PHARMACEUTICAL OR ANIMAL DRUG COMPOSED OF BACMECILLINAM AND OTHER BETA-LACTAM ANTIBIOTIC SUBSTANCE FOR ORAL ADMINISTRATION

PURPOSE:To provide the titled drug containing bacmecillinam or its salt in combination with other oral beta-lactam antibiotic substance or its salt, and exhibiting remarkable synergistic effect to the antibacterial activity in living body. CONSTITUTION:A pharmaceutical or an animal drug having synergistic effect to Gram-positive and Gram-genative bacteria can be obtained by using bacmecillinam or its salt (e.g. mineral acid salt such as hydrochloride) in combination with other orally administrable beta-lactam antibiotic substance (e.g. amoxycillin) or its salt (e.g. sodium salt, potassium salt, etc.) at a weight ratio of 1:(0.1-20). Dose: preferably 40-500mg of bacmecillinam and 0.5-3g of other beta-lactam antibiotic substance daily. It can be administered in the form of capsule, tablet, granule, troche, etc. The Gram-positive or Gram-negative bacteria are e.g. Serratia marcescens, Escherichia coli, Proteus mirabilis, etc.