Hi, Thank you for asking I understand quite well your concerns, so first I want to explain some facts about hypothyrodism: Patients with primary hypothyroidism have elevated TSH levels and decreased free hormone levels. Patients with elevated TSH levels but normal free hormone levels or estimates are considered to have mild or subclinical hypothyroidism. A low level of thyroxine and high level of TSH indicate an underactive thyroid. That s because your pituitary produces more TSH in an effort to stimulate your thyroid gland into producing more thyroid hormone. While talking about your drug interaction between levothyroxine and digoxine, your thyroid medicine may decrease the effects of your digoxin.The cause of the interaction is not known. Please consult your endocrinologist again or your cardiologist, in oder to change one of the medications. Dr. Ermira BIU