(4.1) ANTICOAGULATION CASE STUDY - DR. SKINNER

Anticoagulation Case Study: Riding the Struggle Bus

• Course: BMS 551 Med Phys Pharm
• Instructor: Brian Skinner, PharmD, BCPS
• Institution: Marian University – Wood College of Osteopathic Medicine
• Term: Fall 2024

Objectives

• Relate patient medical history, diagnosis, and treatment to medical physiology and pharmacology.
• Identify risk factors for thrombus development.
• Identify contraceptive products contraindicated in patients with hypercoagulable disorders.
• Identify steps in fibrin clot formation, including extrinsic, intrinsic, and common pathways.
• Examine pregnancy's effect on pharmacotherapy selection and identify appropriate anticoagulants for patients.

Agenda

• Clinical Case: Patient presentation, pathophysiology of disease, future issues, treatment of disease.
• Conclusion: Impact on student practice. Discussion of learning points.

Patient: Sandie Lynn Kris (18 yo female)

• Social History: College freshman, flute player in marching band, not sexually active, denies alcohol, tobacco, illicit drugs.
• Past Medical History: Dysmenorrhea, acne.
• Medications: Yaz® (ethinyl estradiol & drospirenone).
• Travel History: Recent 5-hour bus trip to another college for a football game with the marching band.

Patient Case: Presentation

• Chief Complaint: Swelling and pain in left lower extremity.
• Imaging: Ultrasound reveals a thrombus in the great saphenous vein of the left leg.
• Genetic Testing:
  • Prothrombin Gene Mutation: Negative
  • Antithrombin III Deficiency: Negative
  • Protein C Activity: Normal
  • Factor V Leiden: Positive (heterozygous)

Virchow's Triad in Action

• Circulatory Stasis: Immobility, venous obstruction (e.g., obesity, pregnancy, tumor), varicose veins, atrial fibrillation.
• Endothelial Injury: Trauma, atherosclerosis, venepuncture.
• Hypercoagulability: Surgery, malignancy, pregnancy, estrogen therapy, inherited thrombophilia.

Clotting Cascade (Simplified)

• Intrinsic Pathway (aPTT): XII, XI, IX, VIII, X.
• Extrinsic Pathway (PT): VII, X.
• Common Pathway (aPTT & PT): V, II, Fibrin Clot, XIII.

Clotting Cascade (Full)

• Includes details of the contact activation and tissue factor pathways, key factors like thrombin, as well as the roles of protein C and protein S.

Birth Control and Thrombus Formation

• Estrogen-containing oral contraceptives affect gene transcription factors of proteins (II, VII, X, XII, XIII, and fibrinogen).
• Progestins were added to decrease estrogen in OCPs. Drospirenone and desogestrel are novel progestins with antimineralocorticoid and antiandrogenic properties.
• Increased blood clot risk by 1.5-fold compared to other progestins.

Venous System of the Legs

• Diagram of the superficial and deep venous systems of the legs, including the sapheno-femoral junction and communicating veins.

Treatment

• Warm compress of the affected area.
• NSAIDs as needed for pain.
• Discontinue estrogen-containing oral contraceptives.
• Use progestin-only pill, progestin IUD, progestin implant, or copper IUD.

Treatment Plan

• Enoxaparin until week 36.
• Switched to heparin until week 39.
• Planned induction for 39+1 weeks.
• Placed back on enoxaparin 24 hours after delivery x 6 weeks.

Medications to Treat Thrombotic Disorders

• Injectable Formulations: Heparin Products: heparin, low-molecular-weight heparins (enoxaparin, dalteparin). Factor Xa Inhibitors: rivaroxaban, apixaban, betrixaban, edoxaban, fondaparinux.
• Oral Formulations: Direct Thrombin Inhibitors (Factor II): dabigatran, argatroban, bivalirudin. Vitamin K Antagonists: warfarin.

Thromboprophylaxis During Pregnancy

• Heparin dosages, route of administration (subcutaneous), half-life, and factors inhibited.
• Enoxaparin dosages, route of administration (subcutaneous), half-life, and factors inhibited.
• 3rd Trimester vs 1st and 2nd Trimester dosing considerations.
• Injection site locations.

Impact on Me and My Practice

• As a healthcare provider, it can be challenging to be a patient/patient's family member.
• Implementation of care is more complex than simply prescribing medication.

What Can We Learn?

• Chronic conditions, even without explicit treatment requirements, are still chronic.
• Understanding disease pathophysiology is vital to identifying at-risk patients.
• Managing conditions during pregnancy adds the challenge of ensuring both maternal and fetal safety and efficacy of therapy.

MPP Patient Podcast Project

• Podcast by Tanner Maxfield providing further patient perspective.
• URL provided for podcast.