Comparative in vitro activity of tobramycin, gentamicin, kanamycin, colistin, carbenicillin, and ticarcillin and clinical isolates of Pseudomonas aeruginosa: epidemiological and therapeutic implications

A clinical comparison of tobramycin and gentamicin sulfate in the treatment of ocular infections

We evaluated the safety and efficacy of tobramycin and gentamicin sulfate ophthalmic solutions in the treatment of patients with bacterial infections of the conjunctivas. In this double-masked study involving 66 patients, the two aminoglycosides were found to be equally safe and effective, although the in vitro data suggested that tobramycin may be more efficacious against Pseudomonas infections. Staphylococcus aureus and S. epidermidis were the most frequent isolates from the infected eyes (59.8% and 20.6%, respectively).

Plasmid-determined tobramycin and gentamicin resistance in strains of Pseudomonas aeruginosa from two Sydney hospitals

Strains of Pseudomonas aeruginosa resistant to gentamicin, tobramycin, streptomycin, and sulphonamide have been isolated from patients at two Sydney hospitals. The multiple resistance of all these strains was due to a transmissible plasmid. The significance of the identification of this plasmid, in this variety of strains and at two hospitals, for the treatment of Ps. aeruginosa infections is discussed.

Ticarcillin: a review of its pharmacological properties and therapeutic efficacy

Ticarcillin is a semisynthetic penicillin for parenteral administration. The antibacterial activity of ticarcillin is similar to that of carbenicillin except that it is two to four times more active in vitro against Pseudomonas aeruginosa, generally less active against Gram-positive cocci and more active against most Gram-negative bacilli. As the pharmacokinetics of ticarcillin and carbenicillin are also similar, ticarcillin should theoretically be clinically effective when administered at a lower dosage than carbenicillin. There is some evidence that ticarcillin is comparable in efficacy with carbenicillin when given in half to two-thirds the dosage, when the drugs are given in combination with an aminoglycoside and in clinical situations where these drugs are agents of choice. Ticarcillin has been used successfully in the treatment of complicated urinary tract infection, pulmonary infection in cystic fibrosis and bacteraemia and is effective when combined with an aminoglycoside in severe infections in patients with granulocytopenia. The efficacy in anaerobic infections is at present poorly documented, although preliminary results are promising. Tolerability has generally been good with hypokalaemia being the most frequently reported side effect. At the dosages used, bleeding and fluid overload have seldom occurred.

Comparative in-vitro activity of ticarcillin and carbenicillin against 100 clinical isolates of Pseudomonas aeruginosa

The in-vitro activity of ticarcillin was found to be greater than that of carbenicillin against 97 out of 100 strains of Pseudomonas aeruginosa which were recently isolated from clinical specimens at the Royal Perth Hospital complex. These results indicate that ticarcillin should be considered for use in place of carbenicillin for treating infections caused by P. aeruginosa.