Digoxin-like immunoreactivity in Chinese medicine.
Immunoreactive digoxin-like activity was observed in Chinese medicine, KYUSHIN tablet, taken popularly in Japan without prescription. The antibodies used in the assays of digoxin reacted with Chan-su, the major effective component of KYUSHIN, which contained cardiotonic steroids with similar chemical structure as digoxin. One tablet of KYUSHIN had digoxin-like immunoreactivity equivalent to 1.9, 1.5, and 72 micrograms of digoxin measured by three different commercial kits. These different equivalences may be attributed to differences in cross-reactivity of the antibody used in the immunoassays. Two healthy volunteers took two KYUSHIN tablets three times a day, a typical dose, and digoxin-like immunoreactivity reached almost 0.4 micrograms/L in 0.5 day. Therapeutic drug monitoring should be interpreted carefully in patients taking Chinese medicines, many of which contain the Chan-su component.
Fushimi
R
R
Central Laboratory for Clinical Investigation, Osaka University Hospital, Japan.
Koh
T
T
Iyama
S
S
Yasuhara
M
M
Tachi
J
J
Kohda
K
K
Amino
N
N
Miyai
K
K
D003429:Cross Reactions; D004077:Digoxin / Q000032:analysis / Q000097:blood*; D004339:Drug Compounding; D006801:Humans; D008516:Medicine, Chinese Traditional; D013997:Time Factors
D004077:Digoxin