Study of histamine release induced by acute administration of antitumor agents in dogs.

The effects of eight antitumoral drugs known to cause anaphylactoid side effects in clinical use were studied in dogs. Blood pressure, heart rate, and blood and plasma histamine levels were monitored. L-asparaginase, methotrexate, 5-fluorouracil, bleomycin, and cisplatin had no effect on these parameters. Doxorubicin, Vehem (teniposide), and Vepeside (etoposide) induced hypotension, tachycardia, and a rise in histamine levels. In the cases of Vehem and Vepeside, the excipient (respectively, cremophor EL and tween 80) induced the same effects. These agents, like elliptinium, which had been previously studied, induce nonspecific histamine release--unlike the other drugs studied. The mechanism of clinically observed anaphylactoid side effects is discussed in the light of these findings.