background: levothyroxine is commonly used in the treatment of patients with hypothyroidism. levothyroxine is often administered in the morning, on an empty stomach, to increase its absorption. however, many patients have trouble for taking levothyroxine in the morning. the aim of this study was to evaluate the effect of changing administration time of levothyroxine from before breakfast to bef...

BACKGROUND Nonadherence to levothyroxine therapy is one cause of persistent hypothyroidism. To distinguish nonadherence from malabsorption, a levothyroxine absorption test is required. Typically, this test measures the serum free thyroxine (FT4) response to 1000 mcg of oral levothyroxine over 4 to 24 hours. Published data indicate that serum levels of FT4 are at or near their peak 2 hours after...

background: statins, such as simvastatin, are the drugs of choice for the treatment of hypercholesterolemia. on the other hand hypercholesterolmia can occur in hypothyroid patients, who receive levothyroxine. there are few clinical case reports in regards to drug interaction between levothyroxine and lovastatin or simvastatin, indicating decreased levothyroxine effects. this study aimed at dete...

CONTEXT Combined infusion of levothyroxine plus liothyronine, as opposed to levothyroxine alone, is the only way of restoring the concentrations of circulating TSH, T4, and T3 as well as those of both T4 and T3 in all tissues of thyroidectomized rats. Considering the substantial differences in thyroid hormone secretion, transport, and metabolism between rats and humans, whether or not combined ...

Background: Statins, such as simvastatin, are the drugs of choice for the treatment of hypercholesterolemia. On the other hand hypercholesterolmia can occur in hypothyroid patients, who receive levothyroxine. There are few clinical case reports in regards to drug interaction between levothyroxine and lovastatin or simvastatin, indicating decreased levothyroxine effects. This study aimed at dete...

CONTEXT Patients treated with levothyroxine typically ingest it in a fasting state to prevent food impairing its absorption. The serum thyrotropin concentration is the therapeutic index of levothyroxine action. OBJECTIVE The study objective was to determine the effect of the timing of levothyroxine administration in relationship to food on serum thyrotropin levels. DESIGN Participants were ...

We report two patients who had taken levothyroxine at the same dose for several years and who had stable thyroid stimulating hormone (TSH) levels, and who developed clinical and biological hyperthyroidism following switch from ritonavir-boosted protease inhibitors (PIs) to dolutegravir-based HAART. Levothyroxine is metabolized by deiodination and glucuronidation and the induction of glucuronida...

An 82-year-old female with known hypothyroidism was admitted to hospital after being found on the floor. On examination, she was unkempt, confused, bradycardic, hypothermic, and barely arousable. Initial biochemistry revealed a thyroid stimulating hormone (TSH) of >100 mU/L and free thyroxine (FT4) level of 1.5 pmol/L which supported a diagnosis of myxoedema coma. She was resuscitated and comme...

INTRODUCTION Medication changes involving levothyroxine-either dose titrations or switching formulations-occur frequently in patients with erratic thyroid-stimulating hormone (TSH) levels and persistent hypothyroid symptoms. We investigated whether switching patients from levothyroxine tablets to a gel cap formulation of levothyroxine might reduce dose adjustments and improve tolerability and e...

BACKGROUND Statins, such as simvastatin, are the drugs of choice for the treatment of hypercholesterolemia. On the other hand hypercholesterolmia can occur in hypothyroid patients, who receive levothyroxine. There are few clinical case reports in regards to drug interaction between levothyroxine and lovastatin or simvastatin, indicating decreased levothyroxine effects. This study aimed at deter...