Weekly Intramuscular Injection of Levothyroxine following Myxoedema: A Practical Solution to an Old Crisis

Thyroid function and opium use disorder: a cross-sectional study on the Fasa adults cohort study (FACS), 2017

BACKGROUND

Addiction increases the risk of different lifelong disorders. However, there are limited studies evaluating the effects of opioid use disorder (OUD) on thyroid function. The present study aimed to compare the thyroid function of individuals with and without OUD.

METHODS

This cross-sectional study was conducted on 700 eligible participants of the Persian Cohort of Fasa, Iran. Pregnant women and participants with false or missing data were excluded from the study. Remained participants were divided into case and control groups based on the recorded history of OUD. Frozen plasma samples of the cohort bank were used to determine the levels of T3, T4, and thyroid-stimulating hormone (TSH). The thyroid function was compared between the two groups using the Mann-Whitney test (P < 0.05).

RESULTS

The mean age of the final studied population (n = 648) was 54.0 ± 9.8 years, including 336 men (49.1%) and 197 participants with OUD (28.8%). The median levels of TSH, T4, and T3 were 2.91 ± 4.61, 9.26 ± 3.65, and 1.22 ± 0.49, respectively. The case group had significantly higher TSH (3.72 ± 6.2 vs. 2.58 ± 3.75, P < 0.001) and lower T4 (8 ± 3.6 vs. 9.8 ± 3.5, P < 0.001). Also, T3 was slightly lower in the case group (1.1 ± 0.5 vs. 1.3 ± 0.5; P = 0.369), although this association was only significant in female opium users (P < 0.001).

CONCLUSIONS

The present findings revealed that OUD caused a reduction in T4 while increasing TSH. Therefore, OUD may lead to the development of primary hypothyroidism, which needs to be investigated in future studies.

Evaluation of the therapeutic effect of Descurainia sophia (L.) Webb ex Prantl seed extract on hyperthyroidism: A double-blind placebo-controlled pilot clinical trial

The seeds of Descurainia sophia (L.) Webb ex Prantl contain goitrogenic glucosinolates, such as gluconapin (3-butenyl glucosinolate). Because of the important role of iodine in the synthesis of thyroid hormones and the inhibitory activity of D. sophia on iodine uptake by the thyroid gland, this study aimed to determine the effects of D. sophia syrup on clinical and biochemical variables of thyrotoxicosis in hyperthyroid patients. In this randomized, double-blind trial, 10 newly diagnosed hyperthyroid female patients were randomly assigned to treatment with (1) methimazole (MMI) plus D. sophia capsules (350 mg/d) or (2) MMI plus placebo capsules. The primary outcomes were clinical and biochemical manifestations of hyperthyroidism after 60 days. Serum levels of FT3 and FT4 significantly decreased (5.9 ± 2.5 vs. 9.4 ± 5.9 and 29.1 ± 3.1 vs. 31.77 ± 3.7, respectively) and the serum thyroid-stimulating hormone (TSH) concentration significantly increased in the D. sophia group contrasted to the placebo group (4.7 ± 0.1 vs. 0.05 ± 0.02). Significant improvement in the thyrotoxicosis clinical symptoms was reported in the D. sophia group contrasted to the placebo group (p < .05). D. sophia can suppress plasma levels of FT3 and FT4 and may be useful as adjunctive therapy for hyperthyroidism.

