Lithium as an Alternative Option in Graves Thyrotoxicosis

Area of Science:

• Endocrinology
• Internal Medicine
• Pharmacology

Background:

• Graves thyrotoxicosis is an autoimmune disorder causing hyperthyroidism.
• Methimazole is a common treatment but can cause severe side effects like fulminant hepatitis.
• Alternative treatments are needed for patients intolerant to thionamides.

Purpose of the Study:

• To evaluate the efficacy and safety of lithium in managing Graves thyrotoxicosis.
• To assess lithium's role as an alternative therapy when methimazole is contraindicated.
• To determine if subtherapeutic lithium levels can maintain a euthyroid state.

Main Methods:

• A 67-year-old female patient with Graves thyrotoxicosis developed fulminant hepatitis after methimazole initiation.
• Lithium carbonate was administered at 300 mg daily, aiming for therapeutic levels (0.4-0.6 mEq/L).
• Concomitant treatment included hydrocortisone and propranolol; lithium levels and thyroid function were monitored.

Main Results:

• The patient achieved biochemical and clinical euthyroidism within 8 days of lithium initiation.
• Lithium successfully controlled hyperthyroidism for over a month, even at subtherapeutic levels.
• Discontinuation of lithium led to rapid recurrence of thyrotoxicosis, demonstrating its efficacy.
• No signs of lithium toxicity were observed during treatment.

Conclusions:

• Lithium is a viable and effective treatment option for Graves thyrotoxicosis, particularly in patients who cannot tolerate thionamides.
• Subtherapeutic lithium levels may be sufficient to maintain a euthyroid state, reducing the risk of toxicity.
• Lithium offers a crucial therapeutic alternative while awaiting definitive treatments like radioiodine ablation.