Which of the following patients can be safely prescribed lithium therapy to treat bipolar disorder?

• A. A patient with normal kidney and thyroid function and no history of lithium allergy
• B. A patient with untreated hypothyroidism
• C. A patient with severe renal impairment
• D. A patient with a known allergy to lithium

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the clinical considerations for prescribing lithium therapy. Lithium is commonly used to treat bipolar disorder but requires careful assessment of kidney and thyroid function because lithium is primarily excreted by the kidneys and can affect thyroid function.
2. Step 2: Identify contraindications for lithium therapy. Severe renal impairment is a contraindication because lithium clearance is reduced, increasing the risk of toxicity. Similarly, untreated hypothyroidism is a concern because lithium can worsen thyroid function.
3. Step 3: Consider allergy history. A known allergy to lithium is an absolute contraindication, as it can cause severe adverse reactions.
4. Step 4: Evaluate the patient's health status. A patient with normal kidney and thyroid function and no history of lithium allergy is the safest candidate for lithium therapy.
5. Step 5: Conclude that only the patient with normal kidney and thyroid function and no lithium allergy can be safely prescribed lithium, while the others have conditions that contraindicate its use.