Background: Angiotensin II receptor blockers (ARBs) are widely used to treat hypertension and heart failure. Photosensitivity reactions are cutaneous adverse events due to exposure to a drug and either ultraviolet or visible radiation. Among the ARB class, this type of adverse drug reaction is labeled only for losartan.
Objective: The aim of this study was to provide a descriptive evaluation of photosensitivity reports with ARBs in the World Health Organization Global Individual Case Safety Report database, VigiBase(®).
Methods: All reports of photosensitivity reported with ARBs were identified from VigiBase(®). All variables contained in the reports were analyzed. Information component (IC) and its lower limit of a 95% credibility interval (IC025) values were considered as measures of disproportionality for the assessment of photosensitivity cases reported with ARBs. VigiGrade completeness score (C) was used as a measure of quality of each report. Well-documented reports (C > 0.8) were fully described and analyzed.
Results: Up to December 2014, a total of 203 reports on photosensitivity reported with ARBs and submitted by 25 different countries had been recorded in VigiBase(®). Among them, 25.1% involved losartan, 23.1% involved irbesartan, and 21.7% involved valsartan. In 126 cases, the ARB was the only suspected drug and in 10% of them the reaction was serious. IC and IC025 values indicated a possible positive correlation between photosensitivity and both irbersartan and losartan. A focus on well-documented reports, after excluding those with a co-prescription of other drugs known to cause photosensitivity, showed that out of 18 cases, six were related to losartan, four to olmesartan, three to irbesartan, two to valsartan and to candesartan, and one to telmisartan. Causality assessment was 'probable' in ten cases and 'possible' in eight cases. Moreover, positive dechallenge was reported in ten cases and positive rechallenge in one case.
Conclusions: Photosensitivity reactions have been reported with almost all ARBs in VigiBase(®) with a positive disproportionality for irbesartan and losartan. Considering that ARBs share the same chemical structure, which may have the same response to sunlight, it is plausible to consider photosensitivity as a possible class effect. Physicians and patients should be aware of potentially serious photosensitivity reactions related to treatment with ARBs.