Drug effect-enhancing agent for antitumor drug

摘要

Compounds of the formula (I): ##STR1## in which the nitrogen- containing hetero ring portion is 1,4-dihydropyridine ring or a pyridine ring, R.sup.1 is only present when the nitrogen-containing hetero ring is a 1,4-dihydropyridine ring, and Z is a group of the formula (II): ##STR2## in which R.sup.4 and R.sup.5 may be the same or different and together may form one divalent group, are effective agents for enhancing the antitumor effect of antitumor drugs.