INICET Hematology Pharmacology Glossary 2026: Anticoagulants, Antiplatelets, Thrombolytics and Iron Therapy — High-Yield Drug Classes and MCQ Mnemonics

You are probably staring at your pharmacology notes thinking: "How am I supposed to remember 30+ hematology drugs, their mechanisms, reversals, and side effects for INICET?" Here's the reality — INICET hematology pharmacology questions test just 4 major drug classes, but they test them ruthlessly. One question asks about heparin reversal, the next about warfarin interactions, then aspirin resistance, then streptokinase contraindications.

INICET loves testing drug comparisons. UFH vs LMWH. Warfarin vs DOACs. Aspirin vs clopidogrel. Streptokinase vs alteplase. The examiners want to see if you can pick the right drug for the right patient in the right clinical scenario. This glossary covers exactly that — the 4 highest-yield drug classes with INICET-specific MCQ mnemonics and clinical pearls that actually show up in the exam.

Why These 4 Drug Classes Matter for INICET

INICET hematology pharmacology follows a predictable pattern. About 60% of questions come from anticoagulants and antiplatelets combined. Another 25% from thrombolytics. The remaining 15% from iron therapy and miscellaneous blood-related drugs. When you master these 4 classes, you have covered 85% of possible INICET hematology pharmacology MCQs.

The twist? INICET doesn't ask basic MOA questions. They test clinical applications, drug interactions, reversals, and side effects. A typical question: "A 65-year-old patient on warfarin presents with INR 8.5 and minor bleeding. Best immediate management?" The answer isn't warfarin MOA — it's knowing that vitamin K 2.5mg PO is preferred over FFP for minor bleeding with INR 5-10.

Anticoagulants: The High-Yield Quartet

Heparin Family: UFH vs LMWH

Unfractionated Heparin (UFH)

• Mechanism: Binds antithrombin III → inactivates factors IIa (thrombin) and Xa

• Route: IV/SC only

• Monitoring: aPTT (target 1.5-2.5x normal)

• Reversal: Protamine sulfate (1mg per 100 units of heparin)

• Half-life: 1-2 hours

Low Molecular Weight Heparin (LMWH) - Enoxaparin

• Mechanism: Primarily anti-Xa activity (less anti-IIa than UFH)

• Route: SC only

• Monitoring: Anti-Xa levels (usually not needed)

• Reversal: Protamine partially effective (60-80%)

• Half-life: 4-6 hours

INICET Mnemonic - "HEPARIN Monitoring":

• Half-life: UFH short, LMWH long

• Elimination: UFH renal+hepatic, LMWH renal

• Partial reversal: LMWH with protamine

• APTT monitoring: UFH yes, LMWH no

• Renal adjustment: LMWH needs, UFH doesn't

• IV possible: UFH yes, LMWH no

• Neutralizable: UFH completely, LMWH partially

For students working through hematology MCQs, every question about heparin reversal gets an AI explanation covering why protamine works for UFH but only partially for LMWH — turning each attempt into active pharmacology learning.

Warfarin: The Vitamin K Antagonist

Mechanism: Inhibits vitamin K epoxide reductase → blocks synthesis of factors II, VII, IX, X + proteins C & S Key Clinical Points:

• Monitoring: INR (target varies by indication)

• Onset: 48-72 hours (factor VII depleted first)

• Peak effect: 5-7 days

• Reversal: Vitamin K (PO/IV), FFP, PCC (Prothrombin Complex Concentrate)

Major Drug Interactions (INICET Favorites):

• Potentiate warfarin (↑INR): Metronidazole, sulfamethoxazole, amiodarone, cimetidine, erythromycin

• Antagonize warfarin (↓INR): Phenytoin, carbamazepine, rifampin, barbiturates

INICET Mnemonic - "WARFARIN Interactions":

• Weakens with phenytoin/rifampin

• Augmented by metronidazole/amiodarone

• Rifampin reduces effect

• Factors II, VII, IX, X blocked

• Anticoagulation reversed by vitamin K

• Requires 3-5 days to reach steady state

• INR monitoring essential

• Needs CYP2C9 metabolism

Direct Oral Anticoagulants (DOACs)

Rivaroxaban & Apixaban (Factor Xa Inhibitors)

• Mechanism: Direct factor Xa inhibition

• Monitoring: Not routinely needed

• Reversal: Andexanet alfa (expensive), PCC as alternative

• Advantages: Fixed dosing, fewer interactions

Dabigatran (Direct Thrombin Inhibitor)

• Mechanism: Direct thrombin (factor IIa) inhibition

• Monitoring: Not routinely needed

• Reversal: Idarucizumab (specific antidote)

• Renal elimination: 80% (requires dose adjustment in CKD)

Students using Synapses flashcards can save DOAC comparison tables for spaced repetition — essential for retaining the differences between rivaroxaban's once-daily dosing vs apixaban's twice-daily regimen before INICET.