Development and validation of a high-performance liquid chromatography method for levothyroxine sodium quantification in plasma for pre-clinical evaluation of long-acting drug delivery systems

Levothyroxine (LEVO) sodium is an FDA-approved drug that is used to treat underactive thyroid (hypothyroidism) and other conditions. It is generally used as a thyroid-stimulating hormone administered orally. However, this approach has some drawbacks such as this drug should be taken every day 30 min to 1 h prior to breakfast with an empty stomach, moreover, some food interactions must be monitored. Thus, alternative innovative approaches capable of providing sustained LEVO release should be developed. Our research was designed to establish a simple quantitative determination method for LEVO in rat plasma for pre-clinical evaluation of long acting formulations using a high-performance liquid chromatography method, to validate the analytical method according to ICH guidelines and to characterise its pharmacokinetic behavior in rats. After simple protein precipitation with acetonitrile, LEVO was eluted on a Xselect CSH™ C18 column (Waters, 3.0 × 150 mm) with a particle size of 3.5 μm using a mobile phase of water and acetonitrile at a ratio of 65 : 35% v/v, including 0.1% v/v of trifluoracetic acid. The calibration standards used for plasma ranged between 0.5-1000 ng mL^-1 with a correlation coefficient (r²) of ≥0.998. The limit of detection was 0.44 ng mL^-1 and the lower limit of quantitation was 1.33 ng mL^-1. The extraction recovery of LEVO in rat plasma samples by this method was between 80 and 85%. The method was selective, sensitive, accurate and precise for detecting and quantifying LEVO in a pharmacokinetic study carried out in rats for pre-clinical evaluation of long acting formulations. The validated HPLC method meets the ICH established requirements and therefore offers a wide range of potential applications in pre-clinical therapeutic drug monitoring, pharmacokinetics and toxicology.

Poly(caprolactone)-based subcutaneous implant for sustained delivery of levothyroxine

This work aimed to develop a subcutaneous implant for prolonged delivery of LEVO to treat hypothyroidism. This could overcome challenges with patient compliance and co-administration and could improve treatment of this condition. For this purpose, implants were produced by solvent casting mixtures of poly(caprolactone) (PCL), poly(ethylene glycol) (PEG) and LEVO sodium. These implants contained mixtures of PCL of differing molecular weight, PEG and different LEVO sodium loadings (20% or 40% w/w). SEM images confirmed that the drug was evenly dispersed throughout the implant. In vitro release rates ranging from 28.37 ± 1.19 - 78.21 ± 19.93 µg/day and 47.39 ± 8.76 - 98.92 ± 4.27 µg/day were achieved for formulations containing 20% and 40% w/w drug loading, respectively. Implants containing higher amounts of low molecular weight PCL and 40% w/w of LEVO showed release profiles governed by zero order kinetics. On the other hand, implants containing higher amounts of high molecular weight PCL showed a release mechanism governed by Fickian diffusion. Finally, two representative formulations were tested in vivo. These implants were capable of providing detectable LEVO levels in plasma during the entire duration of the experiments (4 weeks) with LEVO plasma levels ranging between 5 and 20 ng/mL.

HPLC method for levothyroxine quantification in long-acting drug delivery systems. Validation and evaluation of bovine serum albumin as levothyroxine stabilizer

Deficiency of thyroid hormones (hypothyroidism) is treated with oral levothyroxine (LEVO). However, the effectiveness of oral administration is highly dependent on the co-administration of food and other drugs. This factor, in combination with the chronic nature of this condition, mean that there are concerns with patient compliance. Development of long acting formulations to treat hypothyroidism could potentially solve this problem. However, LEVO instability in solution could be problematic. In order to develop long acting LEVO delivery systems in vitro drug release experiments should be carried out. However, short term LEVO stability in aqueous solution will prevent this. BSA was used as a stabiliser for LEVO; extending the stability of the drug in aqueous solutions from a few hours to 2 weeks. In order to achieve this, the required concentration of the protein was 0.1% w/v. Subsequently, an HPLC method capable of separating LEVO from the protein was developed and validated following ICH guidelines. The analysis was carried out using a reverse phase HPLC method on an Agilent 1220 Infinity II LC system. The column used to achieve separation was a Zorbax Eclipse plus C18 (95 Å pore size, 250 mm length x 4.6 mm internal diameter; 5 μm particle size). The mobile phase used was composed of acetonitrile and 0.1% trifluoroacetic acid at a ratio of 50:50% v/v. UV detection of LEVO sodium was carried out at 225 nm. The retention time for the drug was 6.6 minutes. The method showed a limit of detection of 0.03 μg/mL and a limit of quantification of 0.09 μg/mL. Finally, this method was used to evaluate the release from implants containing 20% w/w of LEVO. These devices were prepared using a solvent casting method with poly(caprolactone) and LEVO. These devices showed an initial burst release over the first 3 days. Subsequently, they were capable of providing a linear release rate over the following 25 days.

