Kava hepatotoxicity: comparative study of two structured quantitative methods for causality assessment.
OBJECTIVE
Ingestion of the medicinal herb kava has been associated with hepatotoxicity. We aimed to compare two different quantitative methods of causality assessment of patients with assumed hepatotoxicity by the herb.


METHODS
We assessed causality in 26 patients from Germany and Switzerland, using two structured quantitative analytical methods: the system of Maria and Victorino (MV) and that of the Council for International Organizations of Medical Sciences (CIOMS). In all 26 patients, regulatory ad hoc evaluation had suggested a causal relationship between liver disease and kava use.


CONCLUSIONS
Assessment with the MV scale resulted in no or low graded causality for kava in the 26 patients with liver disease. Causality was probable (n=1), possible (n=2), unlikely (n=7), and excluded (n=16). Causality for kava was more evident with the CIOMS scale: highly probable (n=1), probable (n=2), possible (n=6), unlikely (n=2) and excluded (n=15). However, the results of both quantitative causality assessments are not supportive for most of the regulatory ad hoc causality assessments of the 26 patients.


CONCLUSIONS
Grades of causality for suspected hepatotoxicity by kava were much lower when evaluated by structured quantitative causality assessment scales than by regulatory ad hoc judgements. The quantitative CIOMS scale is the preferable tool for causality assessment of spontaneous reports of hepatotoxcity involving kava.
Teschke
R
R
Department of Internal Medicine II, Division of Gastroenterology and Hepatology, Klinikum Hanau, Teaching Hospital of the Johann Wolfgang Goethe-University Frankfurt/Main, Hanau, Germany. rolf.teschke@gmx.de
Fuchs
J
J
Bahre
R
R
Genthner
A
A
Wolff
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001699:Biometry; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology*; D004359:Drug Therapy, Combination / Q000009:adverse effects; D005260:Female; D006801:Humans; D020901:Kava / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D004366:Nonprescription Drugs; D008517:Phytotherapy / Q000009:adverse effects*; D013997:Time Factors
D004366:Nonprescription Drugs