Clinical Pharmacology of Acute coronary syndrome Flashcards
How does thrombolytic therapy work?
Thrombolytics (e.g., streptokinase, tissue plasminogen activator (tPA)) convert plasminogen to plasmin, breaking down fibrin in clots and restoring coronary blood flow.
When is thrombolytic therapy used?
STEMI if PCI is unavailable within 2 hours.
Massive pulmonary embolism with haemodynamic instability.
Ischaemic stroke (tPA, within 4.5 hours of onset).
What are the benefits of thrombolysis in STEMI?
Rapid reperfusion of coronary arteries.
Reduces infarct size, preserving heart function.
Improves survival if given early (<12 hours of symptom onset).
What are the risks of thrombolytic therapy?
Major bleeding, especially intracranial haemorrhage.
Reperfusion arrhythmias.
Allergic reactions (streptokinase).
What are the landmark trials proving thrombolysis benefits?
GISSI-1 (1986) → Showed streptokinase improved survival in MI.
ISIS-2 (1988) → Confirmed streptokinase + aspirin significantly reduced mortality.
How does aspirin help in MI and ischaemic heart disease?
Irreversibly inhibits COX-1 enzyme, preventing platelet aggregation.
Reduces risk of recurrent MI and stroke.
Lowers cardiovascular mortality.
What are the weaknesses of aspirin?
Gastrointestinal bleeding risk.
Aspirin resistance in some patients.
What are the key medications for MI treatment?
Aspirin + P2Y12 inhibitor (e.g., clopidogrel, ticagrelor) → Prevents further clot formation.
Thrombolysis (if PCI unavailable within 2 hours).
Beta-blockers (e.g., bisoprolol, metoprolol) → Reduce heart rate and oxygen demand.
ACE inhibitors (e.g., ramipril) → Reduce heart failure risk.
Statins (e.g., simvastatin, atorvastatin) → Lower LDL cholesterol and stabilize plaques.
What are the major complications post-MI?
Arrhythmias → Ventricular fibrillation, atrial fibrillation.
Heart failure → Due to left ventricular dysfunction.
Cardiogenic shock → Severe pump failure.
Pericarditis (Dressler’s syndrome) → Autoimmune response post-MI.
Left ventricular aneurysm → Can lead to embolism or rupture.
What are key components of cardiac rehabilitation?
Lifestyle modifications → Diet, exercise, smoking cessation.
Medication adherence.
Psychological support → Reducing anxiety and depression.
Gradual return to activity under supervision.
Who are high-risk MI patients?
Diabetics, hypertensive, chronic kidney disease patients.
Patients with previous MI or heart failure.
Persistent angina or significant ECG abnormalities.
What follow-up investigations are done post-MI?
ECG + Echocardiography → Assess function.
Lipid profile, HbA1c, blood pressure monitoring.
Exercise stress testing for residual ischaemia.
Strengths and Weaknesses of Drug Therapies (beta-blockers, calcium channel blockers and low dose aspirin)
Beta-Blockers
✅ Reduce mortality, arrhythmias, and reinfarction risk.
❌ Bradycardia, fatigue, bronchospasm (contraindicated in asthma).
Calcium Channel Blockers
✅ Good for hypertension and angina in those intolerant to beta-blockers.
❌ Can cause ankle swelling, dizziness, reflex tachycardia (dihydropyridines like amlodipine).
Low-Dose Aspirin
✅ Reduces platelet aggregation, MI, and stroke risk.
❌ GI bleeding, aspirin resistance.
What roles do these drugs play in long-term prevention?
Beta-blockers → Reduce recurrence and improve survival.
Simvastatin (statins) → Lower LDL, stabilize plaques.
ACE inhibitors → Prevent heart failure and hypertension.
Aspirin → Prevent clot formation.
What are common adverse reactions?
Aspirin → GI bleeding, ulcers.
Beta-blockers → Bradycardia, hypotension, fatigue.
ACE inhibitors → Cough, hyperkalaemia, angioedema.
Statins → Muscle pain, liver dysfunction.
What are benefits, ADRs and any extra info on Asprin?
(Antiplatelet)
✅ Benefits: Reduces clot formation, prevents MI & stroke.
❌ ADRs:
GI bleeding (irritates stomach lining).
Peptic ulcers.
Aspirin-induced asthma (in sensitive patients).
💡 Tip: Use proton pump inhibitors (PPIs) (e.g., omeprazole) if high bleeding risk.
What are benefits, ADRs and any extra info on Beta-blockers?
(e.g., Bisoprolol, Metoprolol)
✅ Benefits: Reduces heart rate, BP, and cardiac workload.
❌ ADRs:
Bradycardia (low heart rate).
Hypotension (dizziness, fainting).
Fatigue, cold extremities (reduced circulation).
Bronchospasm (contraindicated in asthma!).
💡 Tip: Avoid abrupt withdrawal → Can cause rebound tachycardia & hypertension.
What are benefits, ADRs and any extra info on ACE inhibitors?
(e.g., Ramipril, Lisinopril)
✅ Benefits: Lowers BP, prevents heart failure.
❌ ADRs:
Dry cough (due to bradykinin buildup).
Hyperkalaemia (high potassium, arrhythmias).
Angioedema (swelling of lips, face – rare but serious!).
💡 Tip: Switch to ARBs (e.g., Losartan) if cough is problematic.
What are benefits, ADRs and any extra info on Statins?
(e.g., Simvastatin, Atorvastatin)
✅ Benefits: Lowers LDL cholesterol, stabilizes plaques.
❌ ADRs:
Muscle pain & weakness (myopathy, rhabdomyolysis in severe cases!).
Liver dysfunction (↑ liver enzymes).
💡 Tip: Monitor creatine kinase (CK) levels for muscle damage & LFTs for liver function.
