This antibiotic is a potent inhibitor of organic anion transporting polypeptide B3 (OAPTB3) transporter of amatoxin into human hepatocytes.
Rifampicin. Both rifampicin and high dose penicillin G have been shown in in vitro studies to be inhibitors of OAPTB3 transporter and in one study, rifampicin was shown to be a more potent inhibitor of OATPB3 mediated uptake of amatoxin.
Zuker-Herman R et al. Intravenous rifampicin use in the management of amanita phalloides toxicity. Clin Tox 2021; in press. https://doi.org/10.1080/15563650.2021.1887492