Lesson 4- Lesson 4A- FLUID AND ELECTROLYTES, ADRENERGIC BLOCKERS, ANTIHYPERTENSIVE AGENTS and ANTICOAGULANTS and Lesson 4B- Lesson 4B- SHOCK, ADRENERGIC AGENTS, ANTICOAGULANTS, AND FLUID AND ELECTROLYTES

What body system is regulated by sodium?

CNS

What body system is regulated by potassium?

cardiac

What body system is regulated by calcium?

neuro/nerves

What body system is regulated by magnesium?

neuro/nerves

What are 2 conditions change how adrenergic agents act in the body?

1. Hyperthyroidism- causes the receptors on the blood vessels and muscles to be more sensitive to epinephrine

2. Cocaine use- prevents catecholamines (epinephrine) from Reuptake into vesicles

what are some uses of epinephrine? (5)

1. Vasoconstriction (A1)

   1. Delays absorption of anesthetics

   2. Control superficial bleeding

   3. Elevate blood pressure

2. Mydriasis- pupil dilation (A1)

3. Restore cardiac function during arrest/asystole (B1)

4. Bronchodilaiton in asthma (B2)

5. Anaphylactic shock (A&B)

what are some adverse reactions to epinephrine?

• hypertensive crisis- excessive blood pressure

• Dysrhythmias

• Angina pectoris

• Hyperglycemia

what does ephedrine do? What receptors does it activate?

• pressor effect that lasts 10x longer than epinephrine

• Functions:

  • Peripheral vasoconstrictor

  • increases cardiac output

  • Dilates bronchi

• Adverse effects- hypertension

• Activates alpha and beta receptors

what are some other adrenergic agents?

• amphetamines

• Isoproterenol

• Dobutamine

• Phenylephrine

• Pseudoephedrine

what does dopamine do (@low dose, @moderate dose, @high dose)? What receptors does it activate?

• low dose- increases renal perfusion- B1

• Moderate dose- increases HR and BP in shock- A1

  • HR should not exceed much above 110bpm

• High dose- maintain BP after a code- A1

how do we recognize bronchodilators/B2 agonists?

”-terol”

What drugs are used to treat shock? (4 typically, 4 if needed)

1. Blood/Colloids/Crystalloids

2. Oxygen

3. Vasopressors

   1. Dopamine

   2. Epinephrine

   3. Norepinephrine

   4. Phenylephrine

4. Inotropic Agents

   1. Digoxin

   2. Dobutamine

5. Antibiotics (if needed)

6. Corticosteroids (if needed)

7. Antihistamines (if needed)

8. Bronchodilators (if needed)

what are some adverse reactions of alpha 1 adrenergic agonists?

• sensitivity to light

• Hypertension

• Excessive vasoconstriction can cause tissue death

• Bradycardia

what are some adverse reactions of alpha 2 adrenergic agonists?

• headache

• Dry mouth/nose

• Altered taste

• Conjunctivitis

• Pruritus

what are some adverse reactions of beta 1 adrenergic agonists?

• tachycardia

• Chest pain

• Dysrhythmias of the heart

what are some adverse reactions of beta 2 adrenergic agonists?

• hyperglycemia

• Tremors

what are some adverse reactions of beta 3 adrenergic agonists?

potential of releasing stored chemicals

What do alpha 1 blockers do?

1. Prevents dilation of the pupil

2. Dilates arterioles on skin, mucus membranes, and viscera

3. Dilates veins

4. Decrease peripheral resistance → decreases BP

5. Relax bladder neck and prostatic capsule

what are some adverse reactions to alpha 1 blockers?

• Orthostatic hypotension

• Some reflex tachycardia

• Nasal congestion- distention of nasal veins

• Impotence- inhibition of ejaculation

What are some adverse reactions of alpha 2 blockers?

Can increase reflex tachycardia

What are the drugs that are the non-selective alpha blockers?

• phentolamine

• Phenoxybenzamine

what are some uses of alpha blockers?

1. HTN

2. BPH

3. pheochromocytoma

4. Block catacholamine infiltration

5. Raynaud’s disease

What drugs are alpha 1 selective blockers? How are they identified?

“-zosin”

• doxazosin

• Prazosin

• Terazosin

• Tamsulosin

what are the indications for alpha 1 selective blockers? (2)

1. HTN

2. BPH

What are the therapeutic effects of beta 1 blockers? (3)

Cardioselective

• decrease heart rate

• Decrease contraction of heart AKA cardiac output

• Blocks kidney from releasing renin

What are the therapeutic effects of beta 2 blockers? (3)

predominant effects on bronchials and vascular smooth muscle

• Bronchoconstriction

• Vasodilation

• Decrease glycogenolysis and glucagon secretion (hypoglycemia without normal response of tachycardia)

what are the beta blockers indicated for?

• HTN

• Angina pectoris

• Cardiac dysrhythmias

• MI

• HF

• Hyperthyroidism

• Migraine

• Stage fright

• Pheochromocytoma

• Glaucoma

• useful for ischemic conditions-

  • ischemia to blockade of artery

  • angina to myocardial infarction- narrowed coronary arteries

  • TIA- carotid/brain arteries narrowed

  • Raynaud’s disease

how are beta blockers recognized?

“-olol”

what are some adverse reactions to beta blockers?

• bradycardia

• AV heart block

• HF

• Rebound cardia excitation

• Bronchoconstriction

• Inhibition of glycogenolysis- use with caution in diabetes pts

  • Masks hypoglycemia

• CNS effects- depression, insomnia, nightmares, hallucinations

What are some adverse reactions of centrally acting alpha 2 agonists?

