Laboratory and clinical studies on T-2588, a new cephem antibiotic

Laboratory and clinical studies were carried out on T-2588, a newly developed oral cephem antibiotic. The following results were obtained. 1) Antibacterial activity The antibacterial activity of T-2588 was examined by the serial microbroth dilution method using MIC 2000 system (Dynateck Co.). The minimum inhibitory concentrations (MICs) of T-2588 against a total of 657 clinical isolates were compared with those of cefroxadine (CXD), cefaclor (CCL), amoxicillin (AMPC), norfloxacin (NFLX) and minocycline (MINO). The antimicrobial activity of T-2588 against gram-positive cocci was the most potent next to AMPC. T-2588 proved the most active against Enterobacteriaceae next to NFLX among the tested antibiotics. In addition, it was the most potent against H.influenzae and all the strains were inhibited to grow in the concentration of less than 0. 05 μg/ml. 2) Serum and sputum levels of T-2588 Two hundred mg of T-2588 was given orally to two patients with chronic bronchitis. The maximum serum levels were 3. 2 μg/ml in one patient and 0. 9 μg/ml in the other. The peak sputum concentration was obtained 3–4 hours after administration with the value of 0.084 μg/ml in one case. In the other case, all samples proved under the detectable limit of measurement. 3) Clinical evaluation and adverse reaction A total of 20 patients with respiratory tract infections (chronic bronchitis 11, pneumonia 3, bronchiectasis 3, diffuse panbronchiolitis 1, lung abscess 1 and respiratory infection + bronchial asthma 1) were given 300~600 mg of T-2588 daily for 6~18 days. The overall efficacy rate was 57.9% (good in 11, fair in 6, poor in 2 and unassessable in 1). Hematochemical tests, and renal and liver function tests were performed before and after administration of T-2588. No significant adverse reactions were observed. However, one patient showed slight and transient eosinophilia.