Definition of fatalism for English Language Learners : the belief that what will happen has already been decided and cannot be changed Learn More about fatalism
The receptors most relevant to the pharmacology of vasopressors are adrenoceptors. Adrenoceptors, sometimes referred to as adrenergic receptors, interact with norepinephrine, epinephrine, and chemically similar drugs (called adrenomimetic, adrenergic, or sympathomimetic agents).
Beta-blockers are drugs that bind to beta-adrenoceptors and thereby block the binding of norepinephrine and epinephrine to these receptors. This inhibits normal sympathetic effects that act through these receptors. Therefore, beta-blockers are sympatholytic drugs. Some beta-blockers, when they bind to the beta-adrenoceptor, partially activate the receptor while preventing norepinephrine from binding to the receptor. These partial agonists therefore provide some background of sympathetic activity while preventing normal and enhanced sympathetic activity.