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Sun, heat and medicine

Updated 25 July 2012

Various medicines can make your skin more sensitive to sunlight (photosensitivity), and it concerns both medicines in tablet form and other forms, such as creams.

You should therefore protect yourself from the sun by wearing clothes, a hat or by using a good sunscreen if you take medicine that makes your skin more sensitive to light.

Please also see our general advice on sun protection.

Medicine makes your skin more sensitive to the sun

When you stay in the sun, you should be extra careful if you regularly take

  • cardiovascular medicines, such as diuretics and blood pressure medicine
  • medicines for the treatment of psychiatric disorders (antipsychotics)
  • medicines for the treatment of infections (antibiotics)
  • medicines against malaria
  • natural remedies, such as St. John's Wort against depression, dejection or sadness.

Other types of medicines may also increase your skin's sensitivity to light.

Symptoms of photosensitivity

The most common symptoms of photosensitivity are:

  • redness
  • swelling
  • blisters
  • rash

Medicines that may increase the risk of heat strokes

Certain other medicines may increase the risk of heat strokes if you stay in the sun. This is the case for medicines such as antipsychotics.

Heat and dehydration can influence how your medicine works

If you stay in a very hot environment or if you are dehydrated, this may impact the medicine that you are taking, either by reducing or increasing its effect, which could cause you to have side effects or result in a possible overdose.

Protect yourself against the sun and keep taking your medicine

You should keep taking your medicine even if you experience the symptoms of photosensitivity.

Instead, you should:

  • stay in the shade as much as possible
  • stay out of the sun around noon
  • cover your body with clothes or use a sunscreen with a high protection factor and an efficient UVA filter.

Read about side effects in the package leaflet

It is always a good idea to read the package leaflet that comes with your medicine. You can also download the package leaflet in Danish at the website indlaegsseddel.dk.

The package leaflet informs you of possible side effects, including whether the medicine can make your skin more sensitive to light. If you are unsure, ask your doctor or pharmacy for advice.

Keep your medicine at temperatures below 25°C

Just as you should protect yourself from the sun, you also need to take care of your medicine. In general, medicine should be stored and transported at temperatures below 25°C.

Some medicines must even be kept in the refrigerator. The package leaflet will tell you if your medicine should be stored in a special way.

If you keep your medicine at too high temperatures, it may have an impact on the medicine's effect. Therefore, it is particularly important that you pay attention to how you store medicine that you need instantly. This is the case for medicines such as:

  • antibiotics
  • insulin
  • painkillers and sedatives
  • medicines against colds (nasal spray)
  • asthma medicine.