Effect of Lugol’s solution on 131I therapy efficacy in Graves’ disease

Abstract

Purpose Lugol's solution could control thyroid function and suppress 131 I uptake in hyperthyroidism. This study aimed to investigate the appropriate time to withdraw Lugol's solution before 131 I therapy (RIT) in Graves' disease (GD) patients, and how this should in uence thyrotropin receptor antibodies (TRAb), 131 I uptake and RIT outcome.Methods Two groups (125 cases and 1805 cases) of GD patients reveived RIT, who were pre-treated with and without Lugol's solution (RI-CI group and RI group). The RI-CI group was further divided into the following sub-groups depending on the duration span between Lugol's solution withdrawal and RIT: sub-roup A, 4-7 d (n = 49); sub-group B, 8-14 d (n = 41); and sub-group C, 15-30 d (n = 35). The highest radioactive iodine uptake rate (RAIU max ), effective half-life (T eff ), TRAb, and free triiodothyronine (FT 3 ) and free thyroxine (FT 4 ) levels were compared, and therapeutic outcome was evaluated.Results There were no signi cant differences in RAIU max , TRAb, and T eff among the four sub-groups (P > 0.05). Both FT 3 and FT 4 levels in sub-groups A and B were lower than those in group RI and sub-group C (P < 0.05). The outcome of non-hyperthyroidism (euthyroidism + hypothyroidism) in groups RI-CI and RI were signi cantly different at post-RIT month 1 and 3 (P < 0.05). However, intergroup differences at 6 and 12 months were not signi cant (P > 0.05).Conclusions Withdrawal of Lugol's solution 4-7 or 8-14 d before RIT does not in uence 131 I uptake and RIT e cacy in GD. Moreover, in order to avoid a rapid increase in thyroid hormone levels at the same time, Lugol's solution should be withdrawn 4-7 d before RIT. BackgroundThe treatment of hyperthyroidism or Graves' disease (GD) by 131 I is a widely accepted approach in cases with preserved iodine uptake capacity of the thyroid gland [1, 2]. However, in GD patients with aggravated symptoms, immediate 131 I therapy (RIT) may be a risk factor for hyperthyroidism crisis if pre-treatment is not administered.Lugol's solution (containing 5% iodine and 10% potassium iodide) can quickly affect the iodine metabolism in the thyroid, decrease the iodine pool, prevent iodine uptake, inhibit proteolytic enzymes, reduce thyroglobulin decomposition, inhibit the synthesis and release of thyroid hormones, and quickly suppress serum thyroid hormone levels. Lugol's solution can also reduce blood ow to the thyroid gland, antagonize glandular congestion, and shrink and harden the gland. Clinically, Lugol's solution is often used with the aim of pre-operative preparation in GD patients. Lugol's solution is also used in patients with precursor hyperthyroidism crisis, hyperthyroidism patients with liver damage, neutropenia or other severe complications after antithyroid drug (ATD), and patients with aggravated symptoms after RIT.However, the use of Lugol's solution shall affect 131 I uptake and the e cacy of RIT in GD patients. Hence, the appropriate commencement and secession of Lugol's solution as a pre-treatment before RIT is an interesting

Application of oral inorganic iodine in the treatment of Graves’ disease

“…Lugol’s solution is a composite iodine solution consisting of elemental iodine (5%), potassium iodide (10%) and distilled water. Since the solution tastes bitter and is irritating to the gastrointestinal tract, it is often recommended to fully dilute it with a sweet drink ( 3 ). In the clinic, inorganic iodine is generally used as an adjuvant in antithyroid drugs (ATDs); however, the effect of inorganic iodine alone on GD remains to be evaluated ( 4 ).…”