Laboratory and clinical studies on ticarcillin were performed with following results.
1. Antibacterial activity of ticarcillin against respiratory pathogenic bacteria isolated from sputum was measured.
1) MIC values against 80 strains of Haemophilus influenzae ranged from 0.1 to 0.78 μg/ml. Ticarcillin was active as much as ampicillin, and slightly superior to amoxycillin, carbenicillin and sulbenicillin. There was no resistant strain against ticarcillin.
2) Against sensitive group of 34 strains of Pseudomonas aeruginosa, the activity of ticarcillin was 2 times superior to sulbenicillin and 4 times superior to carbenicillin. But against resistant strains, MICs of ticarcillin were same as those of sulbenicillin and carbenicillin.
2. After intramuscular administration of ticarcillin 100 mg/kg in rats, the concentrations of organs reached peak levels at 15 minutes and they were the following order of kidney, liver, serum and lung. Two to 4 hours later, ticarcillin was not detectable in all organs.
3. Nine patients with chronic respiratory tract infections were administered ticarcillin by intravenous drip infusion, and the concentrations in serum, saliva, sputum and intrabronchial secretions were measured. Serum levels of ticarcillin showed dose response according to administration dose volume and instillation time. The half life in serum was between 40 to 60 minutes. Probenecid prolonged the half-life of ticarcillin in all 4patients, and elevated the sputum level, too.
4. Ten patients with chronic respiratory infections (chronic bronchitis; 3, bronchiectasis; 3, chronic bronchiolitis; 4) were treated with intravenous drip infusion of ticarcillin 3 to 20 g a day for 5 to 14 days. Treatment succeeded in all of 8 patients infected with Haemophilus influenzae, and in one of 5 patients infected with Pseudomonas aeruginosa. Effects of ticarcillin for bacterial respiratory infections depended on transported concentration into infected bronchus and susceptibility of causative agents to ticarcillin.
5. There was no adverse reaction.
