Unit I, Q1: Routes of Drug Administration

What does "route of administration" mean? Simply put - it means how you give a drug to a patient. The route chosen depends on the drug's properties (e.g., does it dissolve in water? Is it broken down by stomach acid?) and how fast you need it to work.

1. ENTERAL ROUTE (Through the GI Tract / Gut)

a) Oral (By Mouth) - Most Common

• The patient swallows the tablet, capsule, or liquid.
• Advantages: Easy, cheap, safe, self-administered, no needles.
• Disadvantages: Some drugs are destroyed by stomach acid. Absorption is slow. Cannot be used if patient is unconscious or vomiting.
• Special oral forms:
  • Enteric-coated tablets - have a protective coating so the drug skips the stomach and dissolves only in the intestine. Used for acid-sensitive drugs like omeprazole or stomach-irritating drugs like aspirin.
  • Extended-release (ER/SR/XL) tablets - release the drug slowly over many hours, so you need fewer doses per day. Example: Extended-release morphine (2 doses/day instead of 6).

b) Sublingual (Under the Tongue)

• The tablet is placed under the tongue and dissolves there.
• The drug is absorbed directly into blood vessels under the tongue.
• Advantages: Very fast action, bypasses liver (no first-pass metabolism), bypasses stomach acid.
• Example: Nitroglycerin for chest pain (angina) - works within minutes.

c) Buccal (Between Cheek and Gum)

• Drug is placed between the cheek and gum.
• Works similarly to sublingual - fast absorption directly into bloodstream.
• Example: Buprenorphine buccal film.

2. PARENTERAL ROUTE (Injection / Bypasses the Gut)

• A drug cannot be absorbed from the gut (e.g., heparin, insulin)
• The patient is unconscious
• A very fast effect is needed

a) Intravenous (IV) - Into a Vein

• Injected directly into a vein - fastest possible route.
• 100% of the drug reaches the bloodstream immediately.
• Can be given as a bolus (all at once) or infusion (slowly over time).
• Used in emergencies, ICU, for drugs not absorbed by mouth.
• Example: IV antibiotics, IV fluids, chemotherapy.

b) Intramuscular (IM) - Into a Muscle

• Injected into a large muscle (e.g., deltoid, gluteus).
• Absorbed more slowly than IV but faster than oral.
• Depot injections - slow-release preparations in oil/non-water vehicle that slowly dissolve in muscle, giving weeks of effect.
• Example: Vaccines (IM), Depo-Provera contraceptive injection.

c) Subcutaneous (SC) - Under the Skin

• Injected just beneath the skin into the fat layer.
• Slow, steady, sustained absorption.
• Not suitable for irritating drugs (can cause tissue damage/pain).
• Example: Insulin injections, heparin.

d) Intradermal (ID) - Into the Skin Layers

• Injected into the dermis (the layer just below the outer skin surface).
• Used for skin testing and allergy desensitization rather than systemic treatment.
• Example: Tuberculin (Mantoux) skin test for TB diagnosis.

3. OTHER ROUTES

a) Inhalation (Breathing In)

• Drug is inhaled as a gas or aerosol directly into the lungs.
• Very fast absorption (almost as fast as IV) because lungs have a huge surface area and rich blood supply.
• Advantage: Targets the lung directly, minimizing side effects on rest of the body.
• Example: Inhalers for asthma (salbutamol), anesthetic gases in surgery.

b) Nasal Route

• Drug applied directly into the nose (spray or drops).
• Absorbed through nasal mucosa.
• Example: Nasal corticosteroids for allergic rhinitis (e.g., fluticasone nasal spray).

c) Intrathecal / Intraventricular (Into the Spine/Brain)

• Drug injected directly into the spinal fluid (CSF) or brain ventricles.
• Used when the drug cannot cross the blood-brain barrier but CNS effect is needed quickly.
• Example: Spinal anesthesia (lidocaine), intrathecal antibiotics for meningitis.

d) Topical (Applied to Skin or Mucous Membranes)

• Drug applied directly to skin, eye, ear, or vagina for a local effect.
• Minimal absorption into general circulation = fewer systemic side effects.
• Example: Skin creams (hydrocortisone), eye drops (timolol for glaucoma).

e) Transdermal (Skin Patch)

• Drug absorbed through the skin into the bloodstream - a systemic effect via skin.
• Provides slow, controlled, continuous drug release.
• Example: Nicotine patch, fentanyl patch, contraceptive patch.

f) Rectal (Suppository)

• Drug inserted into the rectum as a suppository.
• Useful when patient cannot swallow (vomiting, unconscious, children).
• About 50% of the drug bypasses the liver.
• Example: Diclofenac suppository (for fever/pain), anti-emetic suppositories.

