Short versus long term effect of lithium on pituitary thyroid axis

ABSTRACT

Although the antithyroid effect of lithium is well known in thyrotoxicosis, there is no general agreement about its effect in euthyroid subjects. Furthermore, the duration of therapy may modify its antithyroid effect. In the thyrotoxic patients, short term use of lithium is effective and safe method to achieve euthyroidism. However, long term use needs close supervision and manipulation of the dose. In euthyroid patients even short term use of lithium is associated with subclinical hypothyroidism which is much more frequent than previously suggested and replacement thyroid therapy should be used from the start so as to avoid subclinical hypothyroidism and prevent fluctuations in the thyroid function that could induce affective disorders