Theophylline (and query about lung function tests)

[Mogget]

Hello all,

I saw a consultant today who has prescribed theophylline. I've just read up on it and note on the Asthma UK site that regular blood tests are recommended to keep an eye on dosage levels... my consultant never mentioned this. Can anyone on theophylline advise whether they have regular blood tests to keep an eye on things?

Xolair has also been mentioned BUT my lung function tests (spirometry and FeNO) keep coming back as normal and the consultant I saw today said more evidence needs to be built if I'm to be put forward for it. So he's booking me in for a mannitol challenge. He did even vaguely question whether I had asthma... it's frustrating because I certainly feel like I have asthma and salbutamol brings me relief. My symptoms are at their worst overnight - can lung function tests during the day when I often feel largely asymptomatic (unless exercising or in contact with triggers) therefore return a 'normal' reading?

Thanks

[EmmaF91 Community Ambassador]

Hi

Advice for theophylline regarding BTs is usually get 1 5-7 days after starting it, and about 4hrs after taking the tablet. If theses levels come back therapeutic they may not retest I was you get issues, or (if you have a proactive GP) it may be every 6-12 months. If you seek to your GP they should go through it but if they don’t ask.

Yes you need a LFT to indicate asthma before being put forward for xolair (as well as needing a high IgE level shown in a BT). I have severe asthma but on the right day/time/month, my LFT can be ‘normal’, and my spiro better than predicted (however my FeNO is always borderline or high when I have done it 😅). My first LFT (whilst asymptomatic) showed nothing, but then I went for a mannitol whilst symptomatic and it got cancelled due to ‘obvious’ asthma being shown on the baseline test.

I hope that helps explain things a bit. Good luck

[Mogget in reply to EmmaF91]

Thanks Emma - that's really helpful! Just called my GP surgery and the earliest appointment available is 15 March (rolls eyes). I wonder if I would be ok to just start the tablets and keep an eye on side effects (as per the consultant's advice after all...)?

I have the high IgE level. That's interesting... thanks for your advice.

[EmmaF91 Community Ambassador in reply to Mogget]

You can take the theophylline now if you like, just be aware of the side effects to look for (headaches, nausea, ‘spacey’, dizzy, palps etc) so you can report are problem and spot if your levels are too high.

Good luck ☺️

[Matman]

While I can't specifically answer your Theophylline Question, I too am considering it as - along with Montelukast (which I already take) - it seems to be particularly useful for aiding depletion of Eosinophils, a type of white blood cell that instrumental in 50% of Asthma Patients 'Asthma'. (I suffer from Eosinophilic Asthma)

The 'doubt / hesitation' over your Diagnosis, does not surprises me. NICE itself, don't yet have a firm 'definition' for Asthma (of which there are several kinds). Asthma also frequently overlaps with several different respiratory and 'other' conditions too (especially 'other' conditions that involve the nasal airways and sinuses).

These days it seems better to 'self-classify' oneself using a more generic term - such as 'Respiratory Disease' - rather than Asthma. Many 'Asthmatics' have a variety of Respiratory Symptoms, that can't entirely be defined as 'Asthma'. Unfortunately, the Sub-Class Categorisations (Phenotypes / Endotypes) tend also to overlap in many cases. As yet, they are still, somewhat, inaccurate, due - in no small part - to the fact that Testing for 'Asthma Type' is not yet an exact science, despite 'Tests / Imaging' such as: Spirometry; CT; FeNO, Bloodwork etc.

[Mogget in reply to Matman]

Thanks for your reply Matman. It seems the medical profession is only really at the start of beginning to understand the complexity and nuances of asthma...

[Lysistrata Administrator Community Ambassador]

I've been on them for over 5 years (Phyllocontin brand extended release aminophylline) and love them - no side effects, have occasional blood tests, mainly when I'm admitted and someone gets worried about my heart rate (spoiler alert: asthma, not Phyllocontin. I pointed out to consultant and registrar who were dubious about it especially given HR that my HR behaves most of the time on them but definitely doesn't behave with asthma!). Also had occasional blood tests in the asthma clinic but wouldn't call it a regular/burdensome requirement, though if you do have them done the timing is important so they know whether it's a peak or a trough level.

The main concern seems to be whether you may be toxic as they can be helpful even below the supposed therapeutic level. It's very individual though as people seem to process and react to them differently. They are a bit 'old fashioned' and something of a Marmite drug for both patients and doctors, but I would say worth a try. I do try to make sure I take them roughly 12 hours apart though - I pick a time and put a phone alarm on.

They appear to have several effects including anti-inflammatory but also direct bronchodilating properties. My asthma is non-eosinophilic and non-allergic and responds to them.

Hope this helps - and hope the tablets help! One last thing if you haven't been told this - make sure you get the same brand every time unless you've discussed switching with the consultant. They all have slightly different dosages so you need to be sure to stick with one brand at a time (unlike other drugs where the generic drug can be prescribed so you would eg be prescribed salbutamol and might get Ventolin or Salamol.) The dosage can be adjusted by switching to another brand if needed.

[Mogget in reply to Lysistrata]

Thanks for the advice. That's good to hear that you love the tablets! And yeah, it's frustrating that fast HR isn't a widely recognised symptom of an asthma flare.

I wasn't aware of the brand tip - thanks. I've taken my first dose today and will look out for side effects, and will ask my GP about blood tests when I see them in March.