Drug-induced hypothyroidism

Hypothyroidism induced by some drugs (eg lithium, amiodarone, interferon alfa) can be reversible if the drug is stopped. For some other drugs (eg immune checkpoint inhibitors), hypothyroidism is less likely to be reversible. See also Drugs that influence thyroid hormones.

The decision to continue or stop the causative drug depends on the harms of ongoing hypothyroidism versus the benefit of the drug, the availability of alternative treatments, and the likelihood of reversing the hypothyroidism if the drug is stopped.

If the drug is continued or the hypothyroidism is not reversible, long-term concurrent levothyroxine treatment may be required. Treat drug-induced hypothyroidism with thyroxine replacement therapy.

If levothyroxine therapy is started, but the causative drug is subsequently stopped, assess the need for continued levothyroxine by stopping therapy and measuring serum thyroid stimulating hormone (TSH) concentration 4 to 8 weeks later. Restart levothyroxine if the serum TSH concentration increases.