Nissan Chemical Industries Limited

Norimasa Shudo

Ryozo Sakoda

Kiyotomo Seto

Shin-ichi Akiyama

Keizo Tanikawa

Takashi Matsumoto

Yasunori Asada

Masumi Nakamura

Pyrazolones derivatives

An agent for enhancing the drug effects of an antitumor drug, which comprises a compound of the formula I: ##STR1## or a pharmaceutically acceptable salt of the compound.

Phosphorus pyridine compound

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.

Drug effect-enhancing agent for antitumor drug

Compounds of the formula (I): ##STR1## in which the nitrogen-containing hetero ring portion is a 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 either a CO.sub.2 R.sup.8 group or 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 or antitumor drugs.

Growing community of inventors

Shiraoka, Japan

Norimasa Shudo