Which is a common endocrine side effect of lithium therapy?

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Multiple Choice

Which is a common endocrine side effect of lithium therapy?

Lithium commonly affects thyroid function, leading to hypothyroidism. It can accumulate in the thyroid and interfere with the synthesis and release of thyroid hormones, which may lower T4/T3 levels and cause a rise in TSH, sometimes with a goiter. Clinically, patients may have fatigue, weight gain, or cold intolerance, and laboratory testing often shows elevated TSH with or without low free T4. Because of this risk, baseline thyroid testing and regular monitoring of TSH (and free T4) are recommended during lithium therapy. If hypothyroidism develops, treating with levothyroxine is usually effective while continuing lithium, with dosing guided by TSH and free T4 levels. The other options reflect hematologic or electrolyte effects rather than endocrine ones, so they are not typical endocrine side effects of lithium.

Lithium commonly affects thyroid function, leading to hypothyroidism. It can accumulate in the thyroid and interfere with the synthesis and release of thyroid hormones, which may lower T4/T3 levels and cause a rise in TSH, sometimes with a goiter. Clinically, patients may have fatigue, weight gain, or cold intolerance, and laboratory testing often shows elevated TSH with or without low free T4. Because of this risk, baseline thyroid testing and regular monitoring of TSH (and free T4) are recommended during lithium therapy. If hypothyroidism develops, treating with levothyroxine is usually effective while continuing lithium, with dosing guided by TSH and free T4 levels. The other options reflect hematologic or electrolyte effects rather than endocrine ones, so they are not typical endocrine side effects of lithium.

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