# Nitisinone desensitization protocol, case report of hereditary Tyrosinemia type 1 with successful treatment and outcomes

## TL;DR

A rare case of Tyrosinemia type 1 in an infant is described, including treatment with Nitisinone and a proposed protocol to manage drug-related adverse events.

## Contribution

A desensitization protocol for Nitisinone is proposed for patients experiencing adverse reactions.

## Key findings

- Timely treatment with Nitisinone and dietary restrictions improved clinical outcomes in a Tyrosinemia type 1 case.
- Adverse events from Nitisinone required dose adjustments and a desensitization approach.
- The case highlights the importance of early diagnosis and management in rare metabolic disorders.

## Abstract

The third known case in the country of Tyrosinemia type 1 is presented, a 10-month-old male infant who was referred to the emergency room due to hepatomegaly, compromised liver function, neurological deterioration, and abnormal urinary amino acids findings. Given the persistence of hepatic deterioration and focal hepatic lesions, a high clinical suspicion of Tyrosinemia type 1 was considered, and targeted treatment with Nitisinone and a restrictive diet was initiated, resulting in an appropriate clinical and tests response. However, there was an abrupt discontinuation of the medication without any medical indication, added to the fact that elevated succinylacetone levels were later reviewed, the main diagnosis was confirmed. The medication was continued, but the patient experienced adverse events related to it, requiring multiple dose adjustments provided by the medical team. Tyrosinemia type I is a rare disease and therefore difficult to diagnose, requiring extensive knowledge for timely and accurate treatment. Hence, the importance of acknowledging the management of these adverse events is crucial. The aim of this article is to present a rare clinical case and propose a desensitization protocol for Nitisinone for those cases that present adverse reactions to the medication.