How do you approach the use of chronic azithromycin in patients with CF who may require therapy with IV tobramycin in the future?

This question has been somewhat analyzed in the TEACH study comparing coadministration of azithromycin and inhaled tobramycin. The authors found no difference in lung function but higher pseudomonas CFU reduction in patients treated with inhaled tobramycin alone. In the situation of IV tobramycin fo...