Antiplatelet Agents: Targeting Different Pathways

Aspirin: The COX-1 Inhibitor

Low-dose Aspirin (75-100mg)

• Mechanism: Irreversibly inhibits COX-1 → blocks TXA2 synthesis → reduces platelet aggregation

• Duration: Permanent (platelet lifespan 7-10 days)

• Side effects: GI bleeding, tinnitus, Reye syndrome (children)

INICET Pearl: Aspirin resistance occurs in 10-15% patients. Alternative: clopidogrel, not higher aspirin dose.

P2Y12 Inhibitors: ADP Pathway Blockers

Clopidogrel

• Mechanism: Irreversibly blocks P2Y12 ADP receptors

• Onset: 4-6 hours (requires hepatic conversion to active metabolite)

• Duration: 5-7 days

• Key interaction: PPI (especially omeprazole) reduces efficacy

Ticagrelor

• Mechanism: Reversibly blocks P2Y12 receptors

• Onset: 30 minutes (no hepatic conversion needed)

• Duration: 3-4 days

• Side effect: Dyspnea (10-15% patients)

Prasugrel

• Mechanism: Irreversibly blocks P2Y12 receptors

• Onset: 15-30 minutes

• Contraindication: History of stroke/TIA

• Advantage: No CYP2C19 interaction (unlike clopidogrel)

INICET Mnemonic - "CLOPI-TICAGREL-PRASUGREL":

• Clopidogrel: CYP2C19 dependent, PPI interaction

• Lasting 5-7 days (irreversible)

• Onset slow (4-6 hours)

• Platelet function affected

• Irreversible binding

• Ticagrelor: Takes 30 minutes onset

• Independent of CYP metabolism

• Causes dyspnea

• Active without conversion

• Good in ACS

• Reversible binding

• Expires in 3-4 days

• Less stroke risk than prasugrel

GP IIb/IIIa Inhibitors

Abciximab, Eptifibatide, Tirofiban

• Mechanism: Block final common pathway of platelet aggregation

• Use: IV only, acute settings (PCI, ACS)

• Monitoring: Bleeding time, platelet count

• Reversal: Platelet transfusion

Thrombolytic Agents: Clot Busters

Streptokinase

Mechanism: Activates plasminogen → plasmin → fibrin degradation INICET High-Yield Facts:

• Antigenic: Can cause allergic reactions, antibody formation

• Hypotension: Most common side effect (30-40% patients)

• Contraindication: Previous streptokinase use (within 1 year), recent surgery

• Cost: Cheapest thrombolytic

Alteplase (tPA)

Mechanism: Tissue plasminogen activator — fibrin-specific thrombolysis Advantages over streptokinase:

• Non-antigenic: No allergic reactions

• Fibrin-specific: Less systemic plasminogen activation

• Faster: 90-minute vs 3-hour infusion

• Efficacy: Better mortality reduction in STEMI

Tenecteplase: Single bolus version of alteplase, weight-based dosing INICET Mnemonic - "STREP vs tPA":

• Strep causes allergies, tPA safe

• Time: Strep 3 hours, tPA 90 minutes

• Reactions: Strep antigenic, tPA not

• Effectiveness: tPA superior

• Price: Strep cheaper, tPA expensive

When working through anticoagulant pharmacology lessons, students often miss the streptokinase antigenicity concept. Oncourse's adaptive system automatically increases thrombolytic questions if you consistently miss this high-yield INICET pattern.

Common Thrombolytic Contraindications (INICET Traps)

Absolute Contraindications:

• Active bleeding

• Intracranial hemorrhage (any time)

• Recent head trauma (<3 months)

• Known intracranial neoplasm

Relative Contraindications:

• Recent surgery (<14 days)

• Uncontrolled hypertension (>180/110)

• Active peptic ulcer disease

• Pregnancy

Iron Therapy: Deficiency to Overload

Oral Iron Preparations

Ferrous Sulfate (Most Common)

• Elemental iron: 20% (65mg elemental iron per 325mg tablet)

• Absorption: Best on empty stomach, with vitamin C

• Side effects: GI upset, constipation, dark stools

• Interactions: Reduced by antacids, tea, calcium

Ferrous Fumarate: 33% elemental iron (highest concentration) Ferrous Gluconate: 12% elemental iron (best tolerated) INICET Pearl: Iron absorption increases 3-4 fold in iron deficiency. Normal absorption is only 5-10%.

