Anticoagulants, Antiplatelets, Thrombolytics and Haematinics for NEET PG Pharmacology: ICMR STEMI Protocol, Heparin, Warfarin, DOACs, Iron

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🎯 Exam priority: Very high. Expect: a STEMI patient far from a cath lab, a thrombolysis contraindication, heparin vs warfarin monitoring and antidotes, clopidogrel with omeprazole, and an anaemic pregnant woman's iron dose.

CBME mapping: PH 4.8–4.11. Indian doses follow the ICMR STEMI and NSTEMI workflows (January 2026) and Anemia Mukt Bharat.

Acute Coronary Syndrome: ICMR Protocol

• STEMI, first steps: aspirin 325 mg + clopidogrel 300 mg + atorvastatin 80 mg; oxygen only if saturation < 90%.

• Reperfusion: transfer for PCI if it can be done within 120 minutes; otherwise thrombolyse within 12 hours of symptom onset, preferably with a fibrin-specific agent (tenecteplase, alteplase, reteplase), streptokinase if those are unavailable. Start within 10 minutes.

• After thrombolysis: ECG at 60–90 minutes. Success = > 50% ST resolution with pain relief → PCI within 3–24 hours; failure → transfer immediately. Enoxaparin (preferred over UFH) until PCI or discharge.

• Absolute contraindications to thrombolysis include previous intracerebral haemorrhage or stroke of unknown cause, ischaemic stroke in the last 6 months, major trauma, surgery, head injury or GI bleed within 1 month, a known bleeding tendency (except menses), severe uncontrolled hypertension, CNS tumour or AV malformation, and aortic dissection.

• Dual antiplatelets: at least 1 year after STEMI; after PCI for NSTEMI, at least 12 months with a drug-eluting stent and 3 months with a bare-metal stent.

Antiplatelets and Fibrinolytics

Fibrinolytics (tenecteplase, alteplase, reteplase, streptokinase) are plasminogen activators. Streptokinase can cause allergic reactions, especially if given before. Tenecteplase is one bolus over 5 seconds.

Acute ischaemic stroke: the ICMR stroke workflow allows IV tPA within 0–4.5 hours; the US alteplase label says within 3 hours, at 0.9 mg/kg (maximum 90 mg), 10% as a 1-minute bolus. Aspirin is for secondary prevention after ischaemic stroke.

Anticoagulants

Anticoagulants: target, monitoring test and reversal agent, from the drugs' prescribing labels. Drawn by TrackNation.

• Heparin: changes antithrombin's shape so it inhibits Xa and thrombin. Watch for HIT: platelets fall 5–10 days after first exposure; stop heparin.

• Enoxaparin: boxed warning for spinal or epidural haematoma with neuraxial anaesthesia. With creatinine clearance < 30 mL/min, the dose was given once every 24 hours.

• Warfarin: dose varies with CYP2C9 and VKORC1 genes, diet and drugs; INR 2–3. Contraindicated in pregnancy (embryopathy) except with mechanical valves. Skin necrosis is linked to protein C or S deficiency.

• DOACs: dabigatran (thrombin) causes dyspepsia; apixaban and rivaroxaban (Xa); rivaroxaban is taken with food. Not for mechanical valves.

• Vitamin K injection: boxed warning for fatal hypersensitivity by IV or IM route; prefer subcutaneous.

Haematinics and Erythropoietin

Pregnancy anaemia cut-offs: mild 10–10.9, moderate 7–9.9, severe < 7 g/dL. Vitamin C helps iron absorption. Ferric carboxymaltose has a boxed warning for severe, prolonged hypophosphataemia. Pernicious anaemia may cause subacute combined degeneration of the cord; oral B12 is unreliable in it.

Traps the Examiner Sets

• PCI within 120 minutes beats thrombolysis; otherwise thrombolyse within 12 hours.

• Heparin → aPTT, protamine. Warfarin → INR, vitamin K. Dabigatran → idarucizumab.

• Clopidogrel needs CYP2C19 to work; omeprazole blunts it.

• Prasugrel is contraindicated after a stroke or TIA.

• Ticagrelor is reversible and causes breathlessness.

• Folic acid alone in B12 deficiency is wrong treatment.

