Disclosed is a transdermal preparation in which a basic anti-inflammatory agent is blended. The transdermal preparation is an adhesive patch for external use, which has excellent drug release properties without deteriorating the physical properties of the plaster. The transdermal preparation is capable of achieving high release properties for the basic anti-inflammatory agent without deteriorating the release properties for a local anesthetic. Specifically disclosed is an adhesive transdermal patch which is characterized by containing both a basic anti-inflammatory agent and a local anesthetic that serves as an absorption enhancer for the basic anti-inflammatory agent. The basic anti-inflammatory agent has an acid dissociation constant (pKa) of not less than 7. The basic anti-inflammatory agent is contained therein in an amount of 0.1-10% by weight relative to the total weight of the drug-containing plaster, and the absorption enhancer is contained therein in an amount of 0.01-20% by weight relative to the total weight of the drug-containing plaster.
