Autonomic: Beta blockers

Question 1

Beta blockers compete with ____ for beta receptors

Answer 1

Isoprenaline

Question 2

Non selective beta blockers

Answer 2

• Propranolol
• Nadolol
• Sotalol
• timolol for eye
• Oxprenolol
• pindolol

Question 3

Selective beta 1 Blocker

Answer 3

• Atenolol
• Bisoprolol
• Nebivolol
• Metoprolol
• practolol
• acebutolol

Question 4

Selective Beta 2 blocker

Answer 4

Butoxamine

Question 5

Beta blockers that also block Alpha 1

Answer 5

• Carvedilol
• Labetalol
• Medroxalol
• Bucindolol

Question 6

Compare between lipophilic & Hydrophilic Beta blockers

Answer 6

• Lipophilic Beta blockers are absorbed better in the GIT
• Lipophilic B blocker pass BBB, therefore may cause sedation, depression, nightmares #️⃣ Hydrophilic B blockers dont pass BBB (CNS)
• Lipophilic B blockers have extensive first pass effect thus have shorter duration (4-6 hours) #️⃣ Hydrophilic have less first pass effect and have longer duration (12-24 hours)

Question 7

Examples of lipophilic Beta blockers

Answer 7

• Propranolol
• Metoprolol

Question 8

Examples of Hydrophilic Beta blockers

Answer 8

• Nadolol
• Atenolol

Question 9

Pharmacokinetics (ADME) of Propranolol

Answer 9

Non selective B blocker
* Absorption: completely absorbed in GIT
* Distribution: Lipophilic -> pass BBB (CNS)
* Metabolism: 2/3 undergo liver first pass effect, 1/3 reach systemic circulation
* Excretion: In urine

Question 10

true or false, Propranolol has ISA (intrinsic sympthomimetic Activity)

Answer 10

False, doesnt have ISA

Question 11

enumerate & Describe theraputic uses of Non selective Beta blockers (propranolol, Nadolol, Sotalol, Timolol)

Answer 11

CNS:
* Anti-parkinsonism
* Anti-Anxiety
* Prophylaxis for Migranes

Eye –> using timolol:
* Open angle glaucoma by decreasing aqueous humor -> decrease IOP

Blood pressure:
* Hypertension
* Pheochromocytoma (increased Catecholamines

Blood vessels:
* Acute dissecting Aortic Aneurysm
* Preventing & treating Liver cirrhosis bleeding

Heart:
* Angina pectoris, to reduce Cardiac work & O2 consumption, NOT IN vasospastic (variant) Angina as it worsens condition
* Acute Phase Myocardial Infarction: Anti arrhythmic & reduced Cardiac worl
* Arrhythmia
* Hypertrophic obstructive Cardiomyopathy (reduce IV septal spasm)

Question 12

Pharmacodynamics of Beta blockers

Answer 12

CNS: Anti-anxiety, anti-parkinsonism, prophylaxis for migrane

Eye: reduce IOP by reducing aqueous humor formation (timolol)

Decreases or Cardiac properties

Antiarrhythmic, causes cell membrane stabilization (by blocking sodium channels) through:
* Beta blocking
* Quinidine like action
* Local anesthetic action

BV: unopposed alpha action –> VC

Kidney: decrease renin secretion

Baroreceptor: resets their sensitivity, so reflex bradicardia/ Tachycardia works again

Respiration: Antagonsies bronchodilator effect of adrenaline

Metabolism:
* decrease glucose by blocking Beta 2 in liver (decrease gycogenolysis)
* decrease FFA in plasma
* Decrease renin
* Hyperkalemia

Question 13

side effects of beta blockers

Answer 13

• if lipophilic, may cause sedation, depression & Nightmares
• May cause heart failure or heart block (severe bradycardia)
• Raynaud’s phenomenon
• cold extermities
• numbness & tingling
• perciptation (presence) of acute broncheal asthma attack for asthmetics
• Hypoglycemia
• Atherosclerosis (decrease HDL due to decreased FFA)
• Hyperkalemia
• sudden discontinuation may cause sympathetic Hyperactivity

Question 14

Contraindications of Beta blockers

Answer 14

• Depression
• Varient Angina
• Heart block
• Severe bradycardia
• Not used with Calcium channel blockers verapamil or diltiazem as it decrease cardiac contraction & conduction
• Ryanaud’s phenomenon
• Other peripheral vascular diseases
• Hypotension
• Hypoglycemia
• bronchial asthma

Question 15

Most Beta 1 selective blocker

Answer 15

Nebivolol

Causes Vasodilatation by NO liberation