Treatment with Intramuscular Levothyroxine in Refractory Hypothyroidism

INTRODUCTION

Orally and daily levothyroxine (LT4) is the treatment of choice for hypothyroidism. In the majority of cases, the lack of effectiveness by this way may be due to poor adherence; however, gastrointestinal malabsorption may explain more cases of thyroxine refractoriness than previously reputed, due to the number of occult forms of these disorders.

CASE PRESENTATION

A 55-year-old white man with a diagnosis of low risk of recurrence of follicular variant of papillary thyroid carcinoma was treated with total thyroidectomy, 30 mCi iodine 131, and oral LT4. A year before he presented a gastric adenocarcinoma that required a partial gastrectomy. He evolved with multiple episodes of intestinal subocclusion that had to be treated with enterectomy in the first instance, then digestive rest and total parenteral nutrition. In spite of having made increases in oral LT4 dose (3 µg/kg), the patient persisted with a thyroid-stimulating hormone level >100 mIU/L. For this reason, we decided to administer intramuscular LT4.

CONCLUSION

Since there are no guidelines or consensus of intramuscular LT4 use, our experience and how we decided the dose and way of administration are presented in this article to contribute to future cases.

Levothyroxine Dose Adjustment to Optimise Therapy Throughout a Patient's Lifetime

Levothyroxine is the standard therapy for patients with hypothyroidism, a condition that affects up to 5% of people worldwide. While levothyroxine therapy has substantially improved the lives of millions of hypothyroid patients since its introduction in 1949, the complexity of maintaining biochemical and clinical euthyroidism in patients undergoing treatment with levothyroxine cannot be underestimated. Initial dosing of levothyroxine can vary greatly and may be based on the amount of residual thyroid function retained by the patient, the body weight or lean body mass of the patient, and thyroid-stimulating hormone levels. As levothyroxine is usually administered over a patient's lifetime, physiological changes throughout life will affect the dose of levothyroxine required to maintain euthyroidism. Furthermore, dose adjustments may need to be made in patients with concomitant medical conditions, in patients taking certain medications, as well as in elderly patients. Patients who have undergone any weight or hormonal changes may require dose adjustments, and the majority of pregnant women require increased doses of levothyroxine. Optimal treatment of hypothyroidism requires a partnership between patient and physician. The physician is tasked with vigilant appraisal of the patient's status based on a thorough clinical and laboratory assessment and appropriate adjustment of their levothyroxine therapy. The patient in turn is tasked with medication adherence and reporting of symptomatology and any changes in their medical situation. The goal is consistent maintenance of euthyroidism, without the patient experiencing the adverse events and negative health consequences of under- or overtreatment.Funding Merck.Plain Language Summary Plain language summary available for this article.

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

A 53-year-old woman was admitted with thyroid storm and severe behavioural problems. She had longstanding bipolar affective disorder. She was psychotic and obstructed in-patient medical management for thyroid storm. She required one-to-one psychiatric nursing and was placed under section 3 of the Mental Health Act meaning she could be detained in hospital for psychiatric treatment for up to 6 months. She underwent a total thyroidectomy. Due to her paranoid mental state, she refused treatment and the administration of thyroid hormone replacement was difficult. Postoperatively, intramuscular levothyroxine was used effectively to stabilise her thyroid function. There are no consensus guidelines on the use of parenteral levothyroxine and intramuscular levothyroxine is rarely used. This case uniquely illustrates its utility with bi-weekly blood tests showing a fast and stable response to intramuscular hormone replacement.