Antibacterial drugs, anti-inflammatory drugs, antidepressants, diuretics, sulfonylurea hypoglycemic drugs, cardiovascular drugs, some contraceptives...

  After taking these medicines, you are most afraid of "seeing the light". Have you done enough sunscreen?

  Autumn is high and fresh, with plenty of sunshine, so it's so pleasant to bask in the sun in such an afternoon.

Today’s special reminder is not about skin care, but if you are taking some drugs, you may be most afraid of "seeing the light". After taking it, you must pay special attention to sun protection to prevent photosensitivity caused by drugs.

So, what is drug-induced photosensitivity?

What kind of drugs can cause photosensitivity in daily life?

Let the pharmacist of Beijing Tiantan Hospital give you a detailed explanation.

When these symptoms occur, watch out for photosensitivity reactions caused by drugs

  Drug-induced photosensitization refers to the adverse reactions caused by exposure to sunlight (mainly ultraviolet light) after taking or topical use of certain drugs.

The photosensitivity reactions include phototoxic reactions and photoallergic reactions.

Phototoxic reactions mainly occur in systemic medications and can occur to anyone. Generally, they can occur within a few minutes to a few hours after exposure to sunlight or similar light sources after the first medication. The disease is mainly concentrated on the exposed skin.

The clinical manifestations are similar to solar dermatitis, which is edematous erythema. In severe cases, blisters appear, and they feel burning and tingling.

The intensity of the reaction is related to the concentration of light-sensitive drugs and the time and intensity of light irradiation.

After removing the photosensitizer and avoiding light, the reaction subsided faster.

  Photoallergic reactions can be induced by topical and systemic medications, and occur in a small number of people with allergies. Small doses of light-sensitive drugs and weak sunlight may cause reactions.

The reaction is not only related to drugs, but also related to genetics and allergies.

The first onset of photoallergic reactions generally has an incubation period of one to two days. In addition to the exposed areas, the rash can also be extended to non-exposed areas.

The clinical manifestations are eczema-like, with erythema, papules, blisters or exudates visible, and generally no pigmentation remains. Chronic damage can cause skin hypertrophy or lichenification, and some may develop chronic and persistent photosensitivity reactions.

These 11 types of commonly used drugs should be sunscreened after taking them

  So, what kind of medicine should you pay special attention to when taking sunscreen to prevent photosensitivity?

In general, it mainly includes some antibacterial drugs, non-steroids, anti-inflammatory drugs, antidepressants and phenothiazine antipsychotics, diuretics, sulfonylurea hypoglycemic drugs, cardiovascular drugs, and antihistamines , Some contraceptives, some anti-tumor drugs, some Chinese medicines, etc.

 Antibacterial drugs

  1. The quinolones are called "floxacin" as a more familiar name.

These drugs are all antibacterial drugs, and their main manifestations are phototoxic reactions.

The photoallergic reaction of quinolones is related to the structure of the drug itself. The order of its effect on causing phototoxicity is: sparfloxacin>lomefloxacin>flerofloxacin>tosufloxacin>ciprofloxacin>enoxa Star>Norfloxacin>Ofloxacin>Levofloxacin.

But for moxifloxacin and gatifloxacin, the two "brothers" have significantly enhanced stability to ultraviolet light, and there is no phototoxicity under treatment conditions.

To put it simply, you must avoid exposure to the sun when taking "floxacin" antibiotics, but we can reduce such adverse reactions by applying it at night.

  2. Tetracyclines Among the tetracycline antibacterial drugs, the drugs that cause photoallergic reactions are chlortetracycline, oxytetracycline, minocycline, metacycline, doxycycline, and demecycline.

The latter two are most prone to photoallergic reactions.

  3. Sulfonamides. These drugs mainly include compound sulfamethoxazole, sulfasalazine, sulfadiazine, p-aminobenzene sulfonamide and sulfa synergist trimethoprim, etc. Dapsone has cross-allergic reactions with such drugs , Can also cause photosensitivity dermatitis.

The clinical manifestations of these drugs are phototoxic reactions.

  4. Antifungal drugs It is currently known that griseofulvin can cause severe phototoxic reactions, cause urine and liver porphyria, and can induce subacute cutaneous lupus erythematosus and aggravate systemic lupus erythematosus.

In addition, there are ketoconazole, flucytosine, itraconazole, voriconazole and so on.

In recent years, there have been reports that terbinafine induces subacute cutaneous lupus erythematosus, and the analysis may be related to the induction of photosensitivity.

