Hello, उड़ीसा।
Namaste! 🙏
Hello! How can I help you today? Feel free to ask me anything - in Hindi, Odia, English, or any language you prefer!
आप किस विषय में सहायता चाहते हैं? 😊
Oris, take me-- Tell me the treatment of and loading dose of MI.
Reading File
Finding Sources
Finding Sources
Searching PubMed
"myocardial infarction" AND "antiplatelet" AND "loading dose"
Reading File
Reading File
Reading File
Reading File
Reading File
I now have comprehensive data. Let me compile the complete answer.
Treatment of Myocardial Infarction (MI) - Full Guide
1. Initial Management (First 10 Minutes)
- 12-lead ECG within 10 minutes of arrival
- Supplemental O2 if SpO2 < 90%
- IV access, cardiac monitoring, telemetry
- Labs: Troponin, CBC, coagulation, creatinine, electrolytes, lipid profile
2. Upstream Medical Therapy (Medications + Loading Doses)
A. Antiplatelet Agents
| Drug | Loading Dose | Maintenance | Key Notes |
|---|---|---|---|
| Aspirin (ASA) | 162-325 mg (chewed/crushed) | 75-100 mg/day | Non-enteric coated - chewed for faster absorption. First drug to give. |
| Clopidogrel | 600 mg orally | 75-150 mg/day | 600 mg LD + 150 mg/day for 7d may reduce stent thrombosis. Caution in elderly. |
| Prasugrel | 60 mg orally | 10 mg/day | More potent than clopidogrel. Contraindicated in age >75 y, weight <60 kg, history of stroke/TIA. |
| Ticagrelor | 180 mg orally | 90 mg twice daily | Mortality benefit over clopidogrel. ASA dose must NOT exceed 100 mg when used. |
| Cangrelor | 30 mcg/kg IV bolus | 4 mcg/kg/min infusion | IV agent. PCI use only. |
DAPT (Dual Antiplatelet Therapy) = Aspirin + one P2Y12 inhibitor, for 12 months post-MI.
B. Anticoagulants
| Drug | Loading Dose | Maintenance | Notes |
|---|---|---|---|
| UFH (Unfractionated Heparin) | 60 units/kg IV bolus (max 4000 units) | 12 units/kg/h | All PCI patients and thrombolytic patients (except streptokinase). |
| Enoxaparin (LMWH) | 30 mg IV bolus, then 1 mg/kg SC | 1 mg/kg SC every 12h | In elderly >75 y: NO loading dose; use 0.75 mg/kg SC. Give extra 0.3 mg/kg if last dose >8h before PCI. |
| Bivalirudin | 0.75 mg/kg IV bolus | 1.75 mg/kg/h | PCI use; not studied with thrombolytics. |
| Fondaparinux | 2.5 mg SC | 2.5 mg SC/day | NSTEMI/conservative strategy. Not for primary PCI. |
C. Anti-Ischemic Agents
| Drug | Dose | Notes |
|---|---|---|
| Nitroglycerin | 0.4 mg sublingual x3, then IV 5-10 mcg/min | Avoid if SBP <90, RV infarction, or PDE5 inhibitor use |
| Morphine | 2-4 mg IV | Pain relief; use cautiously (may delay antiplatelet absorption) |
| Beta-blocker (e.g., metoprolol) | 25-50 mg PO | Avoid if acute HF, bradycardia, heart block, or hypotension |
| Statin (e.g., atorvastatin) | 80 mg loading dose | High-intensity statin initiated immediately |
| ACE inhibitor/ARB | Start within 24h | Especially if EF reduced, anterior STEMI, or HF |
3. Reperfusion Strategy
Primary PCI (Preferred)
- Goal: Door-to-balloon time < 90 minutes
- First choice if PCI-capable center is available within 120 minutes
Fibrinolytic Therapy (if PCI not available within 120 minutes)
| Agent | Dose | Notes |
|---|---|---|
| Tenecteplase (TNK-tPA) | Weight-based single IV bolus | Drug of choice - single bolus, convenient, lower bleeding risk |
| Alteplase (rt-PA) | 15 mg IV bolus, then 0.75 mg/kg over 30 min, then 0.5 mg/kg over 60 min | Fibrin-selective |
| Reteplase (r-PA) | 10 units IV x2 (30 min apart) | Double bolus |
| Streptokinase | 1.5 million units IV over 60 min | Non-fibrin-selective; cheapest; widely used globally. Do NOT repeat if used before (antibodies). |
- Must be given within 12 hours of symptom onset (best within 3 hours)
- Give within 30 minutes of hospital arrival (Door-to-needle)
Contraindications to Thrombolytics
- Absolute: Prior intracranial hemorrhage, ischemic stroke <3 months, known AVM/aneurysm/tumor, head trauma <3 months, aortic dissection, active bleeding
- Relative: Prior stroke >3 months, recent major surgery (<3 weeks), active PUD, CPR >10 min, pregnancy
4. Post-Reperfusion / Secondary Prevention
| Drug | Duration |
|---|---|
| DAPT (Aspirin + P2Y12) | 12 months |
| ACE inhibitor/ARB | Indefinite if EF reduced or HF |
| Beta-blocker | Indefinite |
| High-intensity statin | Indefinite |
| Aldosterone antagonist | If EF <40% + HF/diabetes |
5. Mnemonic: "MONA + BASH"
- M - Morphine (pain)
- O - Oxygen (if SpO2 <90%)
- N - Nitrates
- A - Aspirin (162-325 mg, chew it!)
- B - Beta-blocker
- A - Anticoagulation
- S - Statin (high-dose)
- H - Heparin / reperfusion (PCI or fibrinolytic)
Sources: The Washington Manual of Medical Therapeutics; Harrison's Principles of Internal Medicine, 22nd Ed.; Braunwald's Heart Disease
This is a shared conversation. Sign in to Orris to start your own chat.