Quick Summary Table

📋 All Questions from Your PDF - B.Sc. Nursing Pharmacology I (3rd Semester)

Unit I, Q1: Routes of Drug Administration 💊

🔵 1. ENTERAL ROUTE (Through the Mouth/Gut)

a) Oral (Swallowing)

• Medicine is swallowed as tablet, capsule, or syrup
• ✅ Easy, cheap, safe, no needle
• ❌ Slow, destroyed by stomach acid, can't use if unconscious
• Example: Paracetamol tablet

b) Sublingual (Under the Tongue)

• Tablet placed under the tongue, dissolves fast
• Goes directly into blood - very fast action
• Example: Nitroglycerin for chest pain

c) Buccal (Between Cheek & Gum)

• Medicine placed between cheek and gum
• Also fast absorption like sublingual
• Example: Buprenorphine

🔴 2. PARENTERAL ROUTE (By Injection)

a) Intravenous (IV) - Into a Vein

• Fastest route - drug goes directly into blood
• Used in emergencies
• Example: IV saline, IV antibiotics

b) Intramuscular (IM) - Into Muscle

• Injected into a large muscle (arm, buttock)
• Medium speed
• Example: Vaccines, Vitamin B12 injection

c) Subcutaneous (SC) - Under Skin

• Injected just beneath the skin into fat layer
• Slow and steady absorption
• Example: Insulin injection

d) Intradermal (ID) - Into Skin

• Injected into the skin layers (not under)
• Used for testing only, not treatment
• Example: TB skin test (Mantoux)

🟢 3. OTHER ROUTES

⭐ Quick Memory Trick

"Every Patient Should Receive Treatment Immediately" Enteral → Parenteral → Sublingual → Rectal → Topical → Inhalation

Unit III, Q1: Antacids and Anti-peptic Ulcer Drugs 💊

First - What is Peptic Ulcer?

Drugs Used to Treat It

🔵 1. ANTACIDS - "Neutralize the Acid"

• These neutralize (cancel out) the acid already present in the stomach
• They give quick relief from pain and burning
• They do NOT heal the ulcer - just reduce symptoms

⚠️ Use with caution in kidney patients - can cause toxicity

🔴 2. H2 BLOCKERS (H2 Receptor Antagonists) - "Block Acid Production"

• These block the signal (histamine) that tells the stomach to make acid
• Reduce both day and night acid production
• Good for healing ulcers

• Ranitidine (most common)
• Cimetidine
• Famotidine
• Nizatidine

⚠️ Cimetidine - can cause gynecomastia (breast enlargement in men)

🟠 3. PROTON PUMP INHIBITORS (PPIs) - "Strongest Acid Stopper"

• These directly block the acid pump (H+/K+ ATPase) inside the stomach cells
• Most powerful acid-reducing drugs
• Best taken before breakfast (before meals)

• Omeprazole (most common)
• Pantoprazole
• Lansoprazole
• Rabeprazole

⚠️ Long-term use may cause bone weakness, low magnesium, kidney problems

🟢 4. CYTOPROTECTIVE DRUGS - "Protect the Stomach Lining"

🟣 5. ANTIBIOTICS (for H. pylori infection)

• Omeprazole + Amoxicillin + Clarithromycin for 7-14 days

⭐ Quick Summary Table

Unit III, Q2: Emetics & Anti-emetics 🤢

PART A - EMETICS (Drugs that CAUSE Vomiting)

What is an Emetic?

When is it used?

