In my search to find out what is wrong with me since November 2006. Doctors have not yet figured it out. The only thing one of the doctors has decided is that (first I had hypothyroid and hyperthyroid symptoms) and now they have decided that I have hypothyroid, They placed me on synthroid 50 mcg, which seems to make my problem worse. I started doing some natural stuff for my thyroid and when I go next week for my thyroid check I will know if it is working. I did not continue taking the synthroid at this time. The doctors can't figure out why my heart does the things that it does (races, drops beats, feels like it my heart trembles inside all of the time, feels like my heart stops for a second and then jumps back into starting, and then about every four months my heart with start beating with a fast rage and I wind up calling 911). They are now checking to see if it is cardiomyopathy. I will keep you posted, but in the meantime while I was doing research on the internet (which I don't gues doctors ever do) I found this interesting artcle below:
Histamine aggravated levothyroxine-induced cardiomyopathy in guinea pigs.
Hu HJ, Dai DZ, Shen YM.
Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, China.
AIM: To study effects of histamine on cardiomyopathy.
METHODS: Cardiomyopathy model was developed in guinea pig by i.p. levothyroxine 0.5 mg.kg-1.d-1 for 10 d. Langendroff's hearts were perfused. ECG and contractile force were recorded. Histamine (5 micrograms) was given by intra-aortic injection. Histamine content of coronary venous effluent was determined fluorometrically.
RESULTS: Attack of histamine on cardiomyopathy was severer than that in normal hearts. Tachycardia was more prominent; atrioventricular conduction block occurred earlier; decrease in coronary flow was more marked. Uptakes of histamine were 37% in the model and 19% in the normal hearts (P < 0.01).
CONCLUSION: Histamine aggravated levothyroxine-cardiomyopathy.
Generic Name: levothyroxine (LEE voe thy ROX een)
Brand names: Levothroid, Levoxyl, Synthroid, Unithroid
Zhongguo Yao Li Xue Bao. 1997 Mar;18(2):159-60
I then wondered if my symptoms got worse because of the synthroid