ADRENORECEPTOR AGONISTS Flashcards
pheochromocytomas are uncommon tumors, not malignant, but produce lots of norepinephrine and epinephrine. they can cause extreme hypertension, what symptoms would you expect? How would you treat patient?
PCT are tumors that release high amounts of epinephrine and norepinephrine, which is the same hormones that are released when you are nervous or frightened. Symptoms of epinephrine an NE release are clammy hands, anxiety, feeling of doom, tachycardia, sweating and increased blood pressure. PCT’s have a much more pronounced effect, and can cause feelings of fright and impending doom. sweating is because the sweat glands on your hands and. arm pits are innervated with adrenergic neurons.
increased release of E and NE increase blood pressure, and patients with PCT also develop diabetes due to inhibition of gluconeogenesis.
TREATMENT - block alpha adrenergic receptors before surgery to bring down the blood pressure. BB shouldnt be given until all alpha adrenergic receptors have been completely blocked, because blocking beta receptors will cause a marked increase in BP (beta agonism leads to vasodilation).
what is mechanism of anaphylaxis? what are the treatments for anaphylaxis, and how do the agents work?
anaphylaxis is mediated by factors released by the degranulation of mast cells and basophils when stimulated by IgE antibodies.
cause vasodilation, and bronchoconstriction leading to decreased blood pressure (shock) and the bronchoconstriction an leakage of fluid leads to edema, which can lead to obstruction of the airways. Epinephrine (treatment) decreases these effects (decreases the drop in BP, decreases bronchoconstriction, and decreases edema). anaphylaxis can reoccur after treatment with epinephrine because its half life is short, antihistamines can be used and prevent the binding of histamine to the receptor which isnt the major factor leading to shock. corticosteroids can be used but effects are slow in onset and arent used for acute treatment.
