:L-17 Adrenergic Antagonists and Their Functions

Drugs that block the effects of norepinephrine and epinephrine by binding to adrenergic receptors.

Drugs that bind to and block α-adrenergic receptors, reducing the effects of norepinephrine and epinephrine.

Drugs that bind to and block β-adrenergic receptors, reducing the effects of norepinephrine and epinephrine.

These drugs prevent or reverse the actions of norepinephrine and epinephrine, either naturally released or given as medication.

Adrenergic antagonists can be used to treat conditions like high blood pressure, heart disease, anxiety, and migraines.

Propranolol is a nonselective beta-blocker that blocks both β1 and β2 receptors with equal affinity. It is a commonly used example of this type of drug.

By blocking β1 receptors in the heart, propranolol reduces heart rate and force of contraction, leading to a decrease in cardiac output and blood pressure.

Propranolol acts on β1 receptors in the heart, lowering cardiac output, workload, and oxygen consumption. This makes it useful in managing angina.

Propranolol slows down the transmission of electrical impulses in the AV node, affecting the rhythm of the heart.

Propranolol blocks β2 receptors involved in vasodilation, leading to vasoconstriction. This contributes to its effect on blood pressure.

Propranolol can cause bronchoconstriction by blocking β2 receptors in the bronchioles. This can be dangerous for patients with asthma or COPD.

Propranolol can mask the symptoms of hypoglycemia by preventing the normal increase in heart rate and sweating associated with low blood sugar.

Because of its potential side effects, selective β1 blockers have been developed to target heart issues without affecting other tissues.

Propranolol can decrease insulin secretion, leading to higher blood sugar levels in people with type 2 diabetes.

Propranolol can cause a decrease in glycogen breakdown, leading to reduced glucose release into the bloodstream.

Propranolol can lower heart rate and decrease the force of heart contractions, reducing the heart's oxygen demand.

Propranolol can reduce the size of a heart attack and the risk of sudden death after a heart attack.

Propranolol helps control symptoms of hyperthyroidism by slowing down the heart rate and reducing tremor.

Propranolol's ability to enter the brain allows it to treat tremors by acting on the central nervous system.

Propranolol can be used to prevent migraines by reducing the frequency and intensity of headaches.

Propranolol reduces the pressure in the veins leading to the liver, helping to prevent bleeding from varices.

A short-acting β1-selective blocker rapidly hydrolyzed by plasma esterases. It is particularly useful in unstable patients needing β-blockade.

A long-acting β1-selective blocker used for open-angle glaucoma and hypertension.

A once-daily β1-selective blocker with added vasodilatory effects due to nitric oxide release.

A β1-selective blocker with partial agonist activity, meaning it also has some stimulating effect.

A β1-selective blocker useful in angina, hypertension, heart failure, and preventing tachycardias during surgery.

β1-selective blockers may reduce mortality in patients with severe heart failure.

β1-selective blockers, especially at higher doses, can block β2-receptors, which can lead to bronchospasm and problems with breathing.

β-blockers are classified as Class II antiarrhythmic agents. They help regulate heart rhythm and slow down heart rate.

A type of β-blocker with partial agonist activity, meaning it can also activate the receptor to a limited extent. It's helpful for patients with asthma or COPD who need β-blocker therapy, as it can minimize bronchoconstriction.

Another β-blocker with partial agonist activity. Comparable to Pindolol in therapeutic uses but considered stronger.

A nonselective β-blocker without intrinsic sympathomimetic activity. It lowers eye pressure by inhibiting aqueous humor production, making it effective for treating glaucoma.

It's a nonselective β-blocker with the unique property of being absorbed into the bloodstream after eye drops application. This can lead to systemic side effects, such as affecting heart function.

A nonselective β-blocker, known for its potency and long-lasting effect. It's similar to Propranolol, but with a longer duration and fewer side effects on the nervous system.

A combination of drugs that are used together to treat high blood pressure.

A combination of β-blockers and other drugs like diuretics is a common approach to manage high blood pressure. This is where β-blockers come in, effectively managing the heart's workload and reducing blood pressure.

A type of beta blocker that selectively blocks beta-1 receptors in the heart, slowing heart rate and decreasing blood pressure. It's often used to treat high blood pressure, chest pain, and irregular heartbeats. This drug is also preferred in individuals with diabetes or vascular issues due to its selective action.

Another selective beta-1 blocker used to control heart rate and blood pressure. Often prescribed for conditions like high blood pressure, heart failure, and certain arrhythmias.

Beta-blockers, including propranolol, work by blocking the action of adrenaline and noradrenaline (epinephrine and norepinephrine). This reduces the signaling through beta receptors, which are found in the heart, lungs, and other organs. The result is a slower heart rate, decreased blood pressure, and reduced stress on the heart.

Atenolol and metoprolol are often preferred for individuals with diabetes or peripheral vascular disease because they have a higher selectivity for beta-1 receptors found in the heart. This means they are less likely to affect other organs that also have beta receptors, like the lungs.

While similar in function, metoprolol is more commonly prescribed for patients experiencing cold hands and feet. This is because its limited entry into the central nervous system (CNS) reduces the risk of side effects associated with CNS activity.

Beta blockers, like propranolol, help manage congestive heart failure by reducing stress on the heart and decreasing its remodeling process, leading to better function.

Beta blockers like propranolol are effective in managing angina pectoris by reducing the heart's oxygen demand, preventing chest pain during exertion.

Beta-blockers are used to reduce the risk of heart complications after a heart attack. They also play a role in preventing additional heart attacks by stabilizing the heartbeat and reducing blood pressure.