• drowsiness ← CNS depression

• Xerostomia ← dry mouth ← decreases in about 4 weeks

• Rebounding HTN

How do calcium channel blockers work?

Block the movement of calcium into vascular smooth muscle and the myocardium

how are calcium channel blockers identified?

”-dipine”

Ex. Amlodipine, nifedipine, nicardipine, AND verapamil

How does the renin-angiotensin-aldosterone system work?

1. Renin secreted by kidney

2. Liver releases angiotensin I

3. Angiotensin I is converted to angiotensin II in the presence of ACE (angiotensin converting enzyme)

4. Aldosterone can be secreted from angiotensin II

what does angiotensin II cause? (4)

1. Vasoconstriction

2. Release of aldosterone

3. Increases blood pressure

4. Increases blood volume

What does aldosterone cause?

sodium and water retention

What is the therapeutic action (3) and effects (2) of ACE inhibitors?

• Angiotensin remains inactive if the converting enzyme can not work

• Angiotensin II is not formed

• Prevent breakdown of bradykinins and other prostaglandin vasodilators

• Effects of ^^^:

  • Less vasoconstriction

  • Less aldosterone (less sodium and water retained by the body)

how are ACE inhibitors identified?

”-pril”

Ex.

• Captopril (Capoten)

  • Short half-life

• Lisinopril (Prinivil & Zestril)

• Enalapril (Vasotec)

  • Available orally and IV

  • Short half-life

• Benazepril (Lotensin)

• Fosinopril (Monopril)

• Moexiril (Univasc)

• Perindopril (Aceon)

• Quinapril (Accupril)

• Ramipril (Altace)

• Trandolapril (Mavik)

What do ACE inhibitors do? (3)

1. Lower BP/decrease after load

2. Lower blood volume/decrease preload

3. Less work on heart, so the heart tends to maintain its size and shape ← less remodeling

what are some adverse reactions to ACE inhibitors?

• dry cough

• Hyperkalemia- excreted in kidney so any kidney probs can lead to this as well

What is the action of angiotensin II receptor blockers (ARBs)?

blocks angiotensin II receptor sites on vascular smooth muscle and the adrenal gland (release of aldosterone)

what are ARBs indicated for? (2)

1. HTN

2. HF

how do ARBs differ from ACE inhibitors? Why are they sometimes preferred?

ARBs don’t produce a dry cough

Preferred to ACE inhibitors bc there are fewer adverse reactions, especially those that can become severe (ex. Hyperkalemia)

How are ARBs identified?

“-sartan”

Ex.

• Losartin (Cozaar)

• Eprosartan (Teveten)

• Valsartan (Diovan)

• Irbesartan (Avapro)

• Candesartan (Atacand)

• Olmesartan (Benicar)

• Telmisartan (Micardis)

• Azilsartan (Edarbi)

what is the method of action for vasodilators?

act directly on the arterials and/or venous smooth muscle

What are some examples of vasodilators?

• minoxidil

• Hydralazine

• Diazoxide

• Nitroprusside

what is preload? When is it increased?

volume of blood coming INTO the ventricles AKA end diastolic pressure

Increased in: hypervolemia and regurgitation of cardiac values

what is afterload? When is it increased?

resistance that the left ventricle must overcome to circulate blood

Increased in: HTN and vasoconstriction

Increased afterload = increased cardiac workload

What is the goal of treatment with antihypertensives?

1. Reduce blood volume- diuretics, low sodium diet

2. Reduce cardiac output- reduce HR and/or Contractility- beta blockers

3. Lower peripheral vascular resistance- vasodilators

what are the goals of treating pre-hypertension?

1. Exercise- 5000 steps or more

2. Lower cholesterol (LDL and triglycerides)- with statins and diet

3. Moderate sodium diet

4. Prevention of diabetes

what is the drug of choice for treating HTN in pregnant women?

methyldopa

What are the stages of blood clotting?

1. Platelet aggregation

2. Thromboplastin generated

3. Prothrombin is converted to thrombin

4. Fibrinogen is converted to fibrin

what is the coagulation cascade?

production of fibrin to reinforce platelet patch ← a clot is formed!

• extrinsic pathway- stimulated by external injury (ex. Stab wound)

• Intrinsic factor- started from injury inside the blood vessel

What is the role of vitamin K in blood clotting?

It is used by the liver to form prothrombin and various factors crucial in the clotting cascade

What is the goal of anticoagulant therapy? what is the therapy indicated for?

prevent clots in VEINS

• inhibit the action or formation of one or more clotting factors and prevent clots from forming

• Used to treat thromboembolic disorders

what are the types of anticoagulant drugs? (4)

1. Heparins

2. Warfarin (Coumadin)

3. Factor Xa inhibitors

4. Thrombin inhibitors

how does heparin work?

inactivates several clotting factors to prevent clots from growing which allows the body proper time to break down the clot before it grows out of control

How does warfarin work?

inhibits vitamin K dependent clotting factors which also inhibits prothrombin synthesis

How are factor Xa inhibitors indicated for?

Prevents DVTs and pulmonary embolism

BUT DOES NOT REMOVE IT!!

how do thrombin inhibitors work?

inhibit thrombin activity which prevents fibrin clots

What lab test is important to monitor while someone is on UNFRACTIONED heparin?

aPTT levels

what are the differences between unfractionated heparin and low molecular weight heparins?

unfractionated-

• administered IV and subQ

• aPTT should be monitored frequently

Low molecular weight-

• administered ONLY subQ

• No frequent aPTT monitoring needed

What are some indications from unfractionated heparin? (4). Can it be used during pregnancy?

1. Pulmonary embolism

2. Stroke

3. DVT

4. Atrial fibrillation

Note: can be used during pregnancy