  5. Other antibiotics In addition to the drugs mentioned above, chloramphenicol, aminoglycoside drugs (such as streptomycin, kanamycin, gentamicin), anti-tuberculosis drugs (such as pyrazinamide, p-aminosalicylic acid) Sodium), all have been reported to cause phototoxic reactions.

 Non-steroidal anti-inflammatory drugs

  Such drugs that can cause photoallergic reactions include aspirin, diclofenac sodium (voltarin), ibuprofen (fenbid), lornoxicam, phenylbutazone, naproxen, piroxicam, ketoprofen, meloxicam And so on, can be expressed as phototoxicity or photoallergic reaction.

Therefore, patients with cardiovascular disease or who are taking these drugs due to fever or headache should also avoid sun exposure as much as possible.

  Diuretics, such drugs include furosemide (furosemide), spironolactone (spironolactone), triamterene, etc., and the photosensitizing reaction produces a variety of skin damage forms, and the most reported is hydrochlorothiazide (double grams ), can cause phototoxicity, photoallergic, lupus erythematosus-like reactions.

  Cardiovascular drugs, drugs that cause photoallergic reactions include amiodarone, quinidine, nifedipine, nimodipine, captopril, enalapril, indapamide, propranolol, and losartan , Valsartan and so on.

For patients who take amiodarone for a long time, more than half of them can have blue-gray pigmentation in the exposed area.

  Hypoglycemic drugs. Patients with hyperglycemia who are taking sulfonylurea hypoglycemic agents such as glibenclamide, glimepiride, glipizide, and gliclazide should be aware that these drugs can cause photoallergic and lichen planus For changes and pseudoporphyria reactions, you should also pay attention to sun protection.

  Digestive system drugs. Patients who take ranitidine, omeprazole, pantoprazole and other drugs due to gastrointestinal diseases should also be aware that these drugs can also cause photosensitivity.

  Antidepressants and antipsychotics (phenothiazines) These drugs include doxepin hydrochloride, chlorpromazine, perphenazine, estazolam (sulrazepam), etc., which involve phototoxicity and photoallergic reactions , Chlorpromazine can produce blue-gray pigmentation.

  Antihistamines such as chlorpheniramine (chlorpheniramine), cyproheptadine, cromolyn sodium, diphenhydramine, loratadine (carretan), etc., can occasionally cause photoallergic reactions. Patients with rhinitis, allergies, etc. who use these drugs should pay attention!

  Some contraceptives containing estrogen and progesterone oral contraceptives have caused photoallergic reactions in succession. Therefore, you can pay attention to the ingredients when taking these drugs and take reasonable sun protection measures.

  Some of the anti-tumor drugs used by tumor patients, methotrexate and fluorouracil (5-FU) are more sensitive to light, and they are prone to light-sensitive dermatitis after taking them, so you should also pay attention to sun protection.

  Some Chinese medicines are mostly compound preparations, so you can pay more attention to the ingredients of the medicines when using them. According to the data, the Chinese herbal medicines that cause photosensitivity include psoralen, forsythia, bamboo yellow, radix sylvestris, angelica, daikon Bark, Agrimonia, Peucedanum, Parsnip, Nepeta, etc., and Tripterygium wilfordii polyglycosides, but most of them are case reports.

Do not panic about photosensitivity

  During the period of taking the above drugs, try to minimize the time spent in sunlight.

Especially in the summer when the sun is relatively strong, you should hold a sun umbrella, wear a sun hat or sunglasses when you go out, avoid wearing short-sleeved shirts, and apply sunscreen to exposed skin.

In addition, patients can also reduce the incidence of photosensitivity by shortening the medication time, reducing the dose of medication, and applying it at night before going to bed.

For example, if a drug that is only taken once a day is not necessary to be taken in the morning, it can be taken at night.

  If the drug photosensitivity reaction still occurs, don't panic. You can stop the drug, avoid light, and apply the drug rationally. See a doctor if necessary.

The first is to stop the drug and avoid light, give local cold compresses and topical moisturizers; topical glucocorticoid preparations are anti-inflammatory, and antihistamines can relieve itching. In severe cases, oral or intravenous glucocorticoids can be used.

When some drugs must be used for the cause of the disease and exposure to light is unavoidable, it is necessary to strictly avoid the sun and carefully prepare sun protection measures.

  It is worth noting that for some patients, blindly stopping the drug and reducing the dose can also produce adverse reactions or affect the condition.

Therefore, it is particularly reminded: Before stopping the drug or reducing the dose, consult a doctor or pharmacist in time.

  By Chen Xinwei and Zhao Zhigang (Beijing Tiantan Hospital)