Desensibilización a levotiroxina. Caso clínico

Abstract

We report a 39-year-old female who underwent a total thyroidectomy as treatment for a thyroid papillary cancer. She suffered several episodes of mild angioedema in lips and tongue, after using different commercial Levothyroxine formulations, with and without excipients. Given the need to use this drug, the patient was admitted in our hospital and we proceeded to desensitize her with oral Levothyroxine. The patient fasted throughout the whole procedure, was properly monitored and had an adequate peripheral venous access. On the first day of the procedure, a 15-step protocol was performed, first administering placebo and then, compounded formulations of Levothyroxine starting from 0.01 ug, followed by doubling doses every 15 minutes until the cumulative dose of 111.95 ug was completed, corresponding to the daily dose of Levothyroxine her endocrinologist prescribed (112 ug). The patient was monitored at baseline, between each dose and up to 3 hours after the procedure was completed. There were no incidents such as urticaria, angioedema, or others. On the second day, the patient received a single-full dose of 112 ug on an empty stomach. The medication was successfully tolerated and she was discharged. Thereafter, she tolerates daily Levothyroxine.

Practical Application of Levothyroxine-Based Therapy

“…Additionally, as with any medicinal product, hypersensitivity reactions in the skin or respiratory system may occur rarely in response to components of the LT4 tablet, possibly including LT4 itself [1,2]. Such reactions tend to manifest with symptoms, such as urticaria, eczema-like rashes, fever and disturbances of liver function tests, and may persist when different LT4 products are prescribed [10][11][12][13]. Excipients vary somewhat between LT4 preparations, and so changes the brand of LT4 may help to resolve the issue; however, hypersensitivity to LT4 itself may effectively prevent the effective management of hypothyroidism [14].…”

“…Procedures for oral desensitisation have been described, where administration of successively increasing LT4 dosages (e.g. at 30-min intervals, from an initial dose as low as 0.01 μg) enable subsequent chronic therapy with doses of LT4 that are clinically effective [10][11][12][13].…”

A Bizarre Complication of Levothyroxine Therapy

“…Drug desensitization under supervision with gradual uptitration of the dose may be done as a treatment option in patients who develop recurrent allergic reactions to different brands of thyroxine. [ 6 ]…”