TOBI® (tobramycin) inhalation continuously

Question

Hello,

I have question regarding the inhalation of TOBI® (tobramycin). I am 31 years old and have CF. Bacteria are Staphylococcus aureus and sometimes Pseudomonas. Since 3 years I am inhaling tobramycin using the following dosage regimen: 28 days twice a day 300mg, 28 days without tobramycin. During the break my condition is worsening and I also have problems due to an urge to cough after the break when I am beginning again with tobramycin. I read that some patients only inhale tobramycin once a day but continuously. Is that a way to do it? Is this a new trend? The health insurance does not pay me the continuous use of tobramycin (using it twice a day). To use Cayston® (aztreonam-lysine) or Colistin during the break is not a good option because my Staphylococcus aureus is resistent against them. Is it better to inhale tobramycin continuously or using the on/off dosage regimen? Is it necessary to have a "washing-out cycle" after a couple of months?

Many thanks

Answer

Hello,

You are right, some patients actually inhale tobramycin once a day continuously. However, the approval is only given for ON/OFF therapy.
If Staphylococci play a role that you are feeling worse during the OFF phase of tobramycin, then it should be considered to cover this time with an oral antibiotic that is effective against Staphylococci. If rather Pseudomonas is playing a role, then the inhalation with Colistin or Cayston® (aztreonam-lysine) would be an alternative - this should be discussed with your CF doctor. Studies have not yet shown conclusive effects of a continuous therapy with tobramycin used once a day and therefore most out-patient clinics do not use this regimen on a regular basis. It is for sure not a new trend but rather plays a role if patients do not have the time to do the inhalation twice a day or if - like in your case - there is a worsening in the OFF-phase. It has to be considered, though, that the resistance rate of Pseudomonas against tobramycin can increase or develop quicker if the OFF-phase is skipped.
As you can see it is not easy to give a recommendation. You should discuss all these points with your CF doctor considering the background of the two germs and their resistances as well as the whole clinical picture (is lung function worsening during the OFF-phase) and then decide.

Best regards,
Prof. Dr. Joachim Bargon

17.04.2012