Active Ingredients

Aprotinin – Effect, Application & Risks


Aprotinin is an antifibrinolytic and as such has an inhibiting effect on the splitting of the protein fibrin (i.e. on fibrinolysis ). Because of this property, it occurs in tissue adhesives . Indications include coronary artery bypass surgery and the very rare alpha2-antiplasmin deficiency, which is genetic. Because of the possible risks of aprotinin, the active substance is only approved in Germany under certain conditions.

What is aprotinin?

Aprotinin is a drug from the group of antifibrinolytics. The name of this group of substances goes back to the enzyme fibrinolysin, which is better known today as plasmin .

Medicine also refers to the process of fibrin cleavage by the enzyme plasmin, which is a serine protease, as fibrinolysis. A temporary inhibition of plasmin is possible with aprotinin, among other things, since the active substance binds reversibly to the enzyme and deactivates it. However, the plasmin remains intact and can become active again later.

Aprotinin occurs naturally in the lungs of cattle. The pharmacological production of the active ingredient is based on the fermentation of that tissue. A filtration then frees the substance from superfluous components. A special gel is used to help clean the fermented bovine lung tissue.

Pharmacological action

Aprotinin is found in tissue glue. Medicine also knows it as fibrin glue and uses it in surgery to seal layers of tissue or wound edges. Two components are required, with aprotinin being component 1. Other active substances of this component are fibrinogen and factor XIII, the production of which is based on the fractionation of human blood plasma .Thrombin , which belongs to component 2 of the tissue adhesive and is initially present there in the form of the precursor prothrombin , also goes back to this raw material . Component 2 also includes calcium chloride or calcium chloride dihydrate, which provides the needed calcium ions.

When used surgically, the various active ingredients interact with each other: prothrombin converts to thrombin and thus becomes enzymatically active. It then splits the coagulation factor fibrinogen into fibrin and activates factor XIII. This in turn weaves the individual fibrinomers into a network that the human body can break down itself.

The advantage is that the fibrin glue can also connect tissue that would be difficult to access for later pulling of sutures after suturing. In this context, the task of aprotinin is to inhibit the body’s own enzyme plasmin and to slow down its function. Plasmin splits fibrin and could thus loosen the glued tissue again prematurely.

Medical Application & Use

Aprotinin can be used, for example, in an operation to create a coronary artery bypass. Such a bypass is an artificial circumvention of the blood vessel . The aim is to allow blood to flow despite a narrowing of the affected coronary artery .

The bypass can bypass both an artery and a vein . Medicine also refers to this clinical picture as coronary stenosis, which often occurs as part of coronary heart disease . However, a bypass is not necessary or possible in every case. For the surgical treatment of the narrowing, a stent can also be considered, for example, in which a tube as an endoprosthesis in the blood vessel is intended to ensure the flow.

Doctors used to use aprotinin to stop bleeding when the bleeding was due to increased fibrinolysis (hyperfibrinolysis). Today, however, this procedure is no longer common, since aprotinin is associated with risks that only make its use sensible under very specific conditions.

However, aprotinin is still indicated in alpha2-antiplasmin deficiency. This is a deficit of the serine protease inhibitor. The inhibitor binds to plasmin, thereby deactivating it. A deficiency can therefore result in primary hyperfibrinolysis.

Alpha2-antiplasmin is produced in healthy people in the right amount in the liver . The body can synthesize it itself. Alpha2-antiplasmin deficiency is extremely rare, with only a few reported cases, and is primarily due to a corresponding genetic predisposition, which is inherited in an autosomal recessive manner .

For all indications that come into consideration for the use of aprotinin, it is necessary to weigh up individual factors that influence the cost-benefit ratio in the individual case.

Risks & side effects

Aprotinin temporarily lost its approval in Germany between 2007 and 2013 because a 2006 study indicated a possible increase in the risk of kidney failure . The renewed approval was accompanied by stricter conditions.Hypersensitivity to bovine proteins is a contraindication to the use of aprotinin, since the active substance is a bovine organism polypeptide and originates from the animal’s lungs.

Aprotinin side effects include anaphylactic reactions, as well as various allergic reactions . The latter manifest themselves primarily as itching and pathological skin changes (efflorescences).

Bradycardia may occur , in which the heart rate slows and falls below the rough limit of 60 beats per minute, which is considered the adult reference.

Aprotinin can also trigger bronchospasm . This manifests itself in cramping of the bronchial muscles, which may result in an increase in airway resistance.

Chills and hypertension (high blood pressure) are also undesirable side effects of aprotinin. Bruising (hematoma) and edema can also form. The latter are characterized by increased accumulation of fluid in the tissues.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.