Thydin Drug Interactions

Cholestyramine, Aluminum, Magnesium and Ferrous Preparations and Ciprofloxacin: Decrease the absorption of levothyroxine resulting to decrease effectiveness. Levothyroxine Sodium Tablet (Thydin) should be taken 4 hours apart from these medications.
Phenytoin, Carbamazepine, Rifampicin and Barbiturates: Increase the biotransformation and elimination of levothyroxine.
Estrogens: Increase the serum concentration of thyroxine-binding globulin (TEG).
Lithium and Iodide: Decrease thyroid hormone secretion from the thyroid gland.
Propranolol, Amiodarone, some X-ray-imaging fluids and Dexamethasone: Inhibit enzyme responsible for the conversion of T4 to T3 causing decrease in T3 level, thus, therapeutic effect also decrease. For patients with hypothyroidism continuously taking Propranolol with Levothyroxine Sodium Table (Thydin), plasma level of Propranolol may decrease.
Antidiabetics: Require an increase dose of Insulin or other oral anti-diabetic drugs when taken with Levothyroxine Sodium Tablet (Thydin). Hypoglycemia may occur if the dose of Levothyroxine Sodium Tablet (Thydin) is lowered and the insulin or oral antidiabetics remain unchanged.
Anticoagulants: Increase the anticoagulant activity and therefore dosing of anticoagulant should be adjusted based on plasma protein binding. Dose may be re-adjusted if necessary.