For superficial or small IH, in which systemic therapy may not be indicated, topical β-blockers, specifically timolol gel forming solution (GFS), have proven to be a useful alternative. In a recent multicenter retrospective study looking at the efficacy of timolol 0.5%-0.1% GFS applied twice daily for superficial IH, 72 of 73 patients exhibited some improvement, the mean duration of therapy was 3.4 months and treatment was well tolerated. However, some caution must be exercised with the use of topical timolol due to its increased potency of between 4 and 10 times greater than propranolol, as well, topical absorption would bypass first-pass metabolism in the liver. To date, a small amount of topical timolol (e.g., 1 drop applied twice a day to intact skin overlying a hemangioma) appears to be safe, but the exact level of systemic absorption is not yet known. Thus, a conservative and cautious approach should be practiced in administering topical timolol while awaiting further information about potential side effects.
Skin Therapy Letter. 2013;18(6) © 2013 SkinCareGuide.com