Factor VIII (human)

Factor VIII (human) Uses, Dosage, Side Effects, Food Interaction and all others data.

Factor VIII is required for clot formation and maintenance of haemostasis. It activates factor X in conjunction with activated factor IX. Activated factor X then converts prothrombin to thrombin, which converts fibrinogen to fibrin, and forms a stable clot with factor XIII. Factor VIII is used for replacement therapy in patients with haemophilia A.

The human antihemophilic factor assists in the convertion of prothrombin to thrombin. Its administration generates the formation of a complex constituted by the Factor IXa, Factor X and the antihemophilic factor which triggers the normal coagulation cascade for the formation of blood clots. The human antihemophilic factor is increased in the plasma thus enabling temporary correction of the hemophilia A bleeding. Its effect is reported as the normalization of the partial thromboplastin time.

Factor VIII (human)
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	Factor VIII (human)
Generic	Antihemophilic factor human
Antihemophilic factor human Other Names	Antihemophilic factor VIII human, Antihemophilic factor, human, Antihemophilic factor, human (monoclonal), Antihemophilic factor,human, F8 protein, human, Factor VIII (antihaemophilic factor), Factor VIII (human), factor VIII, human, Human coagulation factor VIII
Type
Weight	480000.0 Da (active (coagulant activity))
Protein binding	The human antihemophilic factor is retained mainly in the blood as its major function is to start the coagulation cascade.
Groups	Approved
Therapeutic Class	Antihaemophilic factor
Manufacturer
Available Country
Last Updated:	September 19, 2023 at 7:00 am

Uses

Treatment and prophylaxis of haemorrhagic episodes in patients with haemophilia A, Prophylaxis in severe haemophilia A

Factor VIII (human) is also used to associated treatment for these conditions: Hemorrhagic episodes

How Factor VIII (human) works

The human antihemophilic factor replaces the coagulation factor VIII. It acts as a co-factor for factor IX to activate factor X in the intrinsic pathway of blood coagulation.

Dosage

Factor VIII (human) dosage

Intravenous (Adult)-

Treatment and prophylaxis of haemorrhagic episodes in patients with haemophilia A:Dosage is individualised based on coagulation tests performed before treatment and at regular intervals during treatment. Generally, 1 IU/kg will increase circulating factor VIII levels by about 2 IU/dL. Recommended doses vary according to the preparation used.

Suggested doses: Mild-moderate haemorrhage (increase to 20-30% of normal): Usually with a single dose of 10-15 IU/kg;

More serious haemorrhage or minor surgery (increase to 30-50% of normal): Usual initial dose of 15-25 units/kg followed by 10-15 IU/kg every 8-12 hr if required;

Severe haemorrhage or major surgery (increase to 80-100% of normal): Usual initial dose of 40-50 IU/kg followed by 20-25 IU/kg every 8-12 hr. Refer to individual product information for further dosing details.

Prophylaxis in severe haemophilia A:10-50 IU/kg every 2-3 days, as needed.

Intravenous: Treatment and prophylaxis of haemorrhagic episodes: If refrigerated, warm dried concentrate and diluent to room temperature before reconstitution.

Side Effects

Allergic reactions e.g. chills, chest tightness, fever, headache, hyperfibrinogenaemia, jittery feeling, lethargy, nausea, vomiting, somnolence, stinging at infusion site, stomach discomfort, tingling, urticaria, vasomotor reactions with rapid infusion.

Toxicity

The highest toxicity is the risk of viral hepatitis transmition as well as intravascular hemolyisis can occur if large or frequent doses are used in blood groups A, B or AB.

Precaution

Risk of intravascular haemolysis in patients with blood groups A, B, or AB receiving high doses or repeated doses of factor VIII preparations. Risk of transmission of some viral infections especially hepatitis B and C. Dose requirement may vary in patients with factor VIII inhibitors; thus optimal treatment should be based on clinical response. Monitor platelet counts regularly during treatment.

Interaction

Food Interaction

No interactions found.

Volume of Distribution

The pharmacokinetic profile of the human antihemophilic factor needed to be studied by the two-compartment theory as not all of it stays just in blood plasma. The central and peripheral volume of distribution in adults weight an average of 68 kg were 2.81 L and 1.90 L respectively.

Elimination Route

After intravenous administration of the human antihemophilic factor the values of Cmax, AUC and Tmax were 100 IU/ml, 1450 IU h/ml and 0.43 h respectively. In a second clinical trial, the treatment was administered for six months and the values of Cmax, AUC and Tmax were 99 units/ 100 ml, 1471 units h/ 100ml and 16 h, respectively.

Half Life

The mean half-life of human antihemophilic factor administered in hemophilic A patients is 14.8 hours.

Clearance

The reported clearance for the administration of antihemophilic factor is 0.15 L/h in adults with an average weight of 68 kg. In the same study, there was a separation of the intercompartment clearance which is 0.16 L/h. The clearance rate was reported to be significantly decreased with increasing age and significantly increased in patients that presented a blood type of gourp O.

Elimination Route

Intravenous administration of human antihemophilic factor is rapidly eliminated primarly through the reticuloendothelial system.

Pregnancy & Breastfeeding use

Pregnancy Category C. Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus.