Pharmacotherapy of myocardial infarction from shanbag or kd triphati for 6 marks in point or flow chart

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I now have enough information to give a comprehensive, exam-ready answer. The library doesn't have KD Tripathi or Shanbhag directly, but these Indian textbooks follow the same standard pharmacotherapy framework as Katzung, Goodman & Gilman, and Washington Manual - all of which are in the library. The pharmacotherapy of MI is a well-established topic.

Pharmacotherapy of Myocardial Infarction

(As per KD Tripathi / Shanbhag - 6 Marks)

OVERVIEW FLOWCHART

ACUTE MI (STEMI / NSTEMI)
         │
         ▼
┌─────────────────────────────────────────────────────┐
│           IMMEDIATE / INITIAL MANAGEMENT            │
│  O - Oxygen (if SpO₂ < 90%)                        │
│  N - Nitrates (sublingual/IV) → ↓ preload, pain    │
│  A - Aspirin 325 mg (chewed) → antiplatelet        │
│  M - Morphine IV → pain, anxiety, vasodilation     │
└─────────────────────────────────────────────────────┘
         │
         ▼
┌──────────────────────────────────────────────────────┐
│            REPERFUSION THERAPY (STEMI)               │
│  PCI (preferred) within 90 min                      │
│  OR                                                 │
│  Thrombolytics (if PCI unavailable/delay > 120 min) │
└──────────────────────────────────────────────────────┘
         │
         ▼
┌──────────────────────────────────────────────────────┐
│          ADJUNCT / CONSOLIDATION THERAPY            │
│  - Dual Antiplatelet (DAPT)                         │
│  - Anticoagulants                                   │
│  - Beta-blockers                                    │
│  - ACE inhibitors / ARBs                            │
│  - Statins                                          │
└──────────────────────────────────────────────────────┘

DETAILED POINT-WISE PHARMACOTHERAPY

1. ANALGESICS / SYMPTOMATIC RELIEF

Drug	Dose	Action
Morphine	2-4 mg IV (repeat q5-10 min)	Relieves pain, reduces anxiety, venodilatation → ↓ preload
Nitrates (GTN)	0.4 mg SL or IV infusion	↓ preload, ↓ cardiac work, dilates coronary vessels
Oxygen	2-4 L/min (only if SpO₂ < 90%)	Prevents hypoxia-induced extension of infarct

2. ANTIPLATELET DRUGS (DAPT - Dual Antiplatelet Therapy)

a) Aspirin (COX inhibitor)

Dose: 150-325 mg loading, then 75-100 mg/day
Inhibits TXA₂ → prevents platelet aggregation
Given immediately, continued indefinitely

b) P2Y₁₂ ADP receptor blockers (second antiplatelet)

Drug	Loading Dose	Mechanism
Clopidogrel	300-600 mg then 75 mg/day	Irreversible P2Y₁₂ block; prodrug
Ticagrelor	180 mg then 90 mg BD	Reversible P2Y₁₂ block; faster onset; preferred
Prasugrel	60 mg then 10 mg/day	Irreversible; most potent; used with PCI

DAPT = Aspirin + one P2Y₁₂ blocker → continued for 12 months post-MI

3. ANTICOAGULANTS

Used to prevent thrombus propagation:

Drug	Notes
Unfractionated Heparin (UFH)	IV bolus + infusion; aPTT monitored
Low Molecular Weight Heparin (LMWH) - Enoxaparin	SC; predictable dosing; no monitoring needed
Fondaparinux	Factor Xa inhibitor; preferred in NSTEMI (lower bleeding risk)
Bivalirudin	Direct thrombin inhibitor; used during PCI

4. THROMBOLYTICS (Fibrinolytics) - for STEMI only

Indication: STEMI when PCI not available within 120 min of first medical contact

Drug	Mechanism	Notes
Streptokinase	Activates plasminogen (indirect, non-fibrin-specific)	Cheapest; antigenic; avoid repeat use
Alteplase (t-PA)	Fibrin-specific plasminogen activator	Preferred; given with heparin
Tenecteplase (TNK-tPA)	Single IV bolus; fibrin-specific	Most convenient; weight-based dosing
Reteplase	Double bolus IV	Intermediate choice

Contraindications: Recent surgery/trauma, hemorrhagic stroke, severe uncontrolled HTN, active bleeding

"Time is muscle" - Thrombolysis within 6 hrs (up to 12 hrs) of onset

5. BETA-BLOCKERS

Drugs: Metoprolol, Atenolol, Carvedilol
Start: Oral within 24 hrs (IV only if tachycardia/hypertension without HF)
Mechanism: ↓ HR, ↓ BP, ↓ O₂ demand → ↓ infarct size, prevent arrhythmias
Benefit: Reduce mortality, prevent sudden cardiac death
Continue: Indefinitely post-MI
Contraindications: Acute HF, bradycardia, heart block, severe bronchospasm

6. ACE INHIBITORS / ARBs

Drugs: Ramipril, Captopril, Enalapril (ACEIs); Valsartan (ARB if ACEI intolerant)
Start: Within 24 hrs, especially if EF < 40%, anterior MI, or HF
Mechanism: Block RAAS → ↓ afterload, prevent cardiac remodeling, reduce mortality
Continue: Indefinitely in patients with reduced EF

7. STATINS (HMG-CoA Reductase Inhibitors)

Drugs: Atorvastatin 40-80 mg/day, Rosuvastatin 20-40 mg/day
Start: Immediately (within 24 hrs) regardless of baseline LDL
Mechanism: ↓ LDL, plaque stabilization, anti-inflammatory effects
Continue: Indefinitely; reduce reinfarction and mortality

8. ALDOSTERONE ANTAGONISTS

Drug: Eplerenone / Spironolactone
Indication: Post-MI with EF ≤ 40% + HF symptoms or diabetes
Benefit: Further reduces mortality (EPHESUS trial)

SUMMARY TABLE - "DRUG MNEMONIC: MONABASH"

Letter	Drug Class
M	Morphine
O	Oxygen
N	Nitrates
A	Aspirin (+ P2Y₁₂)
B	Beta-blocker
A	Anticoagulant
S	Statin
H	Heparin / ACE inhibitor

LONG-TERM / SECONDARY PREVENTION (Post-MI)

Aspirin (indefinitely) + P2Y₁₂ for 12 months
Beta-blocker (indefinitely if EF reduced)
ACE inhibitor/ARB (indefinitely if EF ≤ 40%)
Statin (indefinitely, high-intensity)
Eplerenone (if EF ≤ 40% with HF/DM)
Nitrates (PRN for angina)
Lifestyle modification + Cardiac rehab

Sources: Katzung Basic & Clinical Pharmacology 16e (Ch. 12 - Drugs used in angina/ACS); Washington Manual of Medical Therapeutics; Goodman & Gilman's Pharmacological Basis of Therapeutics - content consistent with KD Tripathi Essentials of Medical Pharmacology and Shanbhag's Review of Pharmacology frameworks for this topic.

Exam tip for 6 marks: Focus on: (1) MONA in acute phase, (2) Thrombolytics with drugs + mechanism, (3) Antiplatelet DAPT, (4) Beta-blocker + ACEI + Statin rationale, and (5) Long-term secondary prevention. Use the table/flowchart format above to score full marks.

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