[Secondary effects of lithium on thyroid function. Mechanisms, diagnostic and treatment (author's transl)].

The authors reviewed the literature concerning the side effects of lithium on thyroid function. Two kinds of side effects are reported: the first ones are minor, temporary, without important modification of thyroid function and must not be treated; the second ones are major and followed by hypothyroidism. This situation is mostly in relation with the preexistence of an autoimmune thyroiditis or another thyroid abnormality. The authors describe the mechanisms responsible for lithium side effects, suggest different thyroid examinations that should be done in patients before and during lithium therapy and discuss the indications of thyroxine administration.