Scheid W, Oppermann B, Traut H
Experientia. 1984 Jul 15;40(7):746-7. doi: 10.1007/BF01949756.
The induction of 2-break chromosome aberrations (dicentrics and ring chromosomes) in human lymphocytes by the antitumor agents bleomycin and peplomycin is strongly enhanced when those agents are applied together with the heart drug verapamil (isoptin).