Methacholine Challenge/ Advair

I have a question regarding Advair and it's effects on the Methacholine Challenge. I had a Methacholine Challenge done this past Monday, which was negative for asthma, but I had been using 1 puff of Advair once a day and stopped taking it for 36 hours before doing the MC. Do you think that 36 hours is enough time to allow the Advair to clear my system before taking the test? I guess there would be traces still left in my lungs, but not enough to effect the results of the test, right?

Thanks

[National Jewish Health]

I am not certain but I doubt that discontinuation of Advair™ Diskus® (fluticasone propionate and salmeterol) Inhalation Powder 36 hours before a methacholine challenge would guarantee the absence of an anti-inflammatory effect of Flovent® HFA Inhalation Aerosol (fluticasone propionate).  Even were the last dose of medicine to be out of your system there might be a significant lapse time between discontinuation of the medicine and the return of full-blown inflammation of the airways.  I would be reluctant to interpret this as a negative methacholine challenge.  I would be much more confident of a negative challenge, following discontinuation of the Advair™ Diskus® (fluticasone propionate and salmeterol) Inhalation Powder for 10 days or more.