Liver injury induced by levothyroxine in a patient with primary hypothyroidism

Hepatic thyroid hormone receptor-β signalling: Mechanisms and recent advancements in the treatment of metabolic dysfunction-associated steatohepatitis

The pharmacotherapy of metabolic dysfunction-associated steatotic liver disease (MASLD) and its progressive form, the metabolic dysfunction-associated steatohepatitis (MASH), remains a hot topic in research and a largely unmet need in clinical practice. As the first approval of a disease-specific drug, resmetirom, was regarded as a milestone for the management of this common liver disease, this comprehensive and updated review aimed to highlight the importance of the hepatic thyroid hormone (TH) receptor (THR)-β signalling for the treatment of MASH, with a special focus on resmetirom. First, the genomic and non-genomic actions of the liver-directed THR-β mediated mechanisms are summarized. THR-β has a key role in hepatic lipid and carbohydrate metabolism; disruption of THR-β signalling leads to dysmetabolism, thus promoting MASLD and possibly its progression to MASH and cirrhosis. In the clinical setting, this is translated into a significant association between primary hypothyroidism and MASLD, as confirmed by recent meta-analyses. An association between MASLD and subclinical intrahepatic hypothyroidism (i.e. a state of relatively low hepatic triiodothyronine concentrations, with circulating TH concentrations within the normal range) is also emerging and under investigation. In line with this, the favourable results of the phase 3 placebo-controlled MAESTRO trials led to the recent conditional approval of resmetirom by the US FDA for treating adults with MASH and moderate-to-advanced fibrosis. This conditional approval of resmetirom opened a new window to the management of this common and burdensome liver disease, thus bringing the global scientific community in front of new perspectives and challenges.

Developing a machine learning-based predictive model for levothyroxine dosage estimation in hypothyroid patients: a retrospective study

Hypothyroidism, a common endocrine disorder, has a high incidence in women and increases with age. Levothyroxine (LT4) is the standard therapy; however, achieving clinical and biochemical euthyroidism is challenging. Therefore, developing an accurate model for predicting LT4 dosage is crucial. This retrospective study aimed to identify factors affecting the daily dose of LT4 and develop a model to estimate the dose of LT4 in hypothyroidism from a cohort of 1,864 patients through a comprehensive analysis of electronic medical records. Univariate analysis was conducted to explore the relationships between clinical and non-clinical variables, including weight, sex, age, body mass index, diastolic blood pressure, comorbidities, food effects, drug-drug interactions, liver function, serum albumin and TSH levels. Among the models tested, the Extra Trees Regressor (ETR) demonstrated the highest predictive accuracy, achieving an R² of 87.37% and the lowest mean absolute error of 9.4 mcg (95% CI: 7.7-11.2) in the test set. Other ensemble models, including Random Forest and Gradient Boosting, also showed strong performance (R² > 80%). Feature importance analysis highlighted BMI (0.516 ± 0.015) as the most influential predictor, followed by comorbidities (0.120 ± 0.010) and age (0.080 ± 0.005). The findings underscore the potential of machine learning in refining LT4 dose estimation by incorporating diverse clinical factors beyond traditional weight-based approaches. The model provides a solid foundation for personalized LT4 dosing, which can enhance treatment precision and reduce the risk of under- or over-medication. Further validation in external cohorts is essential to confirm its clinical applicability.

Propafenone-Induced Cholestatic Liver Injury: When Diagnosis Does Not Skip a Beat

Introduction: Propafenone is a widely used class Ic antiarrhythmic drug that is mainly metabolised by the liver. Hepatotoxicity associated with propafenone is rare, with only a few clinical cases reported in the literature. Case Presentation: We presented a case of propafenone-related hepatotoxicity, with cholestatic liver injury and development of jaundice and pruritus within 3 to 4 weeks of treatment initiation. Three months after discontinuation, the patient was asymptomatic, and all liver tests normalised. Conclusion: With this clinical case, we aimed to emphasise the importance of the medication history and the exclusion of other possible causes of altered liver enzymes.

