Fibrinolysin is an enzyme derived from plasma of
bovine
Bovines (subfamily Bovinae) comprise a diverse group of 10 genera of medium to large-sized ungulates, including cattle, bison, African buffalo, water buffalos, and the four-horned and spiral-horned antelopes. The evolutionary relationship betwee ...
origin (
plasmin
Plasmin is an important enzyme () present in blood that degrades many blood plasma proteins, including fibrin clots. The degradation of fibrin is termed fibrinolysis. In humans, the plasmin protein (in the zymogen form of plasminogen) is encoded ...
) or extracted from cultures of certain
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
. It is used locally only and exclusively together with the enzyme desoxyribonuclease (extracted from bovine pancreas). Fibrinolysin and desoxyribonuclease both act as lytic enzymes. The combination is available as ointment containing 1 BU (
Biological Unit) fibrinolysin and 666 BUs desoxyribonuclease per gram.
Fibrinolysin attacks and inactivates
fibrin
Fibrin (also called Factor Ia) is a fibrous, non-globular protein involved in the clotting of blood. It is formed by the action of the protease thrombin on fibrinogen, which causes it to polymerize. The polymerized fibrin, together with platele ...
molecules occurring in undesirable
exudate
An exudate is a fluid emitted by an organism through pores or a wound, a process known as exuding or exudation.
''Exudate'' is derived from ''exude'' 'to ooze' from Latin ''exsūdāre'' 'to (ooze out) sweat' (''ex-'' 'out' and ''sūdāre'' 'to ...
s on the surface of the human body and on human
mucosa
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...
, e.g., in superficial
wounds
A wound is a rapid onset of injury that involves lacerated or punctured skin (an ''open'' wound), or a contusion (a ''closed'' wound) from blunt force trauma or compression. In pathology, a ''wound'' is an acute injury that damages the epider ...
and
burns Burns may refer to:
* Burn, an injury (plural)
People:
* Burns (surname), includes list of people and characters
Business:
* Burns London, a British guitar maker
Places:
;In the United States
* Burns, Colorado, unincorporated community in Eagle ...
, while desoxyribonuclease targets and destroys (human)
DNA. The combination of the two enzymes has a synergistic effect on necrotic but not on living
tissue. According to the manufacturer the ointment provides enhanced wound cleaning and accelerates the healing process.
Both enzymes are marginally resorbed into systemic circulation because of their very high molecular weight and their macromolecular structure.
The activity of both enzymes is almost completely exhausted after 24 hours. Usually, it is necessary to repeat the application (and renew the dressing) every 6 to 8 hours until healing becomes complete.
The ointment is marketed by
Pfizer
Pfizer Inc. ( ) is an American multinational pharmaceutical and biotechnology corporation headquartered on 42nd Street in Manhattan, New York City. The company was established in 1849 in New York by two German entrepreneurs, Charles Pfizer ...
under the brand name Fibrolan in a variety of countries (e.g. Switzerland). It is currently not approved in the USA.
Where approved, Fibrolan has been licensed on the basis of claimed good therapeutical experience, but adequate and well controlled studies are still lacking.
In the past, combinations with the antibiotic
chloramphenicol
Chloramphenicol is an antibiotic useful for the treatment of a number of bacterial infections. This includes use as an eye ointment to treat conjunctivitis. By mouth or by injection into a vein, it is used to treat meningitis, plague, cholera, a ...
were available, but because chloramphenicol in any form of application has led to
aplastic anemia
Aplastic anemia is a cancer in which the body fails to make blood cells in sufficient numbers. Blood cells are produced in the bone marrow by stem cells that reside there. Aplastic anemia causes a deficiency of all blood cell types: red blood ...
and death, these were banned. Additionally, combinations with the antifibrinolytic agent
tranexamic acid
Tranexamic acid (TXA) is a medication used to treat or prevent excessive blood loss from major trauma, postpartum bleeding, surgery, tooth removal, nosebleeds, and heavy menstruation. It is also used for hereditary angioedema. It is taken eith ...
have been withdrawn from pharmaceutic markets.
Indications
Enzymatic wound cleaning to assist healing of minor burns, superficial wounds,
ulcus cruris
Venous ulcer is defined by the American Venous Forum as "a full-thickness defect of skin, most frequently in the ankle region, that fails to heal spontaneously and is sustained by chronic venous disease, based on venous duplex ultrasound testing." ...
, and superficial
hematoma
A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillary, capillaries. A he ...
.
Contraindications and Precautions
The ointment should not be used in patients with a known
hypersensitivity
Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. They are usually referred to as an over-reaction of the immune s ...
to any ingredient. It should be used with caution in patients with hypersensitivity to bovine proteins in general and in pregnant women (category C), because no human data is available.
Side-Effects
Infrequently, local reactions such as increased pain or a stitching/burning sensation are noticed. No systemic
anticoagulant
Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where the ...
activity has been seen due to the exclusively local character of treatment.
Interactions
Not known.
See also
*
Staphylokinase (staphylococcal fibrinolysin)
External links
* Swiss scientific product information
*
{{Portal bar, Biology, border=no
EC 3.4.21
Hydrolases
Antithrombotic enzymes