Why is clenbuterol dangerous to take if i have hyperthyroidism and taking 10mg of carbimazole daily?

Stimulation: Clenbuterol is an adrenaline-like drug used to treat asthma. Hyperthyroidism stimulates your body, and especially your heart, just like adrenaline. The combination of an adrenaline-like drug on top of hyperthyroidism can be too much for the heart, and cause arrhythmia, heart attack, etc. However, if the carbimazole is controlling the thyroid and you have need, it may be ok. Talk to your doctor