Liver Stiffness in Obese Hypothyroid Patients Taking Levothyroxine

Background and Objectives: Thyroid dysfunction is associated with non-alcoholic fatty liver disease, but its role in the progression of liver damage in obese patients remains unclear. In addition, several case reports have suggested the existence of a levothyroxine-induced liver injury, which has been poorly investigated. Our aim was to verify whether a difference in the prevalence of liver fibrosis exists in a population of obese individuals taking Levothyroxine. Materials and Methods: We conducted a cross-sectional study on a population of 137 obese individuals, of which 49 were on replacement therapy with Levothyroxine. We excluded those who had hypertriglyceridemia and diabetes mellitus. All participants underwent a liver stiffness assessment by transient elastography as well as biochemical measurements. In subjects with liver fibrosis, other cause of liver fibrosis were ruled out. Results: Participants taking Levothyroxine had a higher prevalence of liver fibrosis than those not taking Levothyroxine (30.6% vs. 2.3%; p < 0.001), and these results were obtained after we made an adjustment for age (Exp(B) = 18.9; 95% CI = 4.1−87.4; p < 0.001). The liver stiffness value differed significantly between groups (6.0 ± 3.6 and 5.1 ± 1.2, p = 0.033). Of those subjects taking Levothyroxine, there were no significant differences in the dose of medication (1.21 ± 0.36 vs. 1.07 ± 0.42; p = 0.240) and treatment duration (13.7 ± 7.43 vs. 11.13 ± 6.23; p = 0.380) between those with and without liver fibrosis. Conclusions: We found, for the first time, a greater prevalence of liver fibrosis in obese individuals taking Levothyroxine than in those not taking this medication. This finding needs to be confirmed by longitudinal population studies as well as by cellular studies.

Levothyroxine sodium pentahydrate tablets - formulation considerations

Even though levothyroxine sodium pentahydrate tablets have been in the market since 1955, there continue to be recalls due to sub potency. We have comprehensively reviewed the factors affecting its stability in solid oral dosage forms. A compilation of marketed formulation compositions enabled the identification of the potential 'problem excipients'. Two excipient properties, hygroscopicity and microenvironmental acidity, appeared to be responsible for inducing drug instability. In drug products, depending on the formulation composition and storage conditions, the pentahydrate can dehydrate to highly reactive levothyroxine sodium monohydrate, or undergo salt disproportionation to the free acid form of the drug. The USP assay method (HPLC based) is insensitive to these different physical forms of the drug. The influence of physical form of levothyroxine on its chemical stability is incompletely understood. The USP has five product-specific dissolution tests reflecting the complexity in its evaluation.

Levothyroxine-induced liver injury followed by complete recovery upon cessation of the drug: a case report

Background

Levothyroxine is a synthetic thyroxine and is the treatment of choice for hypothyroidism. It is a prohormone with minimal intrinsic activity. The drug is de-iodinated in peripheral tissue to form triiodothyronine, which is the active thyroid hormone. On initiation of treatment, levothyroxine is titrated, and usually it is extremely well tolerated in the vast majority of patients. We report a case of a patient with self-limiting levothyroxine-induced liver injury, a rare adverse effect of this drug.

Case presentation

We report a case of a 34-year-old Mediterranean woman diagnosed with post-thyroidectomy hypothyroidism. She was commenced on levothyroxine and developed liver injury confirmed by noninvasive liver investigations. Complete recovery of the patient’s liver tests occurred upon cessation of the drug. Triiodothyronine was an appropriate treatment alternative.

Conclusion

Levothyroxine-induced liver injury is a rare, and in the present case report, a self-limiting, adverse effect. The diagnosis of our patient was confirmed via noninvasive diagnostic methods. Knowledge of this rare adverse effect is important in the differential diagnosis of patients who have commenced on levothyroxine and have deranged liver enzymes in the context of hypothyroidism.

