Synacthen test, some information please from those who have had one.

[Predsharer]

I am due to have a Short Synacthen test in a few days and I have read that it can cause side effects. I have experienced an anaphylactic shock as a result of an allergy to an ingredient in certain painkilling medications and am now concerned about having this test. Has anyone on this forum experienced any adverse effects during this test?

[SnazzyD]

I too was nervous because I seem to react with extra to every drug I have, which I think is dose sensitivity rather than allergy. The Synacthen drug gave me a fleeting feeling of anxiousness like a wave, a warm stomach for some seconds and a flush all over. After that nothing.

[PMRpro Ambassador]

I have never come across anyone with a severe reaction to it - just the usual waves of heat sensation. It is why it must be done in a clinic setting so emergency care is available in the very unlikely event of anything happening.

What dose of pred are you on now? Has your doctor done a basal cortisol test before sending you for the synacthen test? It gives reliable enough information to assess whether a synacthen test really is necessary and for more than half of patients it isn't required at that point. Even for the other half. it provides relevant information for patients still on pred which will, of course, suppress the cortisol production to some extent.

[Predsharer in reply to PMRpro]

Thank you for your reply PMRpro. I am currently on a very slow taper between 1.5mg and 1mg. Some days I am fine, but some days (and especially if I do too much or have a stressful day) I feel dreadful, tired, emotional achey etc. I had a Rheumatologist appointment in December and she suggested I have a Synacthen test and referred me for one, but didn’t mention a basal cortisol test.

[PMRpro Ambassador in reply to Predsharer]

It's just s simpler (and therefore cheaper and more easily accessible) indicator that just requires a simple blood sample to be taken at the GP.

pubmed.ncbi.nlm.nih.gov/286...

The synacthen test will tell you that your adrenals are CAPABLE of producing cortisol but not whether they are doing so in a reliable and consistent way. It sounds as if you are in that halfway house but all that will cure that is time. It is expected that it can take up to a year after you have stopped pred altogether for them to work reliably. Any stress will make you have a wobble - if the stress is severe enough, even at higher doses you can feel quite ropey when the spike of cortisol is missing or not enough.

[Predsharer]

I’m really not surprised that I am being sent for this test, when another simpler one would do. I have not had great care during my rather bumpy PMR journey. My GP, who used to be excellent is now absolutely buckling under the pressure of being a GP in the UK, has passed my care to a Rheumatologist who I see every four months. She asks me questions, writes up my answers, which form the basis of a letter which she writes to my GP. I get a copy of it and it is rarely an accurate account of what I’ve said!

I have had no advice and have relied on the good people on this forum to help me. I am OK though and, as you say, am in that tricky place where sometimes I have enough Pred to make my adrenals function OK and sometimes I feel really awful. I have pared back my life considerably to accommodate this process, which is quite depressing and isolating, but necessary.

You won’t be surprised to hear that the appointment letter from the hospital doesn’t even mention not taking Pred the morning of the test. I learned that from reading it on this forum.

I think that if no-one on here says that it caused them any harm, I will go for the test as it will inform the health professionals, if nothing else!

[PMRpro Ambassador in reply to Predsharer]

I think it is a case of "this is how it's always been done" - the work on replacing it with just basal cortisol is relatively recent and Covid also got in the way!

[powerwalk]

Ive had this done, no bad reaction at all and im a horror with meds. Good luck.

[krillemy]

I had no reaktion

[diana1998]

I had one done in the hospital at 9am. Took the pred with me with yoghurt and a banana and took my dose straight after. Felt nothing whatsoever. A piece of cake. Don't be nervous.

[Sho-Sho]

I have had 2 Synthacen tests done in the last few years & I had no reaction atall - just enjoyed the rest & a cup of tea & some biscuits in the treatment room!

[Yellow-dog]

I didn’t experience any side effects.

[Rugger]

I had a short Synacthen test during lockdown and had no problems at all. I hope it goes well for you. I took my pred with me to take with the cuppa they gave me afterwards - I don't remember any biscuits - take your own, just in case!!

[Longtimer]

I had no reaction from my test, very quick, but what I do remember is the lady sitting opposite me saying they don`t know why my cortisol levels are low, she said I`m not on steroids like you, I have steroid inhaler for asthma (for years)......to which I replied I had read that the inhaler affects cortisol just the same. She said I wonder why my GP dosen`t know that!....no surprise there then!....