• When a person accidentally swallows poison or a toxic substance
• To empty the stomach quickly before it absorbs into blood
• ⚠️ NOT used if the person swallowed acid, alkali, or kerosene (vomiting those causes more damage)

Types of Emetics

⚠️ Emetics are rarely used today - doctors prefer gastric lavage (stomach wash) instead.

PART B - ANTI-EMETICS (Drugs that STOP Vomiting)

What is an Anti-emetic?

When is it used?

• Motion sickness 🚗
• Post-surgery vomiting
• Chemotherapy (cancer treatment) causes severe vomiting
• Pregnancy (morning sickness)
• Gastroenteritis (stomach infection)

Groups of Anti-emetics

🔵 1. Antihistamines (H1 Blockers)

• Block histamine signals that trigger vomiting
• Best for motion sickness and vertigo
• Side effect: Drowsiness/sedation

• Promethazine (Phenergan) - most common
• Diphenhydramine
• Cyclizine
• Meclizine

🔴 2. Dopamine Antagonists

• Block dopamine in the brain's vomiting centre (CTZ - Chemoreceptor Trigger Zone)
• Used for gastroenteritis, post-op vomiting, chemotherapy

• Metoclopramide (Perinorm) - also speeds up stomach emptying
• Prochlorperazine
• Domperidone

⚠️ Side effect: Can cause involuntary muscle movements (extrapyramidal effects)

🟠 3. Serotonin (5-HT3) Antagonists - Strongest Anti-emetics

• Block serotonin which is released during chemotherapy and triggers vomiting
• Best for chemotherapy-induced vomiting

• Ondansetron (Emeset) - most widely used
• Granisetron
• Dolasetron

✅ Very safe, minimal side effects

🟢 4. Anticholinergics

• Block nerve signals that trigger vomiting during motion
• Best for motion sickness

• Scopolamine patch - worn behind ear, lasts 72 hours

🟣 5. Corticosteroids

• Used along with other anti-emetics during chemotherapy
• Drug: Dexamethasone

🔶 6. Vitamin B6 (Pyridoxine)

• Natural, safe option
• Used for morning sickness in pregnancy
• Often combined with Doxylamine

⭐ Quick Summary

Unit III, Q3: Antidiarrheal Drugs 💊

First - What is Diarrhea?

✅ First treatment is always ORS (Oral Rehydration Solution) - replace lost water and salts!

Groups of Antidiarrheal Drugs

🔵 1. OPIOID AGONISTS - "Slow Down the Gut"

✅ Loperamide is the go-to drug for simple, non-infectious diarrhea ⚠️ Do NOT use if diarrhea has blood, high fever, or signs of serious infection - can make it worse!

🔴 2. ADSORBENTS - "Absorb the Bad Stuff"

🟠 3. BILE SALT BINDERS - "For Special Cases"

• Cholestyramine
• Colesevelam

🟢 4. ORS - Oral Rehydration Solution (Most Important!)

🏥 WHO ORS formula is life-saving especially for children with diarrhea

🟣 5. ANTIBIOTICS - "For Infective Diarrhea"

⚠️ Do NOT take antibiotics for every diarrhea - most are viral and antibiotics won't help!

🟡 6. PROBIOTICS - "Good Bacteria"

⭐ Quick Summary Table

⚠️ When NOT to Use Antidiarrheals

• Bloody diarrhea
• High fever
• Diarrhea with severe infection signs
• In these cases, see a doctor immediately!

Unit IV, Q1: Anti-asthmatic Drugs - Bronchodilators 🫁

First - What is Asthma?

The airway in asthma has 3 problems:

1. Muscles around airways tighten/squeeze (bronchoconstriction)
2. Lining becomes swollen/inflamed
3. Too much mucus produced

Two Types of Asthma Drugs

🔵 GROUP 1: β2 AGONISTS (Most Important Bronchodilators)

a) Short-Acting β2 Agonists (SABA) - "Rescue Inhalers"

• Work in 5-15 minutes, last 3-6 hours
• Used during an acute asthma attack for quick relief
• ⚠️ Overuse = heart palpitations, tremors

b) Long-Acting β2 Agonists (LABA) - "Controller"

