Canterbury DHB

Mild Haemophilia

Use non-blood product treatment with desmopressin for minor bleeds and minor surgical procedures in mild-to-moderate haemophilia A and von Willebrand Disease.

Desmopressin

Desmopressin is a synthetic analogue of the antidiuretic hormone Vasopressin. It is an established treatment for mild haemophilia and von Willebrand Disease (VWD) and releases FVIII:C and VWF from endothelial storage sites. VWF and VWC levels increase 3 to 4 times following desmopressin and in VWD, the bleeding time is minimally shortened. The effect may last for 12 to 24 hours, but patients may become unresponsive to desmopressin after 2 to 3 days if more than two doses are given within a 2 to 3 day period. Responsiveness to desmopressin may return in 2 to 3 days after discontinuation.

See the Desmopressin Data Sheets on Medsafe for dosage, precautions, side effects and contraindications. In particular, beware of the potential for desmopressin to cause hyponatraemia, especially if a repeated dose is given. Restrict fluids to the minimum necessary for 24 to 48 hours after dosing.

Haemophilia A

Desmopressin is especially useful in patients with mild haemophilia who have a baseline FVIII:C > 10%. A three-fold rise in factor VIII:C after desmopressin enables a factor VIII target level of at least 30% to be achieved, which is sufficient for normal haemostasis in minor surgical procedures. In both mild and more moderately severe haemophiliacs, the use of desmopressin may be useful as an adjuvant therapy with factor VIII concentrate to achieve adequate haemostasis. It is recommended that a desmopressin trial is carried out before surgery to assess the response, because some individuals respond poorly to treatment. Do not do a desmopressin trial within four days of planned surgery.

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Factor VIII Concentrates

For more major bleeding episodes or surgery in patients with mild haemophilia, target factor levels should be similar to those recommended for severe or moderate deficiency patients. In the majority of mildly deficient factor VIII patients, especially those who are previously untreated, recombinant factor VIII is the product of choice.

Note: Beware of the high potential risk for mild haemophilia A patients to develop inhibitory antibodies at times of high antigen exposure (e.g. approximately 10,000 units per treatment episode or period).

Topic Code: 5264