Using your solution in Question 11, estimate how much Macken…
Using your solution in Question 11, estimate how much Mackenzie Enterprises’s profit changes if the production constraint increases to 105 units. Include a description of this change (size and direction) in words. Solutions that re-solve the Lagrangian Function will not be considered.
Using your solution in Question 11, estimate how much Macken…
Questions
Using yоur sоlutiоn in Question 11, estimаte how much Mаckenzie Enterprises's profit chаnges if the production constraint increases to 105 units. Include a description of this change (size and direction) in words. Solutions that re-solve the Lagrangian Function will not be considered.
WHAT CERVICAL LENGTH MAKES IT MORE LIKELY THAT THE PATIENT WILL SUFFER FROM PRETERM DELIVERY?
WHAT VIEW SHOULD BE USED TO EVALUATE A 3 VESSEL CORD?
Direct Thrоmbin (IIа) Inhibitоrs (DTIs) Overview Drug Clаss: Direct thrоmbin (Fаctor IIa) inhibitors Examples: Dabigatran (oral), Argatroban (IV), Bivalirudin (IV) Target: Free + clot-bound thrombin Core effect: Prevent fibrin formation → inhibit clot formation Mechanism of Action Direct inhibition of thrombin (Factor IIa) Blocks conversion: fibrinogen → fibrin Inhibits thrombin-mediated platelet activation Works on both circulating and clot-bound thrombin (key advantage over indirect agents) Pharmacokinetics Parenteral (IV): Argatroban, Bivalirudin → acute anticoagulation Oral (DOAC): Dabigatran etexilate → chronic anticoagulation No routine coagulation monitoring required Pregnancy: contraindicated (all agents in class) Pharmacodynamics Rapid anticoagulant effect (IV agents: minutes) Dabigatran onset: ~1–2 hours Duration varies: IV short; dabigatran long (~22 hrs) High bleeding risk limits therapeutic index No routine lab monitoring despite potent effect Indications Dabigatran: VTE prevention and treatment (DVT, PE) Stroke prevention in non-valvular atrial fibrillation Argatroban / Bivalirudin: Acute coronary syndromes (ACS), especially during PCI Heparin-induced thrombocytopenia (HIT) Alternative to unfractionated heparin in high-risk settings Adverse Effects Primary: bleeding (all agents) Dabigatran boxed warnings: Thrombotic events if abruptly discontinued Epidural/spinal hematoma risk No heparin-induced thrombocytopenia (HIT) with DTIs High anticoagulant potency → hemorrhage risk is limiting toxicity Contraindications & InteractionsArgatroban: Hepatic metabolism → contraindicated in severe hepatic dysfunction Bivalirudin: Renal excretion → dose adjustment in severe renal impairment Dabigatran: Contraindicated in severe renal dysfunction P-gp substrate interactions: P-gp inhibitors (e.g., calcium channel blockers) → ↑ absorption → ↑ bleeding risk P-gp inducers (e.g., rifampin) → ↓ absorption → ↑ stroke risk Antidote/reversal agent: Idarucizumab mAb [Praxbind] Other AEs Risk of thrombotic events with early stop ….. boxed warning Risk of epidural or spinal hematoma ……….. boxed warning Question: A 67-year-old man is brought to the cardiac catheterization lab for percutaneous coronary intervention (PCI) due to an acute coronary syndrome. His medical history is significant for heparin-induced thrombocytopenia (HIT) and severe chronic liver disease with elevated liver enzymes and reduced synthetic function. The interventional cardiologist plans to use an anticoagulant during the procedure. Which of the following is the most appropriate anticoagulant for this patient?
Vitаmin K Antаgоnist: Wаrfarin Mechanism оf Actiоn Inhibits vitamin K epoxide reductase ↓ activation of vitamin K → ↓ synthesis of: Clotting factors: II, VII, IX, X Protein C & S (natural anticoagulants) Early effect: ↓ Protein C/S first → transient hypercoagulable state (1–2 days) Requires heparin bridging initially Antidote Vitamin K Pharmacokinetics Oral administration High protein binding → drug displacement interactions Long half-life: 36–42 hours Duration: 2–5 days Hepatic metabolism: CYP2C9 Excretion: urine Crosses placenta → teratogenic (contraindicated in pregnancy) Monitoring: INR (key test) Drug Interactions ↑ Warfarin effect (↑ bleeding) CYP2C9 inhibitors (e.g., azoles like ketoconazole) Protein-binding displacement: Aspirin Sulfonamides Reduced gut flora (broad-spectrum antibiotics → ↓ vitamin K) ↓ Warfarin effect (↓ anticoagulation) CYP inducers (e.g., rifampin) High vitamin K intake Clinical Uses Chronic anticoagulation for: DVT PE Atrial fibrillation (stroke prevention) MI / ACS Stroke / TIA prevention Heart failure (selected cases) Prosthetic heart valves (key indication) Adverse Effects Major Bleeding (highest risk among oral anticoagulants) Key toxicities Skin necrosis (protein C depletion early) Teratogenicity (fetal warfarin syndrome) Calciphylaxis (vascular calcification) Purple toe syndrome (cholesterol embolization; rare) Question: A 62-year-old man with a history of deep vein thrombosis is started on warfarin therapy. Three days later, he presents with painful, erythematous plaques on his thighs that have progressed to areas of skin necrosis. Laboratory studies show a therapeutic INR. Which of the following is the most likely mechanism responsible for this patient’s condition?
THROMBOLYTICS OverviewStreptоkinаse; Alteplаse (Activаse); Reteplase (Retavase); Tenecteplase (TNKase) Mechanism оf ActiоnActivate plasminogen → plasminPlasmin degrades fibrin mesh → clot lysis → vessel reperfusionFibrin-specific agents bind fibrin-bound plasminogen → localized clot breakdownOlder clots are more resistant due to fibrin stabilization PharmacokineticsAlteplase, reteplase, tenecteplase: IV or catheter-directedHepatic metabolism (primarily)Urinary excretion of metabolitesShort onset (~30 min effect window for reperfusion activity)Tenecteplase and reteplase have longer half-lives → bolus dosing advantage PharmacodynamicsRapid fibrinolysis of formed thrombi (not prevention)High specificity agents limit systemic plasmin activationTherapeutic effect depends on clot age (early use most effective) IndicationsAcute myocardial infarction (MI)Acute ischemic stroke (time-sensitive)Venous thromboembolism (PE, selected DVT)Occluded catheters (dialysis, central lines)Adjunct in thrombosis management when anticoagulants insufficient aloneBest outcomes when given early (≤ ~6 hours from onset; stroke often narrower window clinically) Adverse EffectsCommon: Bleeding (most important and dose-limiting)Serious: Intracranial hemorrhageThromboembolism from clot fragmentationReperfusion injury (tissue damage after restoring flow) Contraindications & InteractionsAbsolute concern: any active bleedingRecent GI bleedIntracranial hemorrhage, tumor, aneurysmRecent intracranial/spinal/eye surgery or traumaHemorrhagic stroke historyAortic dissectionSevere uncontrolled hypertensionPregnancy (relative/clinical-risk dependent contexts) Question: A 72-year-old woman is brought to the emergency department 90 minutes after sudden onset of right-sided weakness and expressive aphasia. Non-contrast head CT shows no intracranial hemorrhage. Blood pressure is 168/92 mmHg. Past medical history is significant for an intracerebral hemorrhage 6 months ago. She is otherwise stable and is being evaluated for IV alteplase therapy. Which of the following is the most appropriate next step?