by Marianna Rakovitsky, RPh
Oh, Summer! The weather is warm, the sun is shining and it is the time when we try to get outside as much as possible. Summer is my favorite time of the year. I love the beach, days that are filled with light and sunshine, trips to the orchards and hanging out in the backyard. The sunshine that makes the summer such a happy time, improves our mood and fills everything around us with life and energy of course has its darker, dangerous side.
As a source of UVA and UVB radiation the sun may increase the risk of various skin reactions in people on medications. Today I want to talk about medications and sunlight. Many medications that we are taking may increase the risk of photosensitivity or an exaggerated reaction of the skin to the effects of the sun exposure. The photosensitivity reactions are generally divided into two categories: the phototoxic reactions and photoallergic reactions. The phototoxic reactions look like a very bad sunburn and usually you see them on the areas of the skin that are exposed to sunlight. The photoallergic reactions may look like an itchy skin rash and may occur on the areas that were exposed to the sunlight as well on other areas of the body.
UVA rays play a major role in the development of photosensitivity reactions, so to decrease the risk of developing photosensitivity the skin should be protected against both UVA and UVB radiation. At the present time sunscreens are not rated on the level of UVA protection that they may provide. There is a proposal to start a rating system with 4 stars being the highest level of UVA protection. Broad spectrum sunscreens that contain Zinc Oxide and to some extant Titanium Dioxide (may have limited UVA coverage) have both UVA and UVB coverage, they form a physical barrier against UVA and UVB radiation penetrating the skin. Avobenzone is an ingredient that provides reliable UVA coverage and it is available in the sunscreens used in the United States.
Sunscreen is a useful tool when sun exposure is unavoidable, it needs to be applied liberally and reapplied often, have an SPF of at least 15 and it should not give a false sense of security regarding the sun exposure. As always, common sense should prevail. Besides the use of sunscreen the best way to avoid the negative effects of sunlight on the skin, especially in a person who is taking medications that may increase the risk of photosensitivity is to avoid sun exposure in the peak hours between 10 am and 4 pm and wear protective closing such as hats, long sleeve shirts, or sunglasses.
There are quite a few medications that may increase the risk of photosensitivity reactions. Please exercise extra caution when planning to be in the sun while you are taking any of these medications:
Thiazide diuretics – these products may be used as diuretics as well as for blood pressure. They are found in many common combination blood pressure ptoducts:
- hydrochlorothiazide (Microzide),
- bendroflumethiazide (Corzide)
- chlorthalidone (Thalitone)
- indapamide (Lozol)
- metolazone (Zaroxolyn)
Tetracyclines – these antibiotics can be found in eye drops, creams and oinmets as well as tablets and capsules:
- demeclocycline (Declomycin)
- doxycycline (Vibramycin)
- minocycline (Minocin)
- oxytetracycline (Terramycin)
- tetracycline (Achromycin)
Fluoroquinolones – these antibiotics can be found in eye drops, ear drops as well as tablets and capsules:
- ciprofloxacin (Cipro)
- levofloxacin (Levaquin)
- moxifloxacin (Avelox, Vigamox)
- norfloxacin (Noroxin)
- ofloxacin (Floxin)
Phenothiazines – these are antipsychotic medications that may be used for various reasons including nausea and vomiting; promethazine is used in cold and cough products available by prescription:
- chlorpromazine (Thorazine)
- fluphenazine (Prolixin)
- perphenazine (Trilafon)
- prochlorperazine (Compazine)
- thioridazine (Mellaril)
- trifluoperazine (Stelazine)
- promethazine (Phenergan)
- sulfamethoxazole/trimethoprim (Bactrim)
- sulfasalazine (Azulfidine) –Azulfidine is used for inflamatory disease of the lower digestive tract
- sulfisoxazole (Gantrisin)
Vitamin A derivatives – these medications pose a high risk of photosensitivity reactions, it is recommended to apply Tazorac and Retin-A creams at night.
- isotretinoin (Accutane)
- tazarotene (Tazorac)
- tretinoin topical (Renova, Retin-A)
There are other medications including Vitamins B6 and A and supplements such as bitter orange, chlorella, dong quai, gossypol, gotu kola and St. John’s wort. Consider asking your doctor or the pharmacist regarding the potential problems with the sun exposure and the medications that you are taking right now or thinking of taking in the future.
Marianna Rakovitsky is a pharmacist who blogs at the Healthialist Blog.
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