Antiemetics & Coagulation Pharmacology Vocabulary

Comprehensive vocabulary flashcards covering antiemetic drugs, coagulation modifiers, anemia treatments, key receptors, adverse effects, antidotes, and hemostasis concepts from the lecture notes.

Serotonin Receptor Antagonists

Drug class that blocks 5-HT3 receptors in the CTZ and GI tract to prevent nausea and vomiting.

Ondansetron (Zofran)

Prototype 5-HT3 blocker used for chemotherapy- and post-operative-induced nausea; risk of QT prolongation.

Dopamine Antagonists

Broad class that blocks D2 receptors (phenothiazines, prokinetics) to control emesis.

Phenothiazines

Dopamine-blocking antiemetics such as promethazine and prochlorperazine; cause EPS, sedation.

Promethazine

Phenothiazine antiemetic with boxed warnings for severe tissue injury and respiratory depression <2 yrs.

Prochlorperazine

Phenothiazine dopamine antagonist used for CINV and PONV; monitor for EPS and sedation.

Prokinetics

Agents that enhance GI acetylcholine activity and block D2 receptors; example: metoclopramide.

Metoclopramide (Reglan)

Prokinetic/antiemetic for gastroparesis, GERD, CINV; boxed warning for tardive dyskinesia.

Cannabinoids

Antiemetic class that stimulates CB1/CB2 receptors in the brain to reduce CINV.

Dronabinol (Marinol)

Oral cannabinoid (Schedule III) for CINV and appetite stimulation; may cause euphoria, tachycardia.

Anticholinergic Drugs

Block muscarinic receptors in vestibular nuclei; used mainly for motion sickness (e.g., scopolamine).

Scopolamine

Transdermal anticholinergic applied behind ear 4 h before travel; lasts 72 h; avoid in glaucoma/BPH.

Antihistamines (antiemetic)

H1 antagonists that dampen vestibular signals to vomiting center; cause sedation and dry mouth.

Meclizine (Antivert)

Long-acting H1 blocker for motion sickness and vertigo; less sedating than diphenhydramine.

Dimenhydrinate

OTC antihistamine (Dramamine) taken 30–60 min before travel to prevent motion sickness.

Hydroxyzine

Prescription antihistamine with antiemetic, antipruritic, and anxiolytic properties; causes sedation.

Ginger

Herbal product used orally for motion or morning sickness; may increase bleeding with anticoagulants.

Doxylamine + Vitamin B6

First-line combination for pregnancy-related nausea; taken on a schedule, not PRN.

Chemotherapy-Induced N/V (CINV)

Severe emesis triggered by chemotherapeutics; ondansetron is first-line prophylaxis.

Post-Operative N/V (PONV)

Emesis following anesthesia; treated with ondansetron or promethazine.

Motion Sickness

Vestibular-mediated nausea; best prevented with scopolamine patch or antihistamines.

Diabetic Gastroparesis

Delayed gastric emptying in diabetics; metoclopramide is drug of choice.

Vertigo

Sense of spinning dizziness; meclizine often used for symptomatic relief.

Chemoreceptor Trigger Zone (CTZ)

Medullary area that detects emetogenic toxins; primary site for many antiemetics.

5-HT3 Receptor

Serotonin receptor subtype involved in emetic signaling; blocked by ondansetron.

D2 Receptor

Dopamine receptor subtype in CTZ; antagonism reduces nausea but may cause EPS.

CB1/CB2 Receptors

Cannabinoid receptors in CNS and periphery; agonism provides antiemetic and appetite effects.

Anticholinergic Effects

Dry mouth, blurred vision, constipation, urinary retention, confusion resulting from muscarinic blockade.

Extrapyramidal Symptoms (EPS)

Drug-induced movement disorders such as dystonia or Parkinsonism; linked to phenothiazines.

QT Prolongation

Lengthening of cardiac repolarization on ECG; risk with ondansetron and other agents.

Scopolamine Patch Application

Apply to clean, hairless skin behind ear at least 4 h pre-travel; change every 3 days.

Tardive Dyskinesia

Irreversible involuntary movements from chronic dopamine blockade; boxed warning for metoclopramide.

BOXED WARNING (Promethazine Tissue Injury)

IV promethazine can cause severe skin necrosis; always dilute and use large vein.

Heparin

IV/SC anticoagulant that enhances antithrombin III; monitored by aPTT; antidote: protamine.

Low Molecular Weight Heparin (Enoxaparin)

SC factor Xa inhibitor with predictable kinetics; minimal monitoring; partial reversal by protamine.

Heparin-Induced Thrombocytopenia (HIT)

Immune reaction causing platelet drop and thrombosis; stop heparin, switch to argatroban/fondaparinux.

Warfarin

Oral vitamin K antagonist; requires INR 2–3 monitoring; many drug-food interactions; antidote: vitamin K.

INR (International Normalized Ratio)

Standardized PT value used to dose warfarin; therapeutic range usually 2.0–3.0.

Direct Oral Anticoagulants (DOACs)

Modern oral agents (factor Xa or thrombin inhibitors) that need no routine lab monitoring.

Apixaban (Eliquis)

Oral factor Xa inhibitor for AFib and DVT/PE; antidote: andexanet alfa.

Rivaroxaban (Xarelto)

Once-daily factor Xa inhibitor used for VTE prevention/treatment; take with evening meal ≥15 mg doses.

Dabigatran (Pradaxa)

Direct thrombin inhibitor; causes bleeding and dyspepsia; antidote: idarucizumab.

Andexanet alfa (Andexxa)

Recombinant decoy factor Xa that reverses apixaban or rivaroxaban bleeding.

Idarucizumab (Praxbind)

Monoclonal antibody fragment that neutralizes dabigatran within minutes.

Alteplase (tPA)

Thrombolytic enzyme that converts plasminogen to plasmin; used for acute ischemic stroke within 3–4.5 h.

Platelet Plug

Primary hemostatic aggregation of platelets at injury site; target of antiplatelet drugs.

Coagulation Cascade

Sequential activation of clotting factors leading to fibrin; inhibited by anticoagulants.

Fibrinolysis

Enzymatic breakdown of fibrin clot by plasmin; enhanced therapeutically by thrombolytics.

Antiplatelet Drugs

Medications (aspirin, P2Y12 inhibitors) that prevent arterial thrombosis by inhibiting platelet activation.

P2Y12 Inhibitors

Clopidogrel, ticagrelor block ADP receptors on platelets; used with aspirin after stenting.

Clopidogrel

Prodrug P2Y12 inhibitor; prevents stent thrombosis; stop 5 days before surgery if possible.

Ticagrelor

Reversible P2Y12 inhibitor causing dyspnea; faster onset than clopidogrel.

Protamine Sulfate

Positively charged antidote that neutralizes heparin’s anticoagulant effect.

Vitamin K (Phytonadione)

Reversal agent for warfarin-induced bleeding; restores synthesis of clotting factors.

aPTT

Activated partial thromboplastin time; lab test to monitor unfractionated heparin therapy.

Ferrous Sulfate

Oral iron salt for iron-deficiency anemia; best on empty stomach; black stools common.

Folic Acid (Vitamin B9)

Water-soluble vitamin treating macrocytic anemia and preventing neural tube defects.

Cyanocobalamin (Vitamin B12)

Supplement for pernicious anemia; often given IM due to intrinsic factor deficiency.

Plasmin

Enzyme that degrades fibrin into soluble fragments during clot lysis.

von Willebrand factor (vWF)

Glycoprotein that mediates platelet adhesion and stabilizes factor VIII in primary hemostasis.