Memory Hooks & Shortcuts

Shortcuts to lock in this article's numbers and lists. Each one only re-packages facts proven above.

• 🧠 120 to cut, 12 to clot-bust — PCI if within 120 minutes; otherwise thrombolysis within 12 hours

• 🧠 Heparin → aPTT → Protamine; Warfarin → INR → K — test and antidote pairs

• 🧠 Dabigatran's Dab of Idarucizumab — dabigatran is reversed by idarucizumab

• 🧠 Clopi needs a CYP key (2C19) — clopidogrel must be activated; omeprazole blocks the key

• 🧠 Prasugrel: no Past Stroke — contraindicated after TIA or stroke

• 🧠 Ticagrelor makes you Tired of breathing — dyspnoea

• 🧠 60–500 for mums: iron 60, folate 500 — Anemia Mukt Bharat IFA tablet

Rapid-Revision Cards

• STEMI loading (ICMR)

  Aspirin 325 + clopidogrel 300 + atorvastatin 80.

• PCI or lyse?

  PCI if within 120 min; else thrombolyse within 12 h.

• Thrombolysis start

  Within 10 min; fibrin-specific preferred.

• Tenecteplase dose

  35/40/45 mg bolus by weight.

• Streptokinase dose

  1.5 million U over 60 min; allergy on reuse.

• Successful lysis

  >50% ST resolution + pain relief → PCI in 3–24 h.

• Absolute contraindications

  Past ICH, ischaemic stroke < 6 months, trauma/surgery/GI bleed < 1 month, aortic dissection.

• Ticagrelor (ICMR)

  180 mg, then 90 mg BD; reversible; dyspnoea.

• Prasugrel

  60 mg then 10 mg; not after TIA/stroke.

• Clopidogrel

  Prodrug via CYP2C19; irreversible; avoid omeprazole.

• Aspirin

  Irreversible COX-1 and COX-2 inhibitor.

• DAPT duration

  ≥ 12 months with DES; 3 months with BMS.

• UFH (ICMR)

  60 U/kg (max 5000), 12 U/kg/h, aPTT 50–70 s.

• Protamine

  1 mg ≈ 100 U heparin; 1 mg per 1 mg enoxaparin.

• HIT

  Platelets fall day 5–10; stop heparin.

• Enoxaparin

  1 mg/kg SC 12-hourly; daily if CrCl < 30; spinal haematoma.

• Warfarin

  VKORC1; INR 2–3; vitamin K, PCC/FFP.

• Warfarin in pregnancy

  Contraindicated (embryopathy) except mechanical valves.

• Dabigatran

  Thrombin inhibitor; idarucizumab; dyspepsia.

• Apixaban, rivaroxaban

  Xa inhibitors; rivaroxaban with food.

• Mechanical valve

  Warfarin, not DOACs.

• Alteplase (stroke)

  0.9 mg/kg, max 90, 10% bolus; ICMR ≤ 4.5 h.

• IFA tablet (AMB)

  60 mg iron + 500 mcg folic acid.

• Pregnancy IFA

  1 daily from 4th month, 180 days; 2 daily if Hb 7–10.9.

• Severe anaemia in pregnancy

  Hb < 7: refer urgently to DH/FRU.

• B12 vs folate

  Folic acid alone wrong in B12 deficiency.

• EPO warning

  Hb target > 11 raises death, MI, stroke.

Sources

Facts in this article were checked against these documents.

• Standard Treatment Workflows: STEMI; Unstable Angina/NSTEMI; Atrial Fibrillation — Indian Council of Medical Research / Department of Health Research, MoHFW, January 2026

• Standard Treatment Workflow for the Management of Stroke — Indian Council of Medical Research, MoHFW, October 2019

• Anemia Mukt Bharat: Intensified National Iron Plus Initiative, Operational Guidelines — Ministry of Health and Family Welfare, 2018

• Medications for Acute Coronary Syndromes; Treatment of Pain — MSD Manual Professional Version, accessed November 2026 (link)

• Prescribing labels: warfarin (Jantoven), heparin sodium, Lovenox, Eliquis, Xarelto, dabigatran, Praxbind, Plavix, Brilinta, Effient, Activase, TNKase, phytonadione injection, Injectafer, Venofer, cyanocobalamin, folic acid, Epogen — DailyMed, US National Library of Medicine, current labels, accessed November 2026 (link)

• Competency Based Undergraduate Curriculum, Pharmacology (PH 4.8–4.11) — National Medical Commission, 2024

Test Yourself: Practice Questions

Twenty-eight questions in NEET PG style, most of them clinical vignettes.

