Pharmacological class and pulmonology use
The drug Trypsinum crystallisatum (Trypsin) is classified as an agent affecting respiratory system functions. Within this classification, it belongs to enzymatic mucolytics (a group of proteolytic enzymes that also includes chymotrypsin).
As a mucolytic, the drug breaks down viscous airway secretions, facilitating their clearance. However, in modern clinical practice, enzymatic mucolytics (trypsin, ribonuclease, deoxyribonuclease) are used significantly less frequently. They have been largely replaced by synthetic agents (acetylcysteine, carbocisteine, ambroxol, bromhexine).
Endogenous trypsin and replacement therapy
In addition to its use as a mucolytic, trypsin is a critical endogenous enzyme. Within combined, multi-enzyme animal-derived preparations (e.g., Pancreatin, extracted from bovine pancreas, and its analogs Mezym, Triferment), proteases play a key role in digestion.
Although pancreatin dosing is based on lipase activity (daily dose of 5–10 g), the proteolytic enzymes it contains are essential for enzyme replacement therapy in chronic pancreatitis, hepatopancreatic disorders, and hypoacidic or anacidic gastritis. Such medications are administered strictly before meals.
Role of trypsin in the pathogenesis of pancreatitis
Special attention in pharmacology should be paid to the role of trypsin in tissue destruction. Normally, the pancreas secretes an inactive proenzyme: trypsinogen.
In acute pancreatitis, acute exacerbations of chronic pancreatitis, trauma, pancreatic cancer, or duodenal wall edema (e.g., after alcohol intake), pancreatic outflow is obstructed. Under these conditions, the enzyme cytokinase is activated. It triggers a pathological cascade: trypsinogen is converted into active trypsin directly within the pancreatic parenchyma rather than in the intestinal lumen.
This phenomenon is known as “self-digestion” or autolysis. Active trypsin destroys glandular tissue and, entering the systemic circulation, leads to severe toxemia.
Pharmacological regulation: inhibitors and blockers
To manage autolysis and toxemia, drugs that suppress trypsin activity are utilized:
- Proteolysis inhibitors (antienzymes): Pantripin (a polypeptide derived from bovine pancreas) and Aprotinin (Gordox, Trasylol). They specifically inactivate circulating trypsin in the bloodstream and block free kinins (mediators of inflammation and pain). They are administered as high-dose IV infusions (in 5% glucose or 0.9% NaCl). Caution is required due to the high risk of allergic reactions to foreign proteins.
- M-cholinergic antagonists: Agents of this class (e.g., atropine) decrease pancreatic secretion of trypsinogen. This prevents its premature activation and protects the parenchyma from autolysis.
Dosage form and rules of administration
When trypsin is prescribed as a mucolytic agent, the inhalation route is used.
- Dosage form: Powder in ampoules or vials containing 0.005 g and 0.01 g.
- Reconstitution guidelines: Before inhalation, dissolve 0.005 g or 0.01 g of powder in 2–3 mL of 0.9% sodium chloride (NaCl) solution.
Briefly: answers to topical questions
What is the biochemical mechanism of the mucolytic action of trypsin?
The mucolytic action of trypsin relies on liquefying thick, viscous secretions in inflammatory airway diseases via proteolysis. At the biochemical level, trypsin acts as an endopeptidase: it predominantly cleaves internal peptide bonds within protein molecules.
In which surgical conditions is trypsin applied topically?
Trypsin is used topically in the following surgical conditions:
- Purulent wounds — for wound debridement and digestion of necrotic cell proteins.
- Postoperative wounds — as part of intensive postoperative wound care to target local proteolytic activity and establish optimal conditions for healing.
- Trophic ulcers — topically as a solution or powder.
The goal of proteolytic enzyme therapy is to cleanse the affected site of necrotic tissue, fibrin, and pus.
Trypsin clears the bronchial tree, but in the pancreas, it sets autolysis free.
Class and exam questions
What class of mucolytics does trypsin belong to?
To enzymatic mucolytics (proteolytic enzymes). In modern clinical practice, they are used far less commonly than synthetic alternatives.
What is the role of trypsin in the pathogenesis of acute pancreatitis?
When secretion outflow is obstructed, cytokinase converts trypsinogen into active trypsin directly within the pancreatic tissue. This causes autolysis (self-digestion) of the organ and severe toxemia.
Which drugs inactivate circulating trypsin in the bloodstream?
Proteolysis inhibitors (antienzymes), such as Pantripin and Aprotinin. They bind circulating trypsin and halt destructive tissue damage.
How should trypsin be reconstituted for inhalation?
The contents of the ampoule (0.005 g or 0.01 g of powder) must be reconstituted in 2–3 mL of 0.9% sodium chloride solution.
What else to study on this topic
- Synthetic mucolytics (acetylcysteine, ambroxol) and their advantages over enzymatic agents
- Proteolysis inhibitors (Aprotinin, Pantripin): mechanism of action and clinical indications
- Pancreatic enzyme replacement therapy (Pancreatin, Mezym)
- Pathogenesis of acute pancreatitis and the role of cytokinase
- Use of M-cholinergic antagonists (atropine) to suppress trypsinogen secretion
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