From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Restarting a patient on 100 micrograms of levothyroxine after a 4-month discontinuation is not generally recommended without reassessment. The patient should have their thyroid function tested with TSH and possibly T4 levels before restarting treatment, as suggested by the most recent and highest quality study available 1. After a 4-month gap, the patient's thyroid status may have changed, and the previous dose of 100 mcg might no longer be appropriate.
Key Considerations
- The patient's thyroid status should be reassessed before restarting levothyroxine treatment.
- If testing confirms the need for levothyroxine, it's often safer to restart at a lower dose (such as 25-50 mcg daily) and gradually increase every 2-4 weeks based on symptoms and follow-up lab results, especially in older adults or those with cardiovascular disease.
- The reason for the original discontinuation should also be investigated, as this might influence the decision about restarting therapy and appropriate dosing.
Potential Risks
- Sudden reintroduction of a full dose of levothyroxine can lead to potential adverse effects such as heart palpitations, anxiety, or cardiac complications.
- Interactions with other medications, such as acetaminophen and sunitinib, should be considered when restarting levothyroxine treatment, as reported in a case study 2.
Clinical Approach
- A cautious approach to restarting levothyroxine treatment is recommended, taking into account the patient's individual needs and medical history.
- Regular monitoring of thyroid function and adjustment of the levothyroxine dose as needed can help prevent adverse effects and ensure optimal treatment outcomes.