Practice Questions (NEET PG pattern)

Original questions written in the style of the exam: +4 for a correct answer, −1 for a wrong one. Every answer was checked against the sources listed above. NEET PG papers are not published by NBEMS, so these are not past-paper questions.

Q1. A 55-year-old with a 3-hour anterior STEMI is at a hospital without a cath lab; the nearest PCI centre cannot do PCI within 120 minutes. Per ICMR, the next step is

• (a) observe and repeat ECG in 24 hours

• (b) heparin alone

• (c) thrombolysis, preferably with a fibrin-specific agent

• (d) transfer anyway and wait for PCI

Q2. A 75-kg man with STEMI is to receive tenecteplase. The ICMR dose is

• (a) 50 mg infusion over 1 hour

• (b) 35 mg single IV bolus

• (c) 40 mg single IV bolus

• (d) 1.5 million units over 60 minutes

Q3. A woman with STEMI had an ischaemic stroke 2 months ago. Thrombolysis is

• (a) allowed with half dose

• (b) allowed if BP is normal

• (c) absolutely contraindicated

• (d) preferred over PCI

Q4. Ninety minutes after tenecteplase for STEMI, chest pain is gone and ST elevation has fallen by 70%. ICMR advises

• (a) repeat thrombolysis

• (b) no further intervention ever

• (c) transfer for PCI within 3–24 hours

• (d) immediate rescue PCI

Q5. A man received streptokinase for an MI years ago and now has another STEMI. A concern with repeating streptokinase is

• (a) QT prolongation

• (b) allergic reactions, especially after previous use

• (c) hypokalaemia

• (d) hypoglycaemia

Q6. The ICMR loading doses on diagnosing STEMI are

• (a) aspirin 150 mg + heparin 1000 U

• (b) aspirin 325 mg + clopidogrel 300 mg + atorvastatin 80 mg

• (c) aspirin 75 mg alone

• (d) clopidogrel 75 mg + warfarin

Q7. In NSTEMI, ticagrelor is given as

• (a) 300 mg loading, then 75 mg daily

• (b) 60 mg loading, then 10 mg daily

• (c) 325 mg loading, then 75 mg daily

• (d) 180 mg loading, then 90 mg twice daily

Q8. A 68-year-old with NSTEMI had a TIA last year. Which P2Y12 inhibitor is contraindicated?

• (a) Prasugrel

• (b) None of them

• (c) Clopidogrel

• (d) Ticagrelor

Q9. A patient on clopidogrel after a stent is prescribed omeprazole for dyspepsia. The label advises

• (a) doubling clopidogrel

• (b) avoiding omeprazole because it reduces clopidogrel's effect

• (c) no concern

• (d) stopping clopidogrel

Q10. Genetic testing shows a patient is a CYP2C19 poor metaboliser. For ACS antiplatelet therapy, consider

• (a) a higher clopidogrel dose only

• (b) another P2Y12 inhibitor instead of clopidogrel

• (c) aspirin alone

• (d) warfarin

Q11. A man started on ticagrelor after MI complains of breathlessness; exam and ECG are unchanged. The likely cause is

• (a) pulmonary embolism from ticagrelor

• (b) reinfarction

• (c) aspirin asthma

• (d) ticagrelor-induced dyspnoea, usually self-limiting

Q12. Aspirin differs from other NSAIDs because it

• (a) selectively inhibits COX-2

• (b) blocks P2Y12

• (c) inhibits COX-1 and COX-2 irreversibly

• (d) activates plasminogen

Q13. After NSTEMI, a patient gets a drug-eluting stent. ICMR advises dual antiplatelet therapy for

