Pathophysiological rationale for use
Under normal body functioning, enzyme activation occurs in the intestinal lumen. However, in pathological conditions, secretion outflow is impaired. Causes of such duct obstruction may include acute pancreatitis, exacerbation of a chronic process, trauma, pancreatic cancer, or edema of the duodenal wall (e.g., after alcohol intake).
Amidst secretion stagnation, a specific enzyme is activated — cytokinase. It triggers a pathological cascade: proenzymes convert into active forms directly within the gland's tissues. The process of autolysis begins — rapid self-digestion of the pancreas and its surrounding structures.
Pharmacodynamics and therapeutic effects
The action of antienzyme drugs is aimed at the emergency suppression of pancreatic enzyme activity. Their mechanism of action consists of two key processes:
- Inactivation of trypsin already circulating in the systemic bloodstream.
- Blocking free kinins — crucial mediators responsible for the development of the inflammatory response and pain syndrome.
Due to this, pronounced therapeutic effects are achieved: toxemia is eliminated, and the destructive process (necrosis) in the glandular tissues ceases to progress.
Characteristics of main drugs
In clinical practice, agents capable of inhibiting a wide range of proteases are used.
- Pantripin (Pantripinum). It is a polypeptide obtained by extraction from the pancreas of cattle. It specifically binds and inhibits enzymes such as trypsin, chymotrypsin, kallikrein, and plasmin. Because the drug contains foreign animal protein, it carries a high risk of developing allergies and is strictly contraindicated in case of individual intolerance.
- Aprotinin (drugs Gordox, Contrykal). In its mechanism of action, it is completely analogous to pantripin. In addition to inhibiting proteolytic enzymes, aprotinin reduces the fibrinolytic activity of the blood. This provides an additional hemostatic effect. Because of this property, the drug is strictly contraindicated in patients with increased blood clotting (hypercoagulation).
Administration principles and precautions
To achieve a pronounced antienzyme effect, sufficiently high doses of drugs are required. They are administered exclusively intravenously via a drip method. Either a 5% glucose solution or a 0.9% sodium chloride solution is used as a diluent.
A critically important step before starting the infusion is mandatory determination of individual tolerance. Due to the protein nature of proteolysis inhibitors, the risk of allergic reactions is extremely high, especially in patients with a burdened allergic history.
The rule of two "P"s will help remember the effects of aprotinin: it Suppresses Proteases (saving the pancreas from necrosis) and Suppresses Plasmin (stopping bleeding by reducing fibrinolytic activity).
Class and exam questions
Why do enzymes activate inside the gland during pancreatitis?
Due to impaired secretion outflow (edema, trauma, obstruction), the enzyme cytokinase is activated. It converts proenzymes into active forms directly in the organ tissue, bypassing the intestinal lumen.
Why is a tolerance test performed before administering proteolysis inhibitors?
These drugs are of protein nature (e.g., pantripin is isolated from bovine pancreas). They are foreign to the body and carry a high risk of allergic reactions.
How do proteolysis inhibitors affect blood coagulation?
Aprotinin-based drugs reduce the fibrinolytic activity of the blood by suppressing plasmin. This provides a pronounced hemostatic effect, which is why they are contraindicated in hypercoagulation.
What else to study on this topic
- The role of cytokinase in the pathological cascade of pancreatic enzyme activation.
- The mechanism of formation and action of free kinins in acute inflammation.
- The relationship between plasmin activity suppression and the hemostatic effect of aprotinin.
- Differential choice of diluent (glucose or sodium chloride) for intravenous infusions of protein drugs.
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