Adrenergic beta antagonists are medications used to treat high blood pressure, irregular heartbeats, and heart failure by blocking the effects of the hormone adrenaline on the body's beta receptors. Antonyms for this term include adrenergic beta agonists, which are medications that activate the beta receptors and can increase heart rate, dilate bronchial tubes, and lower blood pressure. Other antonyms may include sympathetic stimulants or sympathomimetics, which activate the sympathetic nervous system and can increase heart rate, blood pressure, and respiratory rate. In contrast, sympathetic inhibitors or sympatholytics are medications that decrease sympathetic activity, resulting in effects such as decreased heart rate, blood pressure, and respiratory rate.