7687 Fluctuating Thyroid Hormone Levels: The Unconventional Pill Cutter

Abstract Disclosure: W. Akhter: None. R. Alshantti: None. V. Taqi: None. J.L. Gilden: None. Introduction: There are various causes of fluctuating thyroid hormone levels in patients. Some of these causes include lab variability, missing doses of medications, taking vitamins or medications which may interfere with the absorption of levothyroxine such as protein pump inhibitors, taking it with food, or malabsorption, such as in the case of celiac disease and other malabsorptive diseases. This can result in high or low doses of levothyroxine being required to get thyroid hormone levels back to the normal range and can also lead to variable thyroid hormone levels despite taking levothyroxine regularly. Case Presentation: We present the case of a 51-year-old female who presented to the endocrine clinic for continued management and monitoring of postsurgical hypothyroidism due to the diagnosis of papillary thyroid cancer, now status post total thyroidectomy, with subsequent postsurgical hypothyroidism and hypoparathyroidism. Patient’s thyroid labs at her last visit showed suppressed TSH of < 0.008 uIU/mL(0.550 - 4.780) and elevated free T4 of 1.9 ng/dL( 0.89 - 1.76) so her Levothyroxine dose was decreased from 75 mcg daily to 75 mcg 6 days a week. Repeat TSH after 8 weeks was 0.38 uIU. When confirmed with the patient, she stated that she had the levothyroxine 150 mcg tablets at home, was taking instead of the 75 mcg, and had been cutting a small part of the tablet every day, around 1/8th and had been taking 7/8th of the 150 mcg tablet, equivalent to about 130 mcg. Patient admitted using a knife instead of a pill cutter to estimate and cut a small amount of the tablet. It was discussed with the patient that cutting tablets with knives is inaccurate and the patient was encouraged to comply with the recommended levothyroxine dose so that her thyroid function tests could be maintained at goal and any future dosage adjustments can be made accurately if needed. Subsequently, the patient was prescribed levothyroxine 137 mcg daily and was advised to take it as a whole tablet. And most importantly, she was to discard the 150 mcg tablets. Repeat labs after 4 weeks TSH of < 0.008 uIU/mL and elevated free T4 of 2.0 ng/dL. Dose was further reduced to 125 mcg daily. Repeat thyroid function tests TSH and free T4 were to be done after a few weeks. Discussion/Conclusion: Our case aims to raise awareness about how there are various factors that can lead to erratic thyroid hormone levels. It is therefore important to identify the underlying cause when we see patients with fluctuating thyroid hormone levels. Patient education is paramount. It is our role as physicians to always follow up the medication usage with our patients, help them understand how and why they are supposed to take the medications we prescribe, and ensure that they are equipped to correctly follow our recommendations. In our case, something as basic as a pill-cutter would have helped the patient take the correct dose of thyroxine. Presentation: 6/2/2024