DOH says leaflet on drug containing Allopurinol should print relevant notes on pharmacogenomics


Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) is an extremely serious and life-threatening epidermal adverse reaction. In the event of occurrence of SJS/TEN death of a healthy person or serious injury could happen. Therefore, the DOH has all along paid serious attention to such incidents. Information of drug hazard in past years show that, out of 103 cases of drug hazard applications for suspected use of allopurinol drug, 62 cases obtained relief for use of SJS/TEN drugs after examination. Upon inspection, the DOH has approved 63 permits for drugs containing allopurinol. The indications are: gout, uric acid stone, cancer or high uric acid blood syndrome generated by chemical treatment.

Based on retracing research on allopurinol and SJS/TEN drug hazard, after careful evaluation, the DOH issued the Wei-Shu-Yao-Zi No. 0980361467 announcement that relevant HLA-B* 5801 notes should be printed on allopurinol drug leaflet. The added content should comprise of “we know from retracing research reports that serious epidermal reactions from use of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) has significant statistical correlation with Human Leukocyte Antigen (HLA-B*5801) genes. Stevens-Johnson Syndrome has comparatively higher occurrence rate (rare but not extremely rare) in certain Asian nations (such as Taiwan, Malaysia and the Philippines). The prevalence of HLA-B*5801 genes among the Taiwan genetic group is comparatively higher than the European and Japanese genetic groups. Before using allopurinol treatment, it is necessary to consider testing for possession of HLA-B*5801 genes. For patients who have no adverse reactions after prolonged use of allopurinol treatment, it is not recommended for gene screening. Regardless of possession of HLA-B*5801 genes or not, the risk of Stevens-Johnson Syndrome is greatest in the couple of months after commencement of treatment. Gene screening cannot replace appropriate clinical safety monitoring and patient treatment. Many patients with HLA-B*5801 genes did not have SJS/TEN side effect under allopurinol treatment. For instance, among the 135 patients who were being treated with allopurinol for 6 months without discovering any SJS/TEN or epidermal sensitive side effects, approximately 15% of them have HLA-B*5801 genes while patients who do not have HLA-B*5801 genes could also have SJS/TEN side effects. This reminds citizens that it is necessary to closely monitor the occurrence of adverse reactions from use of allopurinol drugs.

The DOH has closely monitored the safety information of such drugs at home and abroad. At the same time, it also appeals to physicians to carefully evaluate the risk and benefits of drug use in prescribing such drugs for patients, and closely monitor the patients after using such drug. The DOH has established an automatic drug safety monitoring mechanism. Aside from the drug adverse reaction information system, the DOH tries to understand at all time relevant safety information to ensure drug use safety for the public. The DOH also reminds the medical personnel or patients to immediately notify the national drug adverse reactions reporting centers established by the DOH if suspected of adverse reactions after use (or taking) of drugs. Please dial the direct line at 02-2396-0100 or visit the website: http://adr.doh.gov.tw