• (a) 2 weeks

• (b) at least 12 months

• (c) 3 months only

• (d) lifelong double therapy

Q14. The ICMR unfractionated heparin regimen in ACS is

• (a) 1 mg/kg SC once daily

• (b) 5000 U SC twice daily without monitoring

• (c) titrate to INR 2–3

• (d) 60 U/kg bolus (max 5000 U), then 12 U/kg/hour, aPTT 50–70 s

Q15. A patient on IV heparin bleeds heavily. Heparin is reversed with protamine, and

• (a) vitamin K is equally effective

• (b) each mg of protamine neutralises about 100 units of heparin

• (c) the dose is 1 mg per kg

• (d) idarucizumab is the antidote

Q16. On day 7 of heparin for DVT, a woman's platelet count halves and she develops a new clot. The step is

• (a) stop heparin (suspected HIT)

• (b) increase heparin

• (c) give platelets and continue heparin

• (d) add protamine

Q17. A patient with creatinine clearance 20 mL/min needs enoxaparin for ACS. In the label's trials, the dose was

• (a) 1 mg/kg every 12 hours

• (b) 1 mg/kg every 24 hours

• (c) 1.5 mg/kg every 6 hours

• (d) not adjusted

Q18. A patient on enoxaparin is scheduled for spinal anaesthesia. The boxed warning is

• (a) epidural or spinal haematoma

• (b) hypokalaemia

• (c) hepatotoxicity

• (d) QT prolongation

Q19. Warfarin acts by

• (a) directly inhibiting thrombin

• (b) activating antithrombin

• (c) inhibiting VKORC1, reducing regeneration of vitamin K

• (d) blocking factor Xa directly

Q20. After starting warfarin, a woman with hereditary protein C deficiency develops skin necrosis. The label links this to

• (a) an infection only

• (b) heparin allergy

• (c) vitamin K overdose

• (d) warfarin lowering protein C and S

Q21. A woman on warfarin for a past DVT (no heart valve) finds she is 6 weeks pregnant. Warfarin is

• (a) only a concern after 36 weeks

• (b) safe throughout pregnancy

• (c) preferred over heparin in pregnancy

• (d) contraindicated: it causes warfarin embryopathy

Q22. A man on dabigatran for AF needs emergency surgery. The specific reversal agent is

• (a) vitamin K

• (b) fresh frozen plasma only

• (c) protamine

• (d) idarucizumab

Q23. A patient with a mechanical mitral valve and AF needs anticoagulation. The drug is

• (a) warfarin

• (b) apixaban

• (c) dabigatran

• (d) aspirin alone

Q24. A 60-year-old with acute ischaemic stroke arrives 2 hours after onset; CT shows no bleed. Alteplase is dosed at

• (a) 0.9 mg/kg (max 90 mg), 10% as a bolus

• (b) 0.1 mg/kg infusion over 24 hours

• (c) a fixed 10 mg

• (d) 1.5 mg/kg as a single bolus

Q25. At 22 weeks, a pregnant woman has Hb 8.5 g/dL. Under Anemia Mukt Bharat she gets

• (a) immediate blood transfusion

• (b) 1 IFA tablet weekly

• (c) folic acid alone

• (d) 2 IFA tablets daily

Q26. Each Anemia Mukt Bharat IFA tablet for pregnant women contains

• (a) 100 mg elemental iron + 5 mg folic acid

• (b) 60 mg elemental iron + 500 mcg folic acid

• (c) 200 mg ferrous sulphate only

• (d) 30 mg iron + 400 mcg folic acid

Q27. A 65-year-old with macrocytic anaemia and a low serum B12 level is started on folic acid alone. This is

• (a) safe if given IV

• (b) improper: folic acid alone does not treat B12-deficient megaloblastic anaemia

• (c) correct first-line therapy

• (d) preferred over B12

Q28. A dialysis patient's erythropoietin dose is raised to reach Hb 13 g/dL. The boxed warning is that targeting Hb above 11 g/dL

• (a) increases the risk of death, MI and stroke

• (b) causes iron overload only

• (c) has no added risk

• (d) causes hypoglycaemia

Active Recall

From memory: give the ICMR STEMI reperfusion rules and loading doses, the absolute contraindications to thrombolysis, how heparin, enoxaparin, warfarin and DOACs are monitored and reversed, the differences between aspirin, clopidogrel, prasugrel and ticagrelor, and the Anemia Mukt Bharat iron-folic acid regimen in pregnancy.