Naslov
Propranolol Use in Hyperthyreoidsm

Autori
Baretić, Maja

Vrsta, podvrsta i kategorija rada
Poglavlja u knjigama, stručni

Knjiga
Propranolol: Medical Uses, Mechanisms of Action and Potential Adverse Effects

Urednik/ci
Puljević, Mislav

Izdavač
Nova Science Publishers

Grad
New York (NY)

Godina
2015

Raspon stranica
75-86

ISBN
978-1-63483-004-1

Ključne riječi
Propranolol, Hyperthyreoidism, Therapy

Sažetak
Hyperthyroidism is the principal endocrine indication for propranolol treatment. High level of thyroid hormones result in a hyperdynamic cardiovascular state including increased stroke volume, augmented myocardial contractility and an growth of the left ventricle. Thyroid hormones have a direct effect on the cardiovascular system. They increase cardiac output and lower systemic vascular resistance ; also amplify intrinsic activity of sinoatrial node. Such actions lead to increased heart rate with a higher chance of supraventricular tachyarrhythmia, and the most common of them is atrial fibrillation. Thyroid hormones have positive chronotropic and dromotropic activity. Hyperthyroidism creates higher sensitivity to sympathetic stimulation which is conducted through greater number of β- adrenergic receptors. Myocytes contain an enzyme calle type 2 deiodinase which increases local conversion T4 to T3. As a non-selective inhibitor of β-adrenergic receptors, propranolol is ideal for treating hyperthyroidism. By blocking β 1 receptors affects the sinoatrial and AV nodes propranolol lowers heart frequency, weakens myocardial contractions and leads to lower oxygen demand. By influencing β 2 receptors peripheral vasoconstriction rises. Thyroid hormone impact on β 2 receptors changes the activity of the peripheral 5’-monodeiodinase which converts T4 on the periphery in the active forms of T3. By using propranolol the tremor is reduced. Since the drug is lipophilic it crosses the blood– brain barrier influencing central nervous system. With propranolol in hyperthyroidism there is less emotional lability and mental tension. The amount of the drug is 10-40 mg divided into 3-4 doses a day, and maximal dosage is 160 mg.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

POVEZANOST RADA