Liver dysfunction induced by Levothyroxine Sodium Tablets (Euthyrox®) in a hypothyroid patient with Hashimoto's thyroiditis: case report and literature review

A 49-year-old woman with hypothyroidism developed liver dysfunction after increasing dose of levothyroxine (L-T4) (Euthyrox^®) from 25 μg to 50 μg. Viral hepatitis, autoimmune hepatitis and non-alcoholic steatohepatitis (NASH) were ruled out with examinations. She had no concurrent medication and had no history of infectious, chronic or any other autoimmune diseases. After cessation of Levothyroxine Sodium Tablets (Euthyrox^®), liver enzymes gradually returned to normal. She was diagnosed levothyroxine-induced liver injury, based on criteria proposed in "Diagnosis and treatment guideline on drug-induced liver injury" issued by the Chinese Medical Association (2015). As an alternative 25 μg qod of Levothyroxine Sodium Tablets (Letrox^®) was tried and increased gradually up to 75 μg daily. Since then liver enzymes have remained within normal range. The main difference of additive for both tablets is whether it contains lactose or not: Euthyrox^® contains lactose which caused no liver injury, thus excluding the possibility that an additive of Euthyrox^® contributed to liver injury. The relatively quicker and larger replacement with synthetic T4 for hypothyroidism inducing transient thyrotoxicosis was suspected, although thyroid function was normal. Immune-mediated drug-induced liver injury (DILI) was also not excluded. This is a rare case of drug-induced liver injury due to levothyroxine tablets. It reminded us that when replacement with synthetic T4 for hypothyroidism is done, smaller-dose initiation and slower-speed increase may be useful for treatment of cases similar to genetically susceptible individuals.

Drug-induced lymphocyte stimulation test in the prediction of drug-induced hypersensitivity to antituberculosis drugs

Antituberculosis (TB) chemotherapeutic drugs may cause a variety of adverse drug reactions (ADRs). To assess the potential of drug-induced lymphocyte stimulation test (DLST) in screening ADRs in patients treated with anti-TB drugs, we performed DLST in 272 TB patients (176 cases with ADRs and 96 controls without ADRs) treated with anti-TB drugs isoniazid (INH), rifampicin (RFP), ethambutol (EMB), and pyrazinamide (PZA). The ADRs were diagnosed by drug provocation test based on clinical and laboratory examinations. The sensitivities of DLST in the diagnosis of INH-, RFP-, EMB-, or PZA-induced ADRs were 57.8%, 37.1%, 42.4%, and 23.1%, respectively, with the corresponding specificities being 93.4%, 94.0%, 97.5%, and 98.8%. DLST has high specificity and limited sensitivity in the diagnosis of anti-TB drug-induced ADRs. In combination with clinical observation and drug use history, DLST could have a predictive validity of ADRs, especially when a positive result is obtained.

Occurrence of thyroxine tablet (Thyradin S(®)) - induced liver dysfunction in a patient with subclinical hypothyroidism

A 54-year-old woman with subclinical hypothyroidism developed liver dysfunction after increasing dose of levothyroxine (L-T4) in tablet form (Thyradin S(®)) from 25μg to 50μg. Viral hepatitis, autoimmune hepatitis and NASH were ruled out with examinations. After cessation of levothyroxine in 50μg tablet form, liver enzymes gradually returned to normal. She was diagnosed levothyroxine-induced liver injury, based on criteria proposed in DDW-J 2004 workshop. Thyradin S(®) powder 0.01% (here in after referred to as L-T4 in powder form) was tried as an alternative, and liver enzymes have remained within normal range. As for Thyradin S(®) tablet, additives are different for each type of levothyroxine sodium content. The difference of additive is whether Fe2O3 is contained or not: it is not included in Thyradin S(®) 50μg tablet and powder form. Although there are two case reports in the Japanese literature and three case reports in the English literature of liver dysfunction suspected due to L-T4, we cannot find past reports about cases of drug induced liver dysfunction due to Fe2O3 free levothyroxine tablet form. This is a rare case report of drug induced liver injury due to Fe2O3 free levothyroxine tablet form, and administration of L-T4 in powder form may be useful for treatment of cases similar to this one.

