Symptoms of over medicated levothyroxine?

Levothyroxine Excess. You didn't mention the dose you were taking and the number of tablets you had over medicated with so it's difficult to project if you have a dangerous situation going on. The usual signs and symptoms of thyroid toxicity are a racing heart where it feels like it's throbbing, nervousness, intolerance to heat, increase in blood pressure, insomnia, and irritability.