• Last 12+ hours, taken twice daily
• NOT for acute attacks - used to prevent symptoms
• Always combined with inhaled steroids

🔴 GROUP 2: METHYLXANTHINES - "Old but Useful"

⚠️ Narrow therapeutic window - too little = no effect, too much = toxic (seizures, heart problems) ✅ Still used where inhalers are not available or affordable

🟠 GROUP 3: ANTICHOLINERGICS (Muscarinic Antagonists)

Short-Acting (SAMA):

• Ipratropium bromide (Atrovent) - inhaler, works in 15-30 min, lasts 4-6 hrs
• Used for COPD and asthma, especially combined with salbutamol

Long-Acting (LAMA):

• Tiotropium (Spiriva) - once daily, mainly for COPD

🟢 GROUP 4: INHALED CORTICOSTEROIDS (ICS) - "Best Controller"

• Must be taken daily even when feeling fine
• Do NOT give quick relief - work over days/weeks
• After use, rinse mouth to prevent fungal infection (thrush)

🟣 GROUP 5: LEUKOTRIENE ANTAGONISTS

• Taken as oral tablets daily
• Good for allergy-triggered asthma and exercise-induced asthma

🟡 GROUP 6: MAST CELL STABILISERS

⭐ Quick Summary Table

🚨 Remember - Step-wise Treatment

• Mild/occasional → Salbutamol inhaler (as needed)
• Moderate → Add daily ICS (Budesonide)
• Severe → ICS + LABA combination (e.g., Symbicort)
• Acute attack in hospital → IV Aminophylline + IV Steroids + Oxygen

Unit IV, Q2: Expectorants & Antitussives 🫁

PART A - EXPECTORANTS 💧

What is an Expectorant?

Think of it like this: thick sticky mucus is stuck in your airways like glue. Expectorants add water to it and make it loose and runny so you can cough it out easily.

When is it used?

• Chest congestion (blocked airways with thick mucus)
• Bronchitis, pneumonia, COPD
• Any condition with productive cough (cough with phlegm)

Types of Expectorants

🔵 1. Guaifenesin (Most Common)

• Thins the mucus and helps it move out
• Available in many cough syrups OTC (e.g., Mucinex, Benadryl expectorant)
• Side effects: Very few - mild nausea, headache
• ✅ Safe, widely used, well tolerated

🔵 2. Potassium Iodide

• Stimulates mucus glands to produce more watery mucus
• ⚠️ Causes more side effects - thyroid problems, skin rash, not safe in pregnancy
• Less commonly used now

🔵 3. Mucolytics (Drugs that BREAK DOWN mucus)

🔵 4. Hypertonic Saline (Nebulised Salt Water)

• Inhaled through a nebuliser
• Draws water into airways, loosening thick mucus
• Used especially in cystic fibrosis patients

⭐ Summary of Expectorants

💡 Drink plenty of water when taking expectorants - it helps them work better!

PART B - ANTITUSSIVES (Cough Suppressants) 🤫

What is an Antitussive?

Cough is controlled by a cough centre in the brain (medulla). Antitussives either act on the brain to suppress it, or act on the airways to reduce the trigger.

When is it used?

• Dry, irritating cough that serves no purpose (no phlegm)
• Night cough keeping the patient awake
• Cough after respiratory infections

⚠️ Do NOT use antitussives for productive cough (cough with phlegm) - you NEED to cough out the mucus!

Types of Antitussives

🔴 1. Opioid Antitussives - "Act on Brain" (Centrally Acting)

🔴 2. Non-Opioid Antitussives - "Brain Acting but No Addiction"

🟠 3. Peripherally Acting Antitussives - "Act on Airway"

⭐ Summary of Antitussives

🔑 KEY DIFFERENCE TO REMEMBER

Unit V, Q1: Haematinics 💊🩸

What are Haematinics?

Anaemia = low haemoglobin (Hb) in blood → less oxygen carried → tiredness, pale skin, weakness, breathlessness

There are 3 Main Haematinics:

🔴 1. IRON - For Iron Deficiency Anaemia

Why do we need Iron?

