The purpose of the present invention is to provide a polymer gel that can increase drug content ratio and reduce undesirable influence on gel strength and shape stability after the drug release, compared with the conventional techniques. The purpose can be achieved by an anionic drug-containing medical device comprising: (1) an anionic drug； and (2) a copolymer which contains, as constituents, a cationic monomer comprising a condensation product of an alkyl quaternary ammonium compound having a substituted or unsubstituted aralkyl group and (meth)acrylic acid or a salt of the condensation product and a monomer capable of copolymerizing with the condensation product or the salt of the condensation product.
