Some medicines can make skin sun-sensitive, says NPS MedicineWise clinical adviser

Jan 9 2015

Some medicines can make your skin more sensitive to the sun and this summer season NPS MedicineWise advises Australians to check their medicines packaging for warnings to avoid excessive skin exposure to sunlight and sunlamps.

Clinical adviser at NPS MedicineWise, Dr Andrew Boyden says many people may have seen a label on their medicine packaging instructing them to avoid excessive skin exposure to sunlight and sunlamps whilst taking it.

“This is because many medicines can make skin sun-sensitive, even after only brief exposure to the sun. This is called photosensitivity and means that if you expose your skin to the sun while using one of these medicines, you could have an adverse skin reaction.”

“A phototoxic reaction often looks like a severe sunburn with skin redness, swelling and blistering on the sun-exposed areas and will usually develop 5 to 20 hours after exposure. The other reaction that people are at risk of is called a photoallergic reaction and that can cause an itchy, dry, bumpy or blistering rash which can also spread beyond sun-exposed areas. This kind of rash develops at around 24 to 48 hours after sun exposure.”

Medicines that can cause phototoxic or photoallergic skin reactions include:

• Acne and psoriasis medicines (oral and topical)
• Some antibiotics
• Non-steroidal anti-inflammatory medicines (NSAIDs) (oral and topical)
• Some antihistamines
• Some anti-nausea medicines
• Some chemotherapy medicines
• Some medicines for diabetes
• Diuretics
• Medicines to regulate heart rhythm
• Some antipsychotic medicines
• Some antidepressants
• St John’s wort

Some medicines can cause changes in skin colour during sun exposure. For example, exposure to sunlight whilst taking amiodarone (a medicine to treat heart rhythm disturbances) can cause blue-grey discolouration of the skin over time.

“This photosensitivity risk doesn’t mean you have to stay indoors and avoid summer holiday activities,” says Dr Boyden. “But if the medicine’s label, its enclosed consumer medicine information leaflet (CMI), your doctor or pharmacist says that you should avoid sunlight when taking a particular medicine, be particularly mindful of limiting your exposure. You can help protect yourself by using sunscreen, wearing protective clothing and a hat, and avoiding going out in peak UV times of the day as much as possible.”