Causes of Iron Deficiency:

• Poor diet (not eating enough iron-rich foods)
• Blood loss (heavy periods, bleeding)
• Pregnancy (baby uses mother's iron)
• Rapid growth in children

Signs of Iron Deficiency Anaemia:

• Fatigue, weakness, pale skin
• Pica - craving to eat ice, dirt, clay 🧊
• Koilonychia - spoon-shaped nails
• Cracks at corners of mouth

Treatment - Iron Supplements:

✅ Take with Vitamin C (orange juice) - helps iron absorb better ⚠️ Side effects: Constipation, nausea, dark/black stools, stomach cramps ✅ Takes 2-4 weeks to see improvement

• Iron sucrose (IV) - most commonly used
• Iron dextran, Ferric carboxymaltose
• Used when: patient can't tolerate oral iron, has malabsorption, kidney disease

🟡 2. FOLIC ACID (Vitamin B9) - For Megaloblastic Anaemia

Why do we need Folic Acid?

Without folic acid:

• RBCs become very large but few in number = Megaloblastic anaemia
• High MCV (large cell size) on blood test

Causes of Folic Acid Deficiency:

• Poor diet (no green vegetables)
• Alcoholism 🍺
• Pregnancy (high demand)
• Drugs: Methotrexate, Phenytoin, Trimethoprim

Treatment:

• Folic acid tablet 5 mg daily orally
• Very safe, excess is excreted in urine
• All pregnant women must take folic acid to prevent baby's neural tube defects (spina bifida)

🔵 3. VITAMIN B12 (Cyanocobalamin) - For Pernicious Anaemia

Why do we need Vitamin B12?

Pernicious Anaemia:

Signs of B12 Deficiency:

• Megaloblastic anaemia (large RBCs)
• Tingling/pins and needles in hands and feet
• Difficulty walking, memory problems
• In severe cases: dementia, hallucinations

Treatment:

⚠️ IMPORTANT: In megaloblastic anaemia, NEVER give only folic acid - always give BOTH folic acid + B12, because giving folic acid alone can hide B12 deficiency while nerve damage continues silently!

🟢 4. ERYTHROPOIETIN (EPO) - Special Haematinic

• A hormone made by the kidneys that tells bone marrow to make RBCs
• Used in anaemia of chronic kidney disease or chemotherapy patients
• Given as SC injection: Epoetin alfa, Darbepoetin

⭐ Quick Summary Table

🥦 Food Sources to Remember

• Iron: Red meat, spinach, dates, jaggery
• Folic acid: Green leafy vegetables, lentils, beans
• Vitamin B12: Meat, fish, eggs, dairy (vegans are at risk!)

Unit V, Q2: Anti-Hypertensive Drugs 💊❤️

First - What is Hypertension?

• Normal BP: 120/80 mmHg
• High BP: ≥140/90 mmHg

Non-Drug Treatment First:

• Reduce salt in diet 🧂
• Lose weight
• Exercise regularly
• Stop smoking, reduce alcohol
• Eat fruits and vegetables (DASH diet)

Drug Groups for Hypertension

🔵 1. DIURETICS - "Water Pills"

Thiazide Diuretics (First-line for most patients):

✅ First choice in most hypertension cases ⚠️ Side effects: Low potassium, raised blood sugar, raised uric acid (gout)

Loop Diuretics (for severe cases / kidney disease):

• Furosemide (Lasix) - stronger, used in heart failure + hypertension

Potassium-Sparing Diuretics:

• Spironolactone - saves potassium, used in resistant hypertension

🔴 2. ACE INHIBITORS - "Block the Pressure Hormone"

✅ Best for: Hypertension + Diabetes, hypertension + kidney disease, heart failure ⚠️ Side effect: Dry cough (very common - main reason patients stop), high potassium ❌ Avoid in pregnancy

🟠 3. ARBs - Angiotensin Receptor Blockers - "Same effect, no cough"

✅ Best for: Diabetes + hypertension, kidney protection ❌ Avoid in pregnancy

🟢 4. CALCIUM CHANNEL BLOCKERS (CCBs) - "Relax the Blood Vessels"

Dihydropyridines (mainly for BP):

Non-Dihydropyridines (BP + heart rate):

