Imipenem/cilastatin treatment of multiresistant Pseudomonas aeruginosa lung infection in cystic fibrosis.

Ten patients with cystic fibrosis and chronic broncho-pulmonary Pseudomonas aeruginosa infection received 45 mg imipenem/cilastatin per kg body weight/day, intravenously for two weeks. The treatment was safe with only minor side effects and clinical parameters improved considerably during therapy. In all patients resistance of Ps. aeruginosa to imipenem developed in the second week of treatment; in seven patients the therapy selected for a resistant strain and in three resistance developed in the original strain. The resistance persisted after cessation of treatment and thus the clinical usefulness of imipenem/cilastatin as monotherapy in CF-patients with Ps. aeruginosa seems to be limited.