reading and visiting at this very moment. After my experience I have lost my umph for this great relaxing way to spend some time. Never thought of this darn HCTZ being a culprit.
“We both love you Graedons and have been faithful listeners to your Public Radio shows (for years now) and thank you so much for the way you help us all take care of ourselves, when possible. Keep up the good work. We need you.”
Thank you, Jean. We keep going because of people like you. Please encourage family, friends and colleagues to subscribe to our free newsletter at this link. While you are there you may want to consider subscribing to our ad-free option. You can read all our articles without distractions by subscribing to the $5/month ad-free browsing option at this link.