By Steve Edelson
Staff writer

Some physicians prescribe PathoGenesis Corp.'s TOBI tobramycin to treat pseudomonal lung infections in cystic fibrosis patients as directed on the label: 28 days on and 28 days off. But others are reluctant to prescribe a chronic CF treatment for fear of developing TOBI-resistant strains of pseudomonas. This reluctance has caused some physicians to either prescribe TOBI for exacerbational use only or to abstain from prescribing it until long-term data on TOBI's resistance profile are available.