Use of Levothyroxine in Patients with Subtotal Thyroidectomy: A Systematic Review Levothyroxine After Subtotal Thyroidectomy

Abstract Introduction: Subtotal thyroidectomy preserves glandular tissue intending to maintain hormonal autonomy; however, the viability of the remnant is unpredictable, complicating postoperative pharmacological management. Objective: To analyze available scientific evidence on the indication, dosage regimens, and clinical outcomes of levothyroxine use in patients undergoing subtotal thyroidectomy. Methodology: A systematic review was conducted following the PRISMA 2020 statement. A search in indexed databases (PubMed, Scielo, ScienceDirect, Cochrane) identified 50 relevant studies published in the last 5 years. Results: Evidence indicates that a significant proportion of patients develop late-onset hypothyroidism due to remnant exhaustion or require suppressive therapy to prevent goiter recurrence. Unlike total resection, dosing is complex and empirical, with a high risk of iatrogenic subclinical hyperthyroidism due to overtreatment, impacting cardiovascular and bone health. Conclusions: Levothyroxine therapy is frequently necessary and effective but demands strict TSH monitoring to personalize dosage, balancing recurrence prevention with patient safety.