THE QUESTION: If I'm taking medication for blood pressure or an irregular heart beat, do I need to be careful with sun exposure?"
THE ANSWER: There are a number of medications, both prescription and over-the-counter, that can increase your skin's sensitivity to the sun. Most often, this means that your skin will burn more easily and with less sun exposure than it would if you were not taking the medication. In other more rare cases, you may even develop a sun allergy - the reaction produced by your skin involves the immune system and you may develop an allergic response such as a rash or hives. This reaction may start out only on sun-exposed skin, but may spread to other unexposed areas and often is only seen 24 to 48 hours after exposure.
Heart and blood pressure medications are very important for lowering your risk of heart attack and stroke as well as to maintain a healthy heart and circulatory system. Generally, the benefits of these medications far outweigh the risks. However, there are a few medications in this family that do increase sun-sensitivity, even in individuals with darker skin.
Blood-pressure medications that are often referred to as "water pills", such as hydrochlorothiazide and furosemide (also known by the brand name of Lasix), can make your skin more likely to experience sun sensitivity. Nifedipine and amlodipine (also known as Adalat and Norvasc) are examples of medications called "calcium channel blockers" that have also been associated with this reaction. In addition, "ACE inhibitors" - which include ramipril (Altace), enalapril (Vasotec) and captopril (Capoten)- may put you at increased risk as well. Although not a blood-pressure medication, amiodarone, (Cordarone) which is used to control heart rate and rhythm, has been linked to increased sun sensitivity and rash. The risk of these reactions increases with higher doses and with greater sun exposure.
The good news is that many of these medication-related reactions are preventable. The best way to protect yourself is to minimize the exposure of your skin to direct sunlight and ensure that you are using a sunscreen that is active against ultraviolet A rays. Sunscreen ingredients such as avobenzone (Parsol 1789), titanium dioxide and zinc oxide screen out UVA rays.
The Canadian Dermatology Association generally recommends using a broad spectrum sunscreen with a minimum SPF of 30 applied liberally at least 20 to 30 minutes before sun exposure. SPF refers to the ability of the sunscreen to protect against UVB rays so check the label to be sure that your sunscreen also protects against UVA rays. This is important not only for those of you heading south this time of year to escape the snow and cold, but also for those who are staying home and enjoying outdoor winter activities since any exposed skin is susceptible to the damaging effects of the sun and snow reflects up to 80 per cent of the sun's rays.
If you are unsure about the effects of your medications on your skin's sun sensitivity, be sure to ask your pharmacist or doctor.
Kori Leblanc is a pharmacist and clinical practice leader in the pharmacy department and Peter Munk Cardiac Centre at the University Health Network in Toronto.