✅ Very effective, good for elderly patients and Black patients ⚠️ Side effects: Ankle swelling, flushing, headache

🟣 5. BETA BLOCKERS - "Slow the Heart Down"

✅ Best for: Hypertension + Angina, hypertension + after heart attack, heart failure ⚠️ Side effects: Fatigue, cold hands/feet, slow heart rate, impotence ❌ Avoid in asthma (causes bronchospasm) Not first-line for uncomplicated hypertension anymore

🟡 6. ALPHA BLOCKERS

⚠️ Side effect: First dose hypotension - dizziness when standing up

🔶 7. CENTRALLY ACTING DRUGS

⭐ Quick Summary Table

🔑 Remember: First-Line Drugs (A-B-C-D)

A - ACE Inhibitors / ARBs B - Beta Blockers C - Calcium Channel Blockers D - Diuretics (Thiazide)

Unit V, Q3: Anti-Anginal Drugs 💊❤️‍🔥

First - What is Angina?

Think of the heart like a car engine. If the fuel supply (blood) is blocked, the engine overheats and gives warning signs = chest pain.

Types of Angina:

The Problem in Angina:

Heart needs MORE oxygen than it is getting Solution = either reduce heart's oxygen demand OR increase blood supply to heart

Drug Groups for Angina

🔴 1. NITRATES - "First Line, Fast Relief"

How they work:

Short-Acting (for ACUTE attack):

✅ Place under tongue during chest pain - works in minutes! Keep in airtight glass bottle - loses potency if exposed to air ⚠️ Side effects: Headache, flushing, dizziness, low BP

Long-Acting (for PREVENTION):

⚠️ Tolerance develops with long-acting nitrates - give a "nitrate-free period" of 8-10 hrs daily (usually at night) to prevent tolerance

🔵 2. BETA BLOCKERS - "Reduce Heart's Workload"

✅ Best for: Stable angina, post-heart attack prevention ⚠️ Side effects: Slow heart rate, fatigue, cold hands ❌ Avoid in: Asthma, variant angina (spasm) - can worsen spasm!

🟠 3. CALCIUM CHANNEL BLOCKERS (CCBs) - "Relax Vessels + Heart"

Two types:

✅ Best for Variant (Prinzmetal) Angina - most effective for coronary spasm ✅ Safe in asthma (unlike beta blockers) ⚠️ Side effects: Ankle swelling, constipation (verapamil), flushing

🟢 4. ANTIPLATELET DRUGS - "Prevent Clots"

🟣 5. RANOLAZINE - "Newer Drug"

⭐ Quick Summary Table

🔑 Which Drug for Which Angina:

Unit V, Q4: Anticoagulants 💊🩸

First - What are Anticoagulants?

They do NOT dissolve existing clots - they just stop NEW clots from forming and stop existing ones from getting bigger.

When are They Used?

• DVT (Deep Vein Thrombosis) - clot in leg veins
• Pulmonary Embolism (PE) - clot in lung
• Atrial Fibrillation - irregular heartbeat causing clots
• After heart valve replacement surgery
• During and after heart attack
• Prevention after major surgery (hip/knee replacement)

How Does Blood Clot? (Simple Version)

Anticoagulants block these clotting factors so clots can't form.

Drug Groups

🔴 1. HEPARIN - "Fast Acting Injectable"

What it is:

• A natural substance extracted from animal tissue (pig intestine, cow lung)
• Given by injection only (IV or SC) - cannot be taken by mouth

How it works:

• Activates Antithrombin III (a natural clot stopper in the body)
• Antithrombin III then blocks Thrombin + Factor Xa → no clot formation

Types:

• Enoxaparin (Clexane) - most common
• Dalteparin
• Fondaparinux

✅ Drug of choice in PREGNANCY - safe because it cannot cross the placenta ✅ LMWH is easier to use (predictable dose, less monitoring, can use at home) ⚠️ Main side effect: Bleeding ⚠️ Rare but serious: HIT (Heparin-Induced Thrombocytopenia) - low platelets caused by heparin itself

Antidote for Heparin:

