The Effect of a Single Dose of Propylthiouracil (PTU), Methimazol (MMI), β-methasone and Iodine on Serum Thyroxine (T_4), 3, 3', 5-triiodothyronine (T_3) and 3, 3', 5'-triiodothyronine (Reverse T_3) in patients with Hyperthyroidism