1
|
Gottwald-Hostalek U, Kahaly GJ. Optimizing levothyroxine treatment for subclinical hypothyroidism during pregnancy. Curr Med Res Opin 2024; 40:43-49. [PMID: 37897184 DOI: 10.1080/03007995.2023.2276120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 10/24/2023] [Indexed: 10/29/2023]
Abstract
The onset of pregnancy places additional stress of the thyroid gland, which must produce additional thyroid hormones to support the developing foetus. Hypothyroidism, including subclinical hypothyroidism (SCH), may appear de novo at this time, or existing thyroid disease may become more severe. Accordingly, SCH is a relatively common complication of up to about 3% of pregnancies, with higher rates in some areas. There is strong evidence from systematic reviews and meta-analyses that uncontrolled SCH is associated with an increased risk of adverse pregnancy outcomes, including miscarriage, preeclampsia, and gestational diabetes. The evidence base also suggests that treatment with levothyroxine (LT4), optimized to control thyrotropin (TSH) to within its pregnancy-specific reference ranges reduces these risks. Current management guidelines provide a clear framework of intervention with LT4 in pregnant women with SCH, especially where TSH is high or where thyroperoxidase autoantibodies are present. Sub-optimal adherence to LT4 is common: it is important that patients take their LT4 correctly and that treating physicians and/or healthcare professionals manage these patients according to the latest management guidelines. The titration of LT4 is likely to occur within a range of LT4 daily doses between 25 µg and 75 µg for the majority of this population. LT4 is a narrow therapeutic index drug and small variations in dosage may produce a clinically significant change in thyroid status. Newer formulations of LT4, engineered to provide more precise and consistent dosing, and with a broad range of tablet strengths, may facilitate the precise titration of the LT4 dose for these patients.
Collapse
Affiliation(s)
| | - George J Kahaly
- Department of Medicine, Johannes Gutenberg University Medical Center, Mainz, Germany
| |
Collapse
|
2
|
Ge GM, Man KKC, Cheung ECL, Ip P, Leung WC, Kung AWC, Cheung CL, Wong ICK. Levothyroxine Treatment Among Pregnant Women and Risk of Seizure in Children: A Population-Based Cohort Study. Drug Saf 2023; 46:1149-1159. [PMID: 37843760 DOI: 10.1007/s40264-023-01352-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2023] [Indexed: 10/17/2023]
Abstract
INTRODUCTION AND OBJECTIVE The risk of seizure in offspring following prenatal exposure to levothyroxine is not well investigated. This study aimed to evaluate the association between levothyroxine treatment among pregnant women and the risk of seizure in their offspring. METHODS This population-based cohort study included all pregnant women who delivered a live birth between January 2001 to January 2018, with a follow-up to December 2020, using data from the Hong Kong Clinical Data Analysis and Reporting System. Propensity score fine-stratification weighted hazard ratios (wHR) with 95% confidence intervals (CIs) were presented to assess the association between maternal levothyroxine use during pregnancy and seizures in children. RESULTS Among 528,343 included mother-child pairs, 3044 children were prenatally exposed to levothyroxine at any time during the pregnancy period. A significantly increased risk of seizure was observed in children of the prenatally exposed group compared with the prenatally unexposed group (wHR 1.12, 95% CI 1.02-1.22). An increased risk of seizure was observed when comparing the prenatally exposed group with euthyroid mothers who had no history of thyroid-related diagnosis or prescriptions (wHR 1.12, 95% CI 1.02-1.23). However, no significant difference was observed between the prenatally exposed group and those previously exposed to levothyroxine but had stopped during pregnancy (wHR 0.97, 95% CI 0.66-1.44). No significant difference was observed in the sibling-matched analysis either (wHR 1.23, 95% CI 0.76-2.01). CONCLUSION The observed increased risk of seizure in children born from mothers exposed to levothyroxine during pregnancy might be due to residual confounding by maternal thyroid disease. The findings support the current guidelines on the safe use of levothyroxine treatment during pregnancy.
Collapse
Affiliation(s)
- Grace Mengqin Ge
- Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L02-57, 2/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong
| | - Kenneth K C Man
- Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L02-57, 2/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong
- Research Department of Practice and Policy, UCL, School of Pharmacy, London, UK
| | - Edmund C L Cheung
- Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L02-57, 2/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong
| | - Patrick Ip
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Wing Cheong Leung
- Department of Obstetrics and Gynecology, Kwong Wah Hospital, Yau Ma Tei, Hong Kong
| | - Annie W C Kung
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Ching-Lung Cheung
- Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L02-57, 2/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong
| | - Ian C K Wong
- Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L02-57, 2/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong.
- Research Department of Practice and Policy, UCL, School of Pharmacy, London, UK.
- Aston Pharmacy School, Aston University, Birmingham, B4 7ET, UK.
| |
Collapse
|
3
|
Gottwald-Hostalek U, Razvi S. Getting the levothyroxine (LT4) dose right for adults with hypothyroidism: opportunities and challenges in the use of modern LT4 preparations. Curr Med Res Opin 2022; 38:1865-1870. [PMID: 35484983 DOI: 10.1080/03007995.2022.2071059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Lifelong treatment with levothyroxine (LT4) is the mainstay of management for individuals with hypothyroidism. Many hypothyroid patients start LT4 treatment at a low dose (e.g. 25-50 µg), especially the elderly, those with residual thyroid function, those with low body weight, and those with significant (especially cardiac) comorbidities. Almost half of patients on LT4 replacement therapy demonstrate either under- or over-treatment. Many LT4 preparations have relatively large intervals between tablet strengths at the lower end of their dose ranges (providing 25 µg, 50 µg, and 75 µg tablets), which may represent a barrier to achieving the optimum maintenance treatment for some patients. The availability of intermediate tablet strengths of LT4 in the 25-75 µg range may facilitate precise and effective dose titration of LT4 and may also enable convenient maintenance regimens based on a single LT4 tablet daily, to support adherence to therapy.
Collapse
Affiliation(s)
| | - Salman Razvi
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, UK
| |
Collapse
|