What each drug given for an acute coronary syndrome does, when it is used, whether it is for ST-elevation myocardial infarction or non-ST-elevation disease, and its key cautions.
| Drug or class | What it does | Benefit and when it is used | ST-elevation myocardial infarction versus non-ST-elevation acute coronary syndrome | Key cautions and contraindications | Source |
|---|---|---|---|---|---|
| Aspirin antiplatelet | Antiplatelet; chew and swallow at the first signs of chest pain. | Reduces mortality and reinfarction; decreases recurrent ischemia, stroke and cardiac death. | Both: common therapy for ST-elevation myocardial infarction and non-ST-elevation acute coronary syndrome. | Contraindications: allergy, recent gastrointestinal bleed, recent intracranial hemorrhage. | L8 slide 52 slide 53 slide 37 |
| Nitrates nitroglycerin | Vasodilator; sublingual until the patient is in hospital, then an intravenous infusion. | Relief of chest pain only; no mortality benefit. | Both. | Adverse reactions: hypotension, headache, reflex tachycardia. Contraindicated: hypotension and phosphodiesterase inhibitors. | L8 slide 54 slide 52 |
| Beta blockers | Lower heart rate and demand; started early: intravenous first, then oral (the course sequence; current guidelines favor oral therapy in the first day). | Taught to reduce early and late mortality, infarct size, heart failure and sudden cardiac death (the course answer; current evidence supports mainly the long-term benefit after infarction, most clearly with reduced ventricular function). | Both: common therapy for both groups. | Caution: bradycardia or hypotension, heart block, severe reactive airway disease. Avoid the intravenous route with heart failure, low cardiac output or risk of shock. | L8 slide 55 slide 52 |
| Morphine opioid analgesic | Opioid analgesic for pain. | Management of chest pain unresponsive to nitrates. | Used in ST-elevation myocardial infarction; may increase mortality in unstable angina and non-ST-elevation myocardial infarction. | Controversial. Adverse reactions: hypotension, allergy. | L8 slide 56 |
| Streptokinase fibrinolytic | Forms a stable 1:1 complex with plasminogen, exposing its catalytic site so the complex converts plasminogen to plasmin, which dissolves the clot. | Reopens the occluded coronary artery (reestablishes blood flow). | ST-elevation myocardial infarction (fibrinolytics are not recommended in non-ST-elevation disease). | Allergic reactions with fever, chills and rash; anaphylaxis; bleeding. Prior streptokinase exposure or allergic reaction is a contraindication. | L8 slide 59 slide 62 slide 63 slide 68 |
| Alteplase Activase; tissue plasminogen activator | Recombinant tissue plasminogen activator: directly activates fibrin-bound plasminogen, so plasmin forms at the clot. | Reopens the artery; very expensive. | ST-elevation myocardial infarction, best early after symptom onset; not recommended in non-ST-elevation acute coronary syndrome (bleeding risk exceeds benefit). | Bleeding, including intracranial hemorrhage; the fibrinolytic contraindications apply. | L8 slide 64 slide 65 slide 63 |
| Reteplase Retavase | Recombinant, made in Escherichia coli cells; longer half-life than alteplase. | Reopens the artery; very similar responses to the other tissue plasminogen activators. | ST-elevation myocardial infarction only. | Same bleeding risk and contraindications as the class. | L8 slide 64 slide 61 |
| Tenecteplase TNKase | Recombinant (Chinese hamster ovary cells) with substituted amino acids; longer half-life than alteplase, relatively resistant to plasminogen activator inhibitor-1 and increased affinity for fibrin. | Reopens the artery; very similar responses to the other tissue plasminogen activators. | ST-elevation myocardial infarction only. | Same bleeding risk and contraindications as the class. | L8 slide 64 slide 61 |
| Glycoprotein IIb/IIIa inhibitors | Antiplatelet agents used around percutaneous coronary intervention. | Not routinely recommended before percutaneous coronary intervention. | Used more commonly in non-ST-elevation acute coronary syndrome. | No specific caution is listed; antithrombotic drugs raise bleeding risk (general background). | L8 slide 66 slide 68 |
| P2Y12 receptor antagonists | Block the platelet P2Y12 receptor (antiplatelet). | Used before percutaneous coronary intervention and as clot prophylaxis when a stent is placed. | Used before percutaneous coronary intervention and when a stent is placed. | No specific caution is listed; antithrombotic drugs raise bleeding risk (general background). | L8 slide 66 slide 37 |
| Heparins unfractionated heparin, enoxaparin (low-molecular-weight heparin) | Anticoagulants, given with fibrinolysis or antiplatelet agents. | Used in conjunction with fibrinolysis or antiplatelet agents. | Non-ST-elevation acute coronary syndrome: enoxaparin is preferred over unfractionated heparin (older studies; current guidelines accept either). | No specific caution is listed; antithrombotic drugs raise bleeding risk (general background). | L8 slide 66 slide 68 |
| Non-ST-elevation acute coronary syndrome unstable angina and non-ST-elevation myocardial infarction | What changes compared with ST-elevation myocardial infarction. | Early treatment is similar to ST-elevation myocardial infarction. | No fibrinolytics (bleeding risk is greater than benefit); enoxaparin over heparin; glycoprotein IIb/IIIa inhibitors more often; morphine may increase mortality. | Fibrinolytics are not recommended. | L8 slide 68 slide 56 |