VPT 311: General and Systemic Veterinary Pharmacology (2+1)

COAGULANTS

• Coagulants are agents that promote coagulation of blood. Various coagulants used are

Thromboplastin

• Thrombopalstin (thrombokinase) is produced naturally by platelets and damaged tissue.
• Commercial thromboplastin is an extract of cattle brain in normal saline.
• It is applied locally as a haemostatic in capillary oozing, in the treatment of epistaxis.

Thrombin

• Thrombin is an enzyme, which converts fibrinogen into fibrin.
• Bovine thrombin is a powder supplied with suitable diluent.
• It is used in arresting capillary haemorrhage and in conjunction with fibrinogen or fibrin foam for this purpose.

Fibrinogen

• Fibrinogen is used in assisting the adhesion of grafts of skin and mucous membrane as a 2% solution.

Fibrin

• Fibrin is available as fibrin foam in the form of strips of a fine white sponge.
• These strips are soaked in thrombin solution and placed over the site of haemorrhage or in the cavity. Coagulation occurs immediately.

Oxidised cellulose

• It should be applied dry and when it swells forms a brown gelatinous mass which may take about 7 days or more to be absorbed.

Calcium alginate

• This consists of calcium or a mixture of calcium and sodium alginates.
• It is an absorbable haemostatic.

Absorbable gelatin sponge

• This is prepared from gelatin and treated with formaldehyde, heated, whisked into a foam and freeze dried.
• This sponge is insoluble in water, but can be wetted.
• Miscellaneous local haemostatics include strong solution of ferric chloride, alum and tannic acid.
  • Fresh blood or plasma
  • Vitamin K
    • Vitamin K1 (from plants, fat soluble) – Phytonadione
    • Vitamin K2 (produced by bacteria) – Meanquinone
    • Vitamin K3 – (i) Fat soluble – Menadione
    • Water soluble – Menadione sodium bisulfite, Menadione sodium diphosphate
  • Miscellaneous
    • Fibrinogen
    • Antihaemophilic factor
    • Tissue extract
    • Adrenochrome monosemicarbazone
    • Rutin
    • Ethamsylate