Intravenous Iron

Iron Sucrose

• Dose: 100-200mg per infusion

• Frequency: 2-3 times per week

• Side effects: Hypotension, anaphylaxis (rare)

Ferric Carboxymaltose

• Advantage: Single large dose (up to 1000mg)

• Onset: Faster than iron sucrose

• Cost: More expensive

INICET Indications for IV Iron:

• Severe iron deficiency (Hb <7 g/dL)

• Oral iron intolerance

• Malabsorption syndromes

• Chronic kidney disease

• Heart failure patients

Iron Chelation Therapy

Deferoxamine

• Route: IV/SC infusion

• Mechanism: Binds free iron → forms ferrioxamine → renal excretion

• Side effects: Ototoxicity, retinal toxicity, growth retardation

• Monitoring: Audiometry, ophthalmology exams

Deferasirox (Oral Chelator)

• Advantage: Once daily oral dosing

• Side effects: Nephrotoxicity, hepatotoxicity, GI upset

• Monitoring: Creatinine, liver function tests

INICET Mnemonic - "IRON Chelation":

• IV deferoxamine for acute poisoning

• Renal toxicity with deferasirox

• Oral deferasirox for chronic use

• Needs monitoring (kidney, liver, eyes, ears)

Students can create iron therapy flashcards comparing oral vs IV preparations — crucial for remembering that ferrous fumarate has the highest elemental iron content but ferrous sulfate remains most commonly used.

INICET MCQ Traps and Clinical Pearls

Heparin-Induced Thrombocytopenia (HIT)

Type 1 HIT: Mild, transient thrombocytopenia within 2 days Type 2 HIT: Severe, paradoxical thrombosis + thrombocytopenia after 5-10 days Management: Stop heparin immediately, start argatroban or bivalirudin INICET Trap: Never use LMWH in HIT — cross-reactivity occurs in 80% cases

Warfarin Reversal Guidelines

Aspirin vs Clopidogrel Selection

Use Aspirin when:

• Primary prevention (low bleeding risk)

• Cost is a factor

• No GI contraindications

Use Clopidogrel when:

• Aspirin allergy/intolerance

• High GI bleeding risk

• Recent GI bleeding on aspirin

Streptokinase vs Alteplase in STEMI

Choose Streptokinase if:

• Cost limitation

• No previous streptokinase use

• Patient hemodynamically stable

Choose Alteplase if:

• Previous streptokinase use

• Time-critical situation

• High bleeding risk (fibrin-specific)

Advanced INICET Concepts

Dual Antiplatelet Therapy (DAPT) Duration

Post-PCI with stents:

• Bare metal stents: 4 weeks minimum

• Drug-eluting stents: 6-12 months standard

• High bleeding risk: Shorter duration acceptable

INICET Question Pattern: They ask about optimal DAPT duration after presenting a patient with specific bleeding risk factors.

Anticoagulation in Special Populations

Pregnancy:

• Safe: UFH, LMWH

• Contraindicated: Warfarin (teratogenic), DOACs (unknown safety)

Renal Impairment:

• Dose reduction needed: Dabigatran (80% renal excretion)

• Minimal adjustment: Rivaroxaban, apixaban (25-35% renal excretion)

Liver Disease:

• Avoid warfarin in severe hepatic impairment

• DOACs relatively safer but use with caution

Frequently Asked Questions

What is the most common side effect of streptokinase?

Hypotension occurs in 30-40% of patients receiving streptokinase. This is why IV fluids are often co-administered during infusion. The mechanism involves kinins and complement activation leading to vasodilation.

When should you suspect heparin-induced thrombocytopenia?

Suspect HIT when platelet count drops >50% from baseline after 5-10 days of heparin therapy, especially if paradoxical thrombosis occurs. The 4T score helps assess probability: Thrombocytopenia severity, Timing, Thrombosis, and other causes.

Which oral iron preparation has the highest elemental iron content?

Ferrous fumarate contains 33% elemental iron, making it the highest among oral preparations. However, ferrous sulfate remains most commonly prescribed due to cost and availability, containing 20% elemental iron.

What is the reversal agent for dabigatran?

Idarucizumab is the specific reversal agent for dabigatran, neutralizing its anticoagulant effect within minutes. For other DOACs (rivaroxaban, apixaban), andexanet alfa is used, though prothrombin complex concentrate (PCC) serves as an alternative.

Can LMWH be used in patients with heparin-induced thrombocytopenia?

No, LMWH should never be used in HIT due to 80% cross-reactivity with UFH antibodies. Alternative anticoagulants include argatroban, bivalirudin, or fondaparinux.

Why is vitamin C given with iron supplements?

Vitamin C (ascorbic acid) reduces ferric iron (Fe3+) to ferrous iron (Fe2+), which is the absorbable form. This can increase iron absorption by 3-4 fold, especially important in iron deficiency anemia treatment.

Prepare smarter with Oncourse AI — adaptive MCQs, spaced repetition, and AI explanations built for INICET. Download free on Android and iOS.