Vitamin K Treatment for Bleeding

Vitamin K Treatment of Bleeding

• Vitamin K is a fat-soluble vitamin.
• Two forms exist: Vitamin K1 (phylloquinone) and Vitamin K2 (menaquinone).
• Vitamin K1 is found in food, while Vitamin K2 is found in human tissues and synthesized by intestinal bacteria.
• Both Vitamin K1 and K2 require bile salts for absorption from the intestines.
• Vitamin K is available in oral and parenteral (injectable) forms.
• Onset of effect is delayed for 6 hours, but complete effect is seen within 24 hours.
• Used to treat reduced prothrombin activity caused by excess warfarin or Vitamin K deficiency.
• Intravenous administration must be slow to prevent dyspnea, chest/back pain, and even death.

Mechanism of Action

• Vitamin K is crucial for the final stage of synthesis of 6 clotting factors in the liver.
• This involves γ-carboxylation of glutamic acid residues in factors 2, 7, 9, and 10, and anticoagulant proteins S and C.

Vitamin K Preparations

• Phytomenadione (Vitamin K1): Acts within 12 hours, and intravenous formulations are used in emergencies.

Menaquinone (Vitamin K2)

• Menaquinone-7 is a form of Vitamin K2.
• It is water-soluble and doesn't require bile salts for absorption, making it preferred in malabsorption syndromes.
• However, it takes 24 hours to act, so it isn't used for treating warfarin overdose.
• It may cause hemolytic anemia, so it is avoided in neonates, especially those with G6PD deficiency.

Menadiol Sodium Phosphate (Vitamin K3)

• Water-soluble, and doesn't need bile salts for absorption.
• Preferred in conditions with malabsorption.
• Takes 24 hours to act, not used to treat warfarin overdose.
• Can cause hemolytic anemia, so it's not recommended for neonates, especially those with G6PD deficiency.

Indications for Vitamin K Therapy

• Hemorrhage due to coumarin anticoagulants
• Hemorrhagic disease of the newborn
• Hypoprothrombinemia (due to malabsorption)
• Vitamin K deficiency (frequently seen in hospitalized patients with poor diet, parenteral nutrition, recent surgery, multiple antibiotic therapy, and uremia).
• Blood transfusion may be used for severe hemorrhage.

Aminocaproic Acid and Tranexamic Acid

• Both are synthetic, orally active, and excreted in the urine
• Inhibit plasminogen activation.
• Tranexamic acid is 10 times more potent than aminocaproic acid.
• Potential side effect: intravascular thrombosis

Bleeding Due to Idiopathic Thrombocytopenic Purpura (ITP)

• Corticosteroids are a first-line treatment.
• Rho (D) immune globulin (Human; Anti-D): mechanism of action isn't fully understood.
• Immunosuppressants (like Azathioprine)
• Mycophenolate mofetil
• Intravenous immunoglobulin (IVIg)
• Thrombopoietin receptor agonists (Romiplostim and Eltrombopag): stimulate platelet production in the bone marrow.

Dapsone

• Anti-infective sulfone drug used as a second-line treatment for ITP.

Rituximab

• Chimeric monoclonal antibody against the B-cell surface antigen CD20.
• Alternative treatment to splenectomy.

Protamine Sulfate

• Antagonizes the anticoagulant effects of heparin.
• Potentially causes hypersensitivity, dyspnea, flushing, bradycardia, and hypotension when injected rapidly. -Contraindicated in patients with DIC or genitourinary bleeding of the upper tract.

Explore the role of Vitamin K in treating bleeding conditions. Learn about its forms, mechanism of action, and preparations used in clinical settings. This quiz covers essential information on the administration and effects of Vitamin K.