Prolonged use of anti-histamines can actually aggravate the thyroid and should be avoided unless really neccesary.
I'd be asking for your meds to be re-evaluated again.
20mg T3 is a high dose.
I wouldve thought 5mg T3 to 50mg T4 would be sufficient.
T3 can keep you awake and can also make you hyper if it is too large a dose.
Question as to why he has you on 20mg T3.
I've tried all the alternative sleeping solutions possible and nothing works that's why I have resorted to drowsy anti-histamines. My GP wanted me to take Amitriptyline but I am reluctant to go on an antidpressent as I get horrible side effects (was on it for 4 years and the dry, swollen mouth never subsided). I now know it is my thyroid meds that control my sleep as I did sleep when I was on 20mg T3 but I looked awful in a morning with huge dark circles and had to survive on coffee all morning to try and do my work. I am wondering whether I was prescribled too high a dose of T3 as I have read some people can only tolerate 5mg T3 and I was on 20mg! I think when I start sleeping properly is when my body will be regulated on my thryoid meds and goodness knows when that will be.
try some Lavendar Oil on your pillowslip....works wonders.
Or put a wheat pack with lavendar on it under your head where you sleep.