Prothrombin complex concentrates.

The use of the prothrombin complex products for the treatment of inhibitor patients is discussed in relation to our difficulty in identifying the effective therapeutic principle, as well as the factors responsible for thrombogenicity. It would appear that combination of factors is responsible for either or both therapeutic and thrombogenic phenomena. Possible intermediate or aggregate forms of the procoagulants are present in the products, protected from the neutralizing effects of antithrombin III.