Can taking medications skew the results of thyroid testing.

[cuttysark]

I have Sjogrens disease and am on low dose Prednisalone of 2.5 mg alternate days and also ten weekly injections of Depot Medrol 80mg.

I have also had a recent course of three days Ciprofloxacin 500mg for a biliary infection.

Is it possible those medications could alter the results of a thyroid blood test I am due to have next week? I have been borderline low in the past but results dismissed by NHS guidelines.

Would appreciate your thoughts on it. Many thanks.

[Barrister]

I have found that whenever I have either a steroid injection or a course of oral steroids, my TSH becomes suppressed. At first, my GP would get antsy and is sit on me reducing my thyroxine and the. Within a couple of weeks my TSH would be above 10 so increase thyroxine again - you know the see saw effect. But after this had happened several times he came around to my suspicions that it was caused by the steroids although neither of us have managed to find much in the way of research. I just know now that I don't go to get any thyroid tests done when I've had steroids recently. But that may not happen to you, I just know that's what happens for me. Clemmie

[Clutter]

Cuttysark,

Taking Ciprofloxacin + Levothyroxine can reduce absorption of Levothyroxine and cause TSH to rise and FT4 and FT3 to fall.

google.co.uk/search?q=cipro...

[cuttysark in reply to Clutter]

Thanks so much to you both for your comments. I will try to be completely off the Cipro and on the lowest dose of steroid possible at the time of the tests.