Synonyms in a broader sense
Definition
Fenistil® is a non-prescription drug from the pharmaceutical company Novartis, which is available in many different forms and sometimes with different active ingredients. Common to all preparations is that they are mainly used to treat diseases or inflammation of the skin. Most of the products that this text mainly deals with are used for the (purely symptomatic) treatment of allergic diseases such as hay fever or animal hair or food allergies. The active ingredient of this product group, which also includes the Fenistil® gel, probably best known under the name Fenistil®, is called Dimetinden and is a drug from the group of H1 antihistamines.
Chemistry
Fenistil® gel is used when the skin is itchy and irritated or hurts, which can have various causes. These include allergic reactions caused by hay fever, food and animal hair allergies, certain skin diseases such as hives or neurodermatitis, insect bites or sunburn. Allergic reactions are caused when the body classifies a foreign body that is actually harmless, such as animal hair or flower pollen, as dangerous and the immune system consequently displays a hypersensitivity reaction.
In order to combat the apparently harmful substance, the organism reacts by producing a large number of messenger substances which are intended to provide protection. These include the tissue hormone histamine, which leads to an inflammatory reaction. As a result, histamine is one of the main triggers of the complaints that arise in the case of an allergy.
These include the dilation of small blood vessels, which is the cause of redness of the skin, local swelling, itching and pain. In addition, histamine makes the bronchial tubes tight to prevent further infiltration by the supposed enemy, which can cause breathing difficulties. Fenistil® (or the active ingredient Dimetinden) develops its effect at the binding sites for histamine.
It is known as an antihistamine of the H1 receptor antagonist type. This means that this substance blocks the H1 receptors to which histamine normally docks in order to exert its effect. So the body continues to release histamine as usual, but now that the binding sites for it are occupied, the body can no longer react as usual.
The inflammatory reaction is therefore attenuated or fails to occur (Fenistil®). The fact that this mechanism takes place not only in body tissue but also in the brain, where it inhibits the action of messenger substances similar to histamine, explains some of the side effects such as tiredness or dry mouth. The lack of response of the H1 receptors to histamine provides relief from most symptoms caused by allergies (redness, swelling, sneezing, nasal congestion, shortness of breath, swollen nasal mucous membranes, watery eyes) and also from itching due to chickenpox, hives (urticaria), neurodermatitis or insect bites (Fenistil®).
