Coagulants are substances which promote coagulation, and are indicated in haemorrhagic states.
Fresh whole blood or plasma provide all the factors needed for coagulation and are the best therapy for deficiency of any clotting factor; also they act immediately. Other coagulants drugs used to restore haemostasis are:
- Vitamin K
K1 (from plants, fat-soluble) Phytonadione (Phylloquinone)
K2 (synthetic)
–Fat-soluble : Menadione, Acetomenaphthone
–Water-soluble : Menadione sod. bisulfite Menadione sod. diphosphate
- Miscellaneous
- Fibrinogen (human)
- Antihaemophilic factor
- Desmopressin
- Adrenochrome Monosemicarbazone
- Rutin
- Ethamsylate
VITAMIN K
It is a fat-soluble dietary principle required for the synthesis of clotting factors.
Without vitamin K, blood coagulation is seriously impaired, and uncontrolled bleeding occurs. Preliminary clinical research indicates that deficiency of vitamin K may weaken bones, potentially leading to osteoporosis, and may promote calcification of arteries and other soft tissues.
Vitamin K1, also known as phylloquinone or phytomenadione, is made by plants, and is found in highest amount in green leafy vegetables because it is directly involved in photosynthesis. It may be thought of as the plant form of vitamin K. It is active as a vitamin in animals and performs the classic functions of vitamin K, including its activity in the production of blood-clotting proteins.
Deficiency=
Deficiency of Vit K occurs due to liver disease, obstructive jaundice, malabsorption, long-term antimicrobial therapy which alters intestinal flora. However, deficient diet is rarely responsible.
The most important manifestation is bleeding tendency due to lowering of the levels of prothrombin and other clotting factors in blood.
Haematuria is usually first to occur; other common sites of bleeding are git., nose and under the skin—ecchymoses.
Preparations=
- Phytonadione
Phytomenadione, also known as vitamin K1 or phylloquinone, is a vitamin found in food and used as a dietary supplement. As a supplement it is used to treat certain bleeding disorders.
This includes in warfarin overdose, vitamin K deficiency, and obstructive jaundice. It is also recommended to prevent and treat vitamin K deficiency bleeding in infants. Use is typically recommended by mouth or injection under the skin. Use by injection into a vein or muscle is recommended only when other routes are not possible. When given by injection benefits are seen within two hours.
- Menadione
Menadione is an organic compound with the formula C6H4(C0)2C2H(CH3). It is an analog of 1,4-naphthoquinone with a methyl group in the 2-position. It is occasionally used as a nutritional supplement in animal feed because of its vitamin K activity.
- Acetomenaphthone
Acetomenaphthone, a vitamin K analogue used to treat and prevent hypoprothrombinemia caused by vitamin K deficiency. Also called menadiol diacetate.
- Menadione sod. bisulfite
Menadione sodium bisulfite is a water soluble form of menadione, which belongs to the Vitamin K class of compounds. These are necessary for the biosynthesis of prothrombin and other blood clotting factors. Menadione is a prothrombotic compound and is used as a model quinone in cell culture and in vivo investigations.
Uses=
The only use of vit K is in prophylaxis and treatment of bleeding due to deficiency of clotting factors in the following situations:
- Dietary deficiency of vit K is very rare in adults. However, when it occurs 5–10 mg/day oral or parenteral vit K rapidly corrects the defects.
- Prolonged antimicrobial therapy: treat in the same way as dietary deficiency of vit K.
- Obstructive jaundice or malabsorption syndromes (sprue, regional ileitis, steatorrhoea, etc.): vit K 10 mg i.m./day, or orally along with bile salts.
FIBRINOGEN
The fibrinogen fraction of human plasma is employed to control bleeding in haemophilia, anthem philic globulin (AHG) deficiency and acute afibrinogenemia states; 0.5 g is infused i.v. FIBRINAL 0.5 g/bottle for i.v. infusion.
ANTIHAEMOPHILIC FACTOR
It is concentrated human AHG prepared from pooled human plasma. It is indicated (along with human fibrinogen) in haemophilia and AHG deficiency.
It is highly effective in controlling bleeding episodes, but action is short-lasting (1 to 2 days).
Dose: 5-10 U/kg by i.v. infusion, repeated 6-12 hourly
DESMOPRESSIN
It releases factor VIII and von Willebrand’s factor for vascular endothelium and checks bleeding in haemophilia and von Willebrand’s disease.
ADRENOCHROME MONOSEMICARBAZONE
It is believed to reduce capillary fragility, control oozing from raw surfaces and prevent microvessel bleeding, e.g. epistaxis, haematuria, secondary haemorrhage from wounds, etc. Its efficacy is uncertain.
Dose: 1-5 mg oral, i.m.
RUTIN
It is a plant glycoside claimed to reduce capillary bleeding. It has been used in a dose of 60 mg oral BD TDS along with vit C which is believed to facilitate its action. Its efficacy is uncertain.
ETHAMSYLATE
It reduces capillary bleeding when platelets are adequate; probably exerts antihyaluronidase action or corrects abnormalities of platelet adhesion, but does not stabilize fibrin (not an antifibrinolytic).
Ethamsylate has been used in the prevention and treatment of capillary bleeding in menorrhagia, after abortion, PPH, epistaxis, malena, hematuria and after tooth extraction, but efficacy is unsubstantiated. Side effects are nausea, rash, headache, and fall in BP (only after i.v. injection).
