The Stability of TSH, and Thyroid Hormones, in Patients Treated With Tablet, or Liquid Levo-Thyroxine

Abstract

Approximately, 5% of the population is affected by hypothyroidism, mainly women and persons aged more than 60 years. After the diagnosis of hypothyroidism the usual therapy is tablet levothyroxine (L-T4), with a monitoring of the thyroid-stimulating hormone (TSH) level in primary hypothyroidism every 6–8 weeks and L-T4 is adjusted as necessary to reach an euthyroid state. Once TSH is stabilized in the normal range, it is recommended to conduct annual testing in the treated subjects to warrant suitable replacement. More recently advances regarding L-T4 treatment are the introduction of new oral formulations: the liquid solution, and soft gel capsule. The soft gel capsule permits a quick dissolution in the acid gastric pH. The liquid preparation does not require an acid gastric environment. Many pharmacokinetic studies demonstrated a more rapid absorption for the liquid L-T4, or capsule, than with tablet. Many studies have shown that the liquid, or capsule, formulations can overcome the interaction with foods, drugs or malabsorptive conditions, that are able to impair the tablet L-T4 absorption. Lately studies have suggested that liquid L-T4 can permit to maintain more efficiently normal TSH levels in hypothyroid patients in the long-term follow-up, than tablet L-T4, both in patients with malabsorptive states, and in those without malabsorption. Further large, prospective, longitudinal studies are needed to evaluate the stability of TSH, in hypothyroid patients treated with different L-T4 formulations.

Effectiveness and Safety of Levothyroxine Tablets Combined with Iodine-131 in the Treatment of Thyroid Cancer

“…Patients with advanced cancer may be accompanied by symptoms such as dysphagia, dyspnea, hosing, Horner syndrome, shoulder and occipito-ear pain, and local or distal lymph node metastasis [ 12 , 13 ]. Levothyroxine is mainly used for the treatment of hypothyroidism and hyperthyroidism in clinical practice and is available for suppressive therapy after thyroid cancer surgery [ 14 , 15 ]. Iodine-131 is a relatively common drug in clinical practice with a significant effect in the treatment of differentiated thyroid cancer.…”

Congenital Hypothyroidism in Preterm Newborns – The Challenges of Diagnostics and Treatment: A Review

“…The pharmacotherapy with levothyroxine needs to be implemented. With tablet form the dose should be at 10-15 µg/kg/day and the medication should be taken 60 minutes before the breakfast (95,96). In case of choosing the liquid form, the dosage should be the same, if not lower, as the suppression of TSH is higher due to higher absorption (97)(98)(99).…”

Precision Medicine in Autoimmune Thyroiditis and Hypothyroidism

“…-following bariatric surgery or with intestinal malabsorption (Pirola et al, 2013;Fallahi et al, 2017b); -induced by interferent drugs (Fallahi et al, 2014); -in case of typical or atypical CD (Virili et al, 2012;Zubarik et al, 2015;De Carvalho et al, 2018), or LI (Asik et al, 2014;Fallahi et al, 2017c;Fallahi et al, 2019); -who can not swallow the tablets (Pirola et al, 2014). Moreover, both in patients with malabsorptive issues or with no malabsorption, the oral liquid L-T4 is able to maintain more efficiently, than L-T4 tablets, normal TSH values in hypothyroid patients in the long-term follow-up (Antonelli et al, 2021).…”

“…Moreover, both in patients with malabsorptive issues or with no malabsorption, the oral liquid L-T4 is able to maintain more efficiently, than L-T4 tablets, normal TSH values in hypothyroid patients in the long-term follow-up ( Antonelli et al, 2021 ).…”