🔵 Protamine Sulfate - reverses heparin overdose immediately

🔵 2. WARFARIN - "Oral Long-Term Anticoagulant"

How it works:

• Blocks Vitamin K in the liver
• Vitamin K is needed to make clotting factors II, VII, IX, X
• Without Vitamin K → fewer clotting factors made → blood takes longer to clot

Key Facts:

• Oral tablet - taken once daily
• Slow onset - takes 3-5 days to work fully (must overlap with heparin at the start)
• Narrow therapeutic window - too little = clot, too much = bleeding
• Monitored by INR (International Normalised Ratio) blood test
  • Target INR = 2.0 to 3.0 for most conditions
  • Higher INR = more anticoagulated = more bleeding risk

Drug/Food Interactions (Important!):

• Vitamin K foods (spinach, broccoli, cabbage) REDUCE warfarin effect
• Many drugs INCREASE or DECREASE warfarin effect
• Requires regular blood test monitoring

Antidote for Warfarin:

🟢 Vitamin K (Phytomenadione) - reverses warfarin 🩸 Fresh Frozen Plasma (FFP) - for emergency reversal

🟠 3. NEWER ORAL ANTICOAGULANTS (NOACs / DOACs)

✅ Fixed dose, no routine blood test monitoring needed ✅ Fewer drug and food interactions than warfarin ⚠️ Cannot be used in severe kidney disease Antidote: Idarucizumab for dabigatran; Andexanet alfa for Xa inhibitors

⭐ Quick Summary Table

🔑 Key Points to Remember:

Unit V, Q5: Antiarrhythmics 💊❤️

First - What is Arrhythmia?

Normal heart rate = 60-100 beats/minute, regular rhythm

• Tachycardia - too fast (>100 bpm)
• Bradycardia - too slow (<60 bpm)
• Atrial Fibrillation (AF) - irregular, chaotic beats in upper chambers
• Ventricular Tachycardia (VT) - dangerous fast rhythm in lower chambers
• Ventricular Fibrillation (VF) - most dangerous - no proper heartbeat = cardiac arrest

Classification - Vaughan-Williams System

🔴 CLASS I - Sodium Channel Blockers

Idea: Block sodium channels → slow down electrical signals in heart → correct fast/abnormal rhythms

Class IA - Intermediate

⚠️ Side effects: Low BP, anticholinergic effects (dry mouth, blurred vision), can worsen arrhythmia

Class IB - Fast/Weak (mainly ventricular)

✅ Lidocaine is given IV in emergencies for life-threatening VT

Class IC - Slow/Potent

⚠️ Dangerous in patients with previous heart attack or heart failure - can cause lethal arrhythmia

🔵 CLASS II - Beta Blockers

Idea: Block adrenaline (beta receptors) → heart beats slower and more regularly

✅ Very safe, widely used ⚠️ Avoid in asthma, avoid in heart block

🟠 CLASS III - Potassium Channel Blockers

Idea: Block potassium channels → prolong the heart's "refractory period" (rest time between beats) → prevents re-entry circuits that cause arrhythmia

Amiodarone - Most Important Drug:

✅ Most powerful antiarrhythmic available ✅ Works on Class I, II, III, and IV mechanisms ⚠️ Long-term side effects: Thyroid problems (hypo/hyperthyroidism), lung toxicity (pulmonary fibrosis), liver toxicity, skin turns blue-grey in sunlight, corneal deposits in eyes Must monitor thyroid, liver, lungs regularly

🟢 CLASS IV - Calcium Channel Blockers

Idea: Block calcium channels in heart's conduction system → slow AV node → control fast heart rate

⚠️ Do NOT use in heart failure or with beta blockers (dangerous combination) ⚠️ Do NOT use in VT - can cause collapse

🟡 OTHER (Miscellaneous) Antiarrhythmics

⭐ Quick Summary Table

🔑 Emergency Drugs to Remember:

• VT/VF cardiac arrest → Amiodarone IV, Lidocaine IV
• SVT (sudden fast heart rate) → Adenosine IV (terminates it in seconds!)
• AF rate control → Digoxin, Verapamil, Beta blocker
• Bradycardia (too slow) → Atropine IV