Purpose: To study the frequency and degree of adverse effect, other than liver dysfunction, of isoniazid (INH) preventive therapy in Japanese people.
Object and method: Chart review of Japanese persons who started isoniazid preventive chemotherapy in the two clinics in Tokyo, from 2003/1/1 to 2004/12/31.
Result: There were 779 cases who did not transiently or completely stop INH preventive therapy because of adverse effect, and 20 cases who stopped INH transiently or completely because of adverse effect other than liver damage (total 799 cases). Of those cases, 153 cases (153/799=19.1%) experienced one or more adverse effect other than liver damage, and 20 cases (20/799=2.5%) of these 153 cases stopped INH transiently (12 cases) or completely (8 cases). For each category of adverse effect, digestive system symptoms were most frequent (5.9%), and then in frequency order, lethargy or easy-fatigability (4.6%), central nervous symptoms (4.5%), skin eruptions (2.6%), acne (2.5%), alcohol intolerance-like symptoms (2.5%), peripheral neuropathy (0.4%), arthralgia or limb pain (0.3%). Adverse effect requiring stopping INH transiently or completely were skin eruption (1.3%), digestive system symptoms (1.1%), central nervous symptoms (0.6%), acne (0.1%). Most of the adverse effect were not serious, and not required hospitalization. In isoniazid (INH) preventive therapy in Japanese people, adverse effect other than liver damage were not infrequent, but most of them are not serious, and do not disturb continuation of preventive therapy in most cases.