I posted recently about how tired I was feeling now I was on a BP medication. I also posted at the weekend with my new blood results that showed a drop in T3 regardless of a small drop in TSH and rise in T4. Suddenly I was 64% through the T4 reference range and only 27% through the T3 reference range. This was cause for concern and I was coming to terms with needing to add T3 to my medication.
I've been reluctant all week to start. I had been looking for information about BP medication and found nothing. Then last night I hit the search terms "calcium channel blocker + thyroid" and there it is! Not much research has been done, but research on rats and rabbits show that calcium channel blockers reduce the efficacy of thyroid hormone production.
Then I found the case of the middle aged woman who was put on a CCB and also medication for her diabetes. She was not hypothyroid. She was on the 2 medications for 4 years, by which time she had developed hypothyroidism, with no anti-bodies, familial history or other markers. She was put on 50mcg Levo. and her BP medication was switched to an Ace Inhibitor and monitored. After 1 year on the Levo she was carefully weaned off and her thyroid was working normally again.
omicsonline.org/proceedings...
I was already hypothyroid and under-medicated with slight conversion issues going on, so it happened fast for me. I was OK for around 10 days before the fatigue hit. My theory is that the BP tablet has created bigger conversion issues for me and made my FT3 drop.
I will be trying to get back to the doctor's tomorrow to get the medication changed.
They should know this stuff!