[Do lithium salts have a place in the treatment of severe hyperthyroidism? (author's transl)].

In a patient with hyperthyroidism resulting in cachexia, severe cardiac complications and functional renal failure, and a second case of hyperthyroidism refractory to carbimazole as a result of iodine overload, the administration of 1 to 3 g of lithium gluconate every 1 to 3 days, in association with carbimazole, led to persistent clinical and biological improvement in 8 to 16 days. In the first case, the course was complicated by neurological intolerance (blood lithium 0.98 mEq/l) which responded to the temporary interruption of treatment and by a transient escape of thyroid function from the effects of lithium which disappeared after a slight adjustment in the dose. In the second case, the course under treatment was favourable from the outset. Thus in forms of hyperthyroidism in which usual forms of treatment are inadequate and where there is a risk of "acute crises", lithium may be valuable as adjuvant therapy. If the dose is regularly modified in order to obtain a daily blood lithium level of less than 0.60 mEq/l, and on condition of close clinical, electrocardiographic and ionic surveillance, cardiac and renal failure and neuropsychiatric disturbances do not prevent the use of lithium, which the authors feel to be of irreplaceable value.