Intramuscular levothyroxine: a solution to a mental health related thyroid crisis

Levothyroxine: Conventional and novel drug delivery formulations

Despite the fact that levothyroxine is one of the most prescribed medications in the world, its bioavailability has been reported to be impaired by many factors, including interfering drugs or foods and concomitant diseases, and persistent hypothyroidism with a high dose of levothyroxine is thus elicited. Persistent hypothyroidism can also be induced by noninterchangeability between formulations and poor compliance. To address these issues, some strategies have been developed. Novel formulations (liquid solutions and soft-gel capsules) have been designed to eliminate malabsorption. Some other delivery routes (injections, suppositories, sprays, and sublingual and transdermal administrations) are aimed at circumventing different difficulties in dosing, such as thyroid emergencies and dysphagia. Moreover, nanomaterials have been used to develop delivery systems for the sustained release of levothyroxine to improve patient compliance and reduce costs. Some delivery systems encapsulating nanoparticles show promising release profiles. In this review, we first summarize the medical conditions that interfere with the bioavailability of oral levothyroxine and discuss the underlying mechanisms and treatments. The efficacy of liquid solutions and soft-gel capsules are systematically evaluated. We further summarize the novel delivery routes for levothyroxine and their possible applications. Nanomaterials in the levothyroxine field are then discussed and compared based on their load and release profile. We hope the article provides novel insights into the drug delivery of levothyroxine.

Weekly Versus Daily Levothyroxine Tablet Replacement in Adults with Hypothyroidism: A Meta-Analysis

Objectives

Daily levothyroxine is the treatment of choice and standard of care in hypothyroidism, sufficient to restore thyroid stimulating hormone (TSH) to normal range. For many patients, daily lifelong therapy is required, making adherence a major issue. In such cases, weekly replacement may be a suitable alternative to improve adherence. In this study, we aimed to determine the efficacy and safety of weekly levothyroxine replacement among adults with hypothyroidism.

Methodology

Electronic databases were searched. Two reviewers (HCC and RBL) independently screened the abstracts, reviewed full-text papers, critically appraised the quality of included studies using PRISMA guidelines. Meta-analysis was performed using the random-effects model. The primary outcome is the difference in serum TSH levels between weekly and daily administration, while secondary outcomes included adverse events and symptoms of hypothyroidism.

Results

The primary outcome is the difference in serum TSH levels between weekly and daily administration. Secondary outcomes included adverse events and clinical symptoms. The study included two randomized trials (n=109) in the primary analysis. The difference in TSH levels was 1.78 mIU/mL higher [(95% confidence interval (CI): 1.28 to 2.28, p<0.00001] at 6 weeks and 1.22 mIU/mL higher (95% CI: 0.76 to 1.67, p<0.00001) at 12 weeks for the weekly regimen. There was no significant heterogeneity between the two groups. There was no significant difference in hypothyroid symptoms and adverse events before and after levothyroxine treatment within each group.

Conclusions

Weekly levothyroxine resulted in less suppression and higher mean serum TSH levels, while still remaining within the normal reference range. It may be a suitable alternative for non-adherent patients. However, larger randomized trials with longer duration of follow-up are needed to firmly establish its role.

Management of endocrine conditions at the end of life

An important facet to end-of-life care is deprescribing. This can be challenging when reviewing life-sustaining endocrine medications but, unlike for diabetes, there is no national guidance to support patients and clinicians faced with care planning. This article reviews the limited current evidence to highlight areas for further discussion and research with the aim of moving towards consensus opinion. Discontinuation of certain endocrine medications, including corticosteroids, desmopressin and levothyroxine, is likely to precipitate an 'endocrine-driven mechanism of death', while it may be reasonable to discontinue other endocrine medications without the risk of hastening death or causing unnecessary symptoms. However, the over-arching theme should be that early discussion with patients regarding conversion or discontinuation of endocrine medications or monitoring is central to care planning.