the one thing that people don't seem to understand is that TOBI and tobramycin are the same molecule.
so if you're using the "less aggressive" treatment of TOBI, you're still running the risk of developing resistance to Tobramycin. Since they're the SAME antibiotic.
talk to microbiologists. the latest thinking in that community is to be as aggresive as possible with antibiotics to PREVENT resistance. here's why:
dead bugs don't mutate.
that's it. they don't mutate. so let's say you take TOBI to destroy PA. some days the TOBI reaches the site of infection, and some days, becuase of sputum blocking the sit of infection, the TOBI doesn't reach the PA. so some days PA is being killed, and some days PA isn't. well, PA takes several days of antibiotic exposure to be killed. so the bacteria that survive day 1 of TOBI exposure, the miss TOBI exposure day 2, are, by natural selection, STRONGER bacteria. so the next round of anbitiotics may take longer or may not even work on the PA because stronger, more virulent PA have been bread by lack of consistent TOBI exposure. this is the nature of inhaled antibiotics.
don't get me wrong. TOBI is a fabulous drug. and i use it myself. however, i am not newly colonized.
let's look at IV tobramycin. it's typically administered in the hospital or at home with patients who are good at giving themselves treatment at regular intervals. now, there is no question that tobra gets to the site of the infection - because it's circulating in the blood stream. there is no mucus to block IV tobra exposure. the PA gets hit, and hit hard, with antibiotics for 14 days every day, at regular intervals. this is LESS likely to induce resistance becuase of the constant antibiotic exposure - ESPECIALLY in newly cultured PA patients.
if the PA isn't killed on day 1, it's exposed again on day 2 to the antibiotic. if isn't not killed on day 7, it's exposed to the tobra on day 10 to be killed. and so on and so on. if all the bacteria are DEAD (which they more likely will be with tobra than TOBI because of consistent, predictable antibiotic exposure) there is no chance for stronger, more virulent bacteria to survive. DEAD BUGS DON'T MUTATE. cuz they're dead.
so we all must re-think our fears of resistance.
and truthfully, most patients with CF don't die because of lack of antibiotic choices to kill bacteria (unless you have cepacia...that's a whole different story). they die of lung failure from their lungs being damaged over and over and over again by infections.
so if you can prevent PA colonization for an extra 12 months, 24 months, etc in a little CFers life, you are buying time.
being aggressive with antibiotics and preserving lung function is the way to go.
