Some MEDICINES MAY INTERACT with Synthroid. Tell your health care provider if you are taking any other medicines, especially any of the following:
Many prescription and nonprescription medicines (eg, used for infections, inflammation, aches and pains, nasal congestion, asthma, high blood pressure, irregular heartbeat or other heart problems, blood thinning, mental or mood problems, depression, diabetes, other thyroid problems, high cholesterol, hepatitis, weight loss, heartburn, birth control, hormone replacement therapy, growth hormone deficiency, cancer, seizures), and multivitamin products may interact with Synthroid, increasing the risk of side effects or decreasing effectiveness.