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I think my methacholine test got messed up

My doctor thinks I have severe asthma. The daily medications that I’ve tried all help a little bit but not enough, I feel less reactive to triggers but I still have symptoms every day. My rescue inhaler and nebulizer rarely work for more than 4 hours and sometimes last less than 1 hour. Sometimes they work wonders but oftentimes they only give me partial relief or what seems like no relief at all.

I was sent for a methacholine test to confirm whether or not I have asthma and for my insurance if I end up needing biologics but I was squeezed into a last minute spot and had been taking trelegy for a days. I had my last dose less than 24 hours before the test and I had no reaction to the methacholine.

Is it possible for the trelegy to cause me to have no symptoms or lung function changes from the methacholine? I’m nervous because if I don’t have asthma then I’m probably stuck with all these symptoms while my doctors figure out what’s wrong with me. I feel like if I truly have asthma then I would have had some sort of response and my follow up with the doctor is still a few weeks away.

  1. Thanks for starting this conversation! I'm sorry to hear you are having such a hard time with your asthma right now. I totally understand the frustration when your daily symptoms vary so much day to day. One of our HCP moderators will likely have a better answer than me to this question (I'm just a way too seasoned patient) but I would imagine that if your maintenance medication is working properly, you might have more normal test results as compared to when you are not controlled/flaring. I have not ever had a methacholine challenge myself so I'm sorry I can't be of much help! Hope you get some answers soon. -Corinne, moderator

    1. thank you!

  2. HI. Thank you for posting about your own personal experience with us and for your great question. How long before the test did you use your trelegy. The methacholine challenge is meant to cause an asthma attack - and then this is quickly reversed by using rescue medicine like albuterol. This is perhaps the best test for diagnosing (or ruling out) asthma. Bronchodilators work to keep your airways open, and therefore can interfere with the test. Usually, before the test, your doctor will notify you of how long before the test to refrain from using any bronchodilator inhalers. I think that most hospitals request that you stop taking rescue inhalers like albuterol 4 hours prior to testing and refrain from using long-acting bronchodilators (such as what is in Trelegy) 8 hours before testing. Your doctor may have other guidelines. So, this may be something worth discussing with your doctor. And I am very curious to hear what your doctor says .What do you think? John. asthma.net community moderator

    1. hi John, thanks for your reply. I took the trelegy around 20 hours before the test. I was scheduled for the test the day of so they didn’t really give me any instructions. They just asked if I had used any inhalers or had caffeine/chocolate that day, which I hadn’t. I looked up some patient instructions from other places, they said that the LAMA medications should be stopped a whole week before the test! Maybe most people going for a methacholine test aren’t on strong daily medications so they didn’t ask me about mine?


    2. Hi Exoenti - and thanks for your response and further explanation. This does sound to be a bit unusual. However, I would also suggest, as my colleague , has mentioned, that you move forward and discuss this with your physician.
      It would not be unreasonable to have the PFT - methacholine challenge repeated. However, I think that discussing all this with your doctor may help to understand more about how the doctor is thinking and how he plans to approach this.
      What do you think?
      Leon (site moderator asthma.net)

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