Which of the following is an expected side effect of lithium?

Which of the following is an expected side effect of lithium?

• A. Weight gain
• B. Hypertension
• C. Diarrhea
• D. Rash

Answer: (A)

Weight gain is a common, expected side effect of lithium. This medication can affect thyroid function, often causing hypothyroidism, which slows metabolism and promotes weight gain. It can also increase appetite and cause fluid retention, both of which contribute to added pounds. Because of this, monitoring weight and thyroid function (TSH and free T4) is routinely done in patients on lithium. Hypertension, diarrhea, and rash are not typical or defining adverse effects of lithium, though mild GI upset can occur for some patients. If weight gain becomes a concern, clinicians may adjust treatment or address thyroid function and lifestyle factors.

Weight gain is a common, expected side effect of lithium. This medication can affect thyroid function, often causing hypothyroidism, which slows metabolism and promotes weight gain. It can also increase appetite and cause fluid retention, both of which contribute to added pounds. Because of this, monitoring weight and thyroid function (TSH and free T4) is routinely done in patients on lithium. Hypertension, diarrhea, and rash are not typical or defining adverse effects of lithium, though mild GI upset can occur for some patients. If weight gain becomes a concern, clinicians may adjust treatment or address thyroid function and lifestyle factors.