LBODP105 A Case of Significantly Increased Levothyroxine Requirement With Rifampin Therapy

Abstract Introduction Rifampin has a wide range of drug interactions through increased hepatic microsomal enzyme activity. We are reporting case patient with post-surgical hypothyroidism on stable thyroid hormone replacement therapy who required significantly higher doses levothyroxine after starting rifampin. Case Report Patient is 78-year-old woman history Papillary Thyroid Cancer (PTC) in remission status post thyroidectomy 1994 and radioactive iodine 1997. had been dose Levothyroxine 75-88mcg daily until visit January 2013 when her TSH was found to be 39 despite compliance levothyroxine. Further revealed that she diagnosed Mycobacterium Avium Intracellulare (MAI) infection the lungs for which given rifampin therapy. Her progressively 150mcg daily. She received 18 months, from August 2012 April 2013. later changed average 139 mcg /day based levels continued same course. In 2014, following discontinuation rifampin, decreased 100mcg subsequently 75mcg During relapse MAI March 2016, dosage similarly again 125mcg 24.58. June 2017, discontinued completion second course treatment, 88 daily, 75 September 64mcg most recently age long-term target mid normal TSH. Discussion used treat active tuberculosis among other uses. It inducer interacts drugs. reported previously cause patients underlying disorder serum while levothyroxine, but its impact function not clearly described. Our thyroidectomy, almost 100% increase started therapy, returning baseline requirements off This highlights severe significant importance close monitoring especially context hypothyroidism. Presentation: No date time listed