Self-Reported Allergy to Thyroid Replacement Therapy: A Multicenter Retrospective Chart Review.

Area of Science:

• Endocrinology
• Pharmacology
• Clinical Medicine

Background:

• Thyroid replacement therapy (TRT) is standard for hypothyroidism, with levothyroxine (LT4) being a widely prescribed drug.
• Immediate drug hypersensitivity reactions (DHRs) to TRT are documented but considered rare.
• Understanding patterns of adverse drug reactions (ADRs) is crucial for patient safety and treatment optimization.

Purpose of the Study:

• To investigate the patterns of adverse drug reactions (ADRs) associated with thyroid replacement therapy (TRT).
• To differentiate between immediate drug hypersensitivity reactions (DHRs) and predictable ADRs in patients on TRT.
• To analyze the incidence and characteristics of TRT-related ADRs.

Main Methods:

• Retrospective review of 466 patient medical charts over an 11-year period (2008-2018).
• Patients included had self-reported allergy to TRT.
• ADRs were categorized into immediate DHRs and predictable ADRs.

Main Results:

• Overall incidence of ADRs to TRT was 0.3% in the study cohort.
• Predictable ADRs (57.5%) were more frequent than DHRs (42.5%).
• Common predictable ADRs included palpitations, nausea, and tremor; common DHRs were rash, hives, and pruritus.

Conclusions:

• The majority of self-reported allergies to TRT in this cohort were attributed to predictable ADRs, not immediate DHRs.
• This finding suggests a need to re-evaluate patient-reported allergies to TRT, distinguishing between reaction types.
• Further research may refine diagnostic approaches for TRT hypersensitivity.