From the FDA Drug Label
Seizures have been reported rarely with the institution of levothyroxine therapy
- Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormones.
- The provided drug labels discuss the potential effects of levothyroxine therapy, which is used to treat hypothyroidism.
- The labels mention that seizures have been reported in some cases, but this is associated with the institution of levothyroxine therapy, not directly with hypothyroidism itself. The FDA drug label does not answer the question.
From the Research
Yes, hypothyroidism can trigger seizures, particularly when it's severe or left untreated, as evidenced by a recent study published in 2025 1. Severe hypothyroidism, known as myxedema, can lead to seizures as the brain requires adequate thyroid hormone for proper neurological function. Low thyroid hormone levels can disrupt the brain's electrical activity and metabolism, creating an environment conducive to seizure activity. This is more common in cases of profound hypothyroidism or myxedema coma, which is a medical emergency. Some key points to consider include:
- The relationship between hypothyroidism and seizures is complex and influenced by various factors, including the severity of hypothyroidism and the presence of other medical conditions 1.
- Treatment involves thyroid hormone replacement, typically with levothyroxine (T4), starting at appropriate doses based on age, weight, and severity of the condition.
- For adults, typical starting doses range from 25-100 mcg daily, gradually increased until thyroid function normalizes, as recommended in recent guidelines 2, 3.
- In emergency situations with seizures, intravenous thyroid hormone may be necessary, highlighting the importance of prompt medical attention in such cases.
- Proper management of hypothyroidism through regular medication and monitoring can prevent such neurological complications, emphasizing the need for ongoing care and evaluation 4, 5. It is essential to note that while some studies suggest potential benefits of combined levothyroxine and liothyronine therapy, the current evidence does not support this as a standard treatment approach for hypothyroidism, except in specific cases where patients may have a polymorphism in the DIO2 gene 4. Overall, the management of hypothyroidism requires careful consideration of individual patient needs and close monitoring to prevent complications, including seizures.