Cardiac and ANS Medications Overview

Cardiac Medications

• These medications affect the cardiovascular system and often have more than one pharmacological/therapeutic class, used for various purposes.

Drugs Affecting the Autonomic Nervous System (ANS)

• Part 1: Drugs affecting the ANS include cholinergic agonists/antagonists and adrenergic blocking agents.
• Types: Anticholinergic agents affect cholinergic pathways, while adrenergic agents affect adrenergic pathways. Adrenergic blocking agents are also included.

Important Cardiac Pharmacology Terms

• Inotrope: Strength of contraction
• Chronotropic: Heart rate
• Dromotropic: Conduction through the AV node

Cholinergic Agonists (Parasympathomimetic)

• Effects: Acetylcholine and Pilocarpine affect the parasympathetic nervous system with various routes of administration.
• Uses: Atonic bladder conditions, GI disorders, glaucoma, and salivary gland hypofunction.
• Interactions: Any other drugs affecting the parasympathetic nervous system.
• Adverse Effects: GI issues, blurred vision, bradycardia, hypotension, shortness of breath (SOB).

Cholinergic Anticholinesterase Drugs

• Action: Reversible or irreversible drugs that stop the breakdown of acetylcholine. Examples include donepezil and neostigmine
• Uses: Glaucoma, GI disorders, bladder disorders, antidote for cholinergic blocking agents, dementia, Myasthenia gravis.
• Adverse Effects: Cardiac arrhythmias, preterm labor, GI issues, and breathing problems.

Anticholinergic Drugs

• Source: Belladonna alkaloids (i.e., atropine, scopolamine) and synthetic substances, (i.e., Glycopyrrolate).
• Action: These drugs block the stimulation of cholinergic receptors.
• Uses: Dry up respiratory secretions, treat sympathetic bradycardia, relax GI muscle, treat bladder issues, dilate pupils for exams/surgery, antidote for cholinergic/anticholinesterase drugs.
• Interactions: Cardiac drugs, antiemetics, tricyclic antidepressants.
• Adverse Effects: Dry mouth, blurred vision, tachycardia, and others depending on the dose.

Adrenergic Drugs (Catecholamines)

• Type: Sympathomimetic effect; examples: Dopamine, Epinephrine, and Norepinephrine.
• Note: Usually administered intravenously.
• Pharmacodynamics: Excitatory responses except with intestinal relaxation; impact depends on dosage and administration route.
• Effects: Increase heart rate and strength (positive inotrope and chronotrope), depending on the specific receptor activated (e.g., Alpha, Beta 1, Beta 2).

Adrenergic Blocking Drugs

• Action: Disrupt the sympathetic nervous system (sympatholytic).
• Naming: Named by the site of action (Alpha/Beta/Central).
• Beta Blockers: Most commonly used; prevent the stimulation of the nervous system; important to ensure the patient's heart rate is above 60 bpm before administration.
  • Types: Non-selective (Carvedilol, labetalol, sotalol, timolol) and selective (Atenolol, esmolol, metoprolol) block different receptors.
• Pharmacodynamics: Interfere/block norepinephrine synthesis, release, and reuptake.
• Uses: Hypertension, peripheral vascular disorders, migraine headaches, opioid withdrawal, and mild sedation.
• Interactions: Caffeine, antibiotics, cardiac medications, and CNS depressants.
• Adverse Effects: Edema, angina, orthostatic hypotension, and arrhythmias.

Part 2: Control of HR, Rhythm, BP, Chest Pain, and Cholesterol

• Inotropic Drugs: Affect the force of heart contractions.
• Antiarrhythmic Drugs: Treat abnormal heart rhythms.
• Antianginal Drugs: Treat chest pain (angina).
• Antihypertensive Drugs: Treat high blood pressure.
• Diuretics: Increase urine output.
• Antilipemic Drugs: Lower cholesterol and triglycerides.

Inotropic (Increasing the Force of Heart Contractions)

• Example: Digoxin is an important inotropic agent used in heart failure.
• Note: Monitor for adverse effects, serum potassium and digoxin levels, and kidney function. Hold if apical pulse is less than 60 bpm.

Antiarrhythmics (For Abnormal Heart Rhythms)

• Classes I through IV: These classes affect different aspects of sodium, potassium, calcium or other important mechanisms in the cardiac and smooth muscle activity.
• Note: Ensure baseline pulse is above 60 bpm before administration.
• Examples: Class I - Sodium channel blockers; Class III - Drugs that prolong the refractory period; Class IV - Calcium channel blockers

Antianginal Drugs (For Chest Pain)

• Example: The nitrates class like nitroglycerin, and Beta blockers, calcium channel blockers already covered are some therapeutic options.
• Notes: Administered through various routes (oral, sublingual, transdermal, intravenous), with specific considerations depending on the route. For instance, transdermal patches need site rotation to avoid tolerance to and sensitivity to the medication.

Antihypertensives (For High Blood Pressure)

• Thiazide Diuretics: Often the first choice; regulate fluid balance, affecting multiple parts of the circulatory and excretory systems.
• ACE Inhibitors (Prils): Block the conversion of angiotensin I to angiotensin II to decrease blood pressure. Examples: Ramipril, Enalapril
• ARB's (Sartans): Block angiotensin II from binding to its receptors to decrease blood pressure. Examples: Losartan, Valsartan, Irbesartan
• Direct Vasodilators: Relax smooth muscles in blood vessels. Examples: Hydralazine, Nitroprusside

Antilipemic Drugs (To Lower High Cholesterol/Triglycerides)

• Fibric Acid Derivatives: Reduce triglycerides. Example: Fenofibrate
• HMG-CoA Reductase Inhibitors ("Statins"): Reduce LDL cholesterol. Example: Atorvastatin
• Nicotinic Acid: Reduce triglycerides and raise HDL cholesterol. Example: Niacin
• Cholesterol Absorption Inhibitors: Reduce cholesterol absorption. Example: Ezetimibe
• Notes: Nursing considerations on potential kidney and liver function tests are important.

Explore the vital aspects of cardiac medications and drugs influencing the autonomic nervous system. This quiz covers essential pharmacological terms, adrenergic and cholinergic agents, and their therapeutic applications. Test your knowledge on how these drugs interact and their uses in various medical conditions.