Will dulera (formoterol and mometasone) significantly affect a methacholine challenge?

Yes: Should meds be stopped before a methacholine challenge? Yes. A methacholine challenge is used to diagnose asthma. Dulera (formoterol and mometasone) is a combination medication with a long-acting beta agonist and a steroid. Long-acting beta agonists should be stopped prior to testing for accurate results. Speak with your doctor to find out exactly how long you need to be off prior to testing (usually 2 days).