Practical guidelines for diagnosis and early management of drug-induced liver injury

The spectrum of drug-induced liver injury (DILI) is both diverse and complex. The first step in diagnosis is a suspicion of DILI based on careful consideration of recent comprehensive reports on the disease. There are some situations in which the suspicion of DILI is particularly strong. Exclusion of other possible etiologies according to the pattern of liver injury is essential for the diagnosis. In patients with suspected DILI, diagnostic scales, such as the Councils for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method (CIOMS/RUCAM) scale, may be helpful for the final diagnosis. Early management of DILI involves prompt withdrawal of the drug suspected of being responsible, according to serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and total bilirubin (T-Bil). However, as DILI patients may show resolution of liver injury without discontinuation of the drug, it should be carefully evaluated whether the suspected drug should be discontinued immediately with adequate consideration of the importance of the medication.

Practical guidelines for diagnosis and early management of drug-induced liver injury

The spectrum of drug-induced liver injury (DILI) is both diverse and complex. The first step in diagnosis is a suspicion of DILI based on careful consideration of recent comprehensive reports on the disease. There are some situations in which the suspicion of DILI is particularly strong. Exclusion of other possible etiologies according to the pattern of liver injury is essential for the diagnosis. In patients with suspected DILI, diagnostic scales, such as the Councils for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method (CIOMS/RUCAM) scale, may be helpful for the final diagnosis. Early management of DILI involves prompt withdrawal of the drug suspected of being responsible, according to serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and total bilirubin (T-Bil). However, as DILI patients may show resolution of liver injury without discontinuation of the drug, it should be carefully evaluated whether the suspected drug should be discontinued immediately with adequate consideration of the importance of the medication.

Practical guidelines for diagnosis and early management of drug-induced liver injury

The spectrum of drug-induced liver injury (DILI) is both diverse and complex. The first step in diagnosis is a suspicion of DILI based on careful consideration of recent comprehensive reports on the disease. There are some situations in which the suspicion of DILI is particularly strong. Exclusion of other possible etiologies according to the pattern of liver injury is essential for the diagnosis. In patients with suspected DILI, diagnostic scales, such as the Councils for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method (CIOMS/RUCAM) scale, may be helpful for the final diagnosis. Early management of DILI involves prompt withdrawal of the drug suspected of being responsible, according to serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and total bilirubin (T-Bil). However, as DILI patients may show resolution of liver injury without discontinuation of the drug, it should be carefully evaluated whether the suspected drug should be discontinued immediately with adequate consideration of the importance of the medication.

Drug-induced liver injury in 2007

PURPOSE OF REVIEW

To summarize the pertinent literature on the causes, epidemiology, prevalence, clinical features, evaluation and mechanisms of drug-induced liver injury reported during 2007.

RECENT FINDINGS

Although the frequency of drug-induced liver injury remains low, new data from the Centers for Disease Control and Prevention confirm that of the approximately 1600 new acute liver failure cases annually, acetaminophen hepatotoxicity accounts for 41%; among children with acute liver failure, acetaminophen was the second most common cause. Antimicrobials lead the list of non-acetaminophen causes of drug-induced liver injury. In Asia, herbal compounds are the most common causes of the condition. Pravastatin was shown to be safe in patients with nonalcoholic fatty liver disease or chronic hepatitis C. The US Food and Drug Administration issued a draft guidance document on the premarketing clinical evaluation and stopping rules of drug-induced liver injury signals, including Hy's Law cases in clinical trials.

SUMMARY

The year 2007 brought with it several reminders of the importance of drug-induced liver injury in the clinical trial as well as the clinical practice setting. There is additional evidence that statin drugs may be used safely in patients with chronic liver disease. Comments received by the US Food and Drug Administration to finalize their guidance document are eagerly awaited.