Q: I’m going to be travelling down south and I’m prone to getting cold sores in the heat. I know pharmacists can prescribe medication if you have a cold sore, but can they also prescribe medication to have on hand in case one develops?
Yes. In fact, having treatment available in advance can be helpful not only when travelling but for anyone who regularly gets cold sores, because cold sore medications work best when started at the first sign of an outbreak.
In New Brunswick, pharmacists can assess and prescribe for cold sores for patients who are at least 12 years of age and who have previously been diagnosed with cold sores by a physician or nurse practitioner. With a valid New Brunswick Medicare card, one assessment is publicly funded per 12-month period, but the pharmacist can prescribe up to six treatment courses during that assessment to be used over the following year.
Cold sores are caused by the herpes simplex virus, most commonly HSV-1. The initial infection occurs through direct contact with the virus, often through kissing or contact with infected saliva. Many people are first exposed during childhood and may not even realize they have been infected. Once acquired, the virus remains dormant in nerve cells and can reactivate from time to time, causing recurring cold sores.
Common triggers include illness, stress, fatigue and sun exposure. Since sun exposure tends to trigger your outbreaks, you may find using a lip balm with sunscreen and protecting your face from prolonged sun exposure helps reduce their frequency.
Cold sores often start with tingling, itching, burning or tenderness before a blister appears. This early warning period is called the prodromal stage, and it is the best time to begin treatment. Small fluid-filled blisters may then develop, eventually breaking open, crusting over and healing. Without treatment, most cold sores heal on their own within one to two weeks.
The most common oral antiviral medication I prescribe during assessments is valacyclovir, also known as Valtrex. For cold sores, it is taken as two doses 12 hours apart, making it a short and convenient treatment. Typical side effects such as mild headache and upset stomach are generally avoided or minimal because treatment is so short. Other oral antiviral options include acyclovir and famciclovir. There is no permanent cure for cold sores as antivirals cannot eliminate the virus from the body, but they can help shorten an outbreak when started promptly.
In clinical studies of valacyclovir, most patients began treatment within two hours of noticing their first symptoms. Starting treatment early may prevent some cold sores from progressing to blisters, although this benefit has not been conclusively demonstrated. If a cold sore does develop, treatment can shorten the outbreak by approximately one day, accelerate healing and reduce the duration of pain and discomfort. However, once a blister or ulcer has developed, starting valacyclovir may not be as effective.
Topical treatments can be another option but are generally less effective as they must be applied multiple times a day. The one I typically prescribe is Xerese, which combines acyclovir, an antiviral, with hydrocortisone, a mild corticosteroid that helps reduce inflammation. In a large clinical trial, 42 per cent of patients using Xerese did not progress to an ulcerative cold sore, compared with 35 per cent using acyclovir alone (also known as Zovirax) and 26 per cent using a placebo cream. Xerese is applied five time daily for five days and should also be started at the first sign of an outbreak. Gently dab the cream to the affected area rather than rubbing the cold sore, as rubbing may spread the infection to other areas around the mouth. For a self-treatment option, docosanol (Abreva) can be purchased over the counter and may be useful for those with mild or infrequent lesions.
Cold sores are contagious, especially when a blister or sore is present. Avoid kissing and sharing drinks, utensils or lip products during an outbreak. Try not to touch the affected area, and wash your hands if you do, particularly before touching your eyes. Although cold sores are most contagious when blisters are present, the virus can sometimes spread even when there is no visible sore.
Finally, not every sore around the mouth is a cold sore. If a lesion looks different from your usual outbreaks, is unusually severe, involves the eye area or does not heal as expected, seek further medical assessment.