Dorothy FarrarAntihistamines (histamine receptor blockers)
Antihistamines are naturally occurring or artificially produced active ingredients that can reduce or almost completely prevent the effect of histamine in the human body. This plays an important role in allergies, in which antihistamines are used pharmaceutically. But antihistamines are just as naturally occurring as histamine itself.
What are antihistamines?
Antihistamines are used against the pathological effects of histamine . Histamine is a natural substance that exists in every living thing. This is normal and healthy because it structures the tissues of humans, animals, plants and bacteria . This works in human and animal tissue at the hormonal level. As a neurotransmitter , histamine plays an important role. It regulates stomach acid and sleep patterns . In addition, histamine takes care of the defense against foreign substances that could possibly harm the body. In this way, allergiestriggered. Antihistamines, on the other hand, are usually sold over-the-counter or prescribed by a doctor, depending on the severity or complexity of the allergies and the required dosage of the antihistamines.
Effect and medical application
Antihistamines are mainly used to treat allergy symptoms. When allergens hit the mast cells, they release histamine to fight off the foreign substances. The messenger substance histamine only produces an allergic symptom when it docks with the corresponding receptor protein. When an antihistamine is taken, it acts on the receptor protein, thereby relieving the allergic symptoms. In the case of allergies, antihistamines are used primarily against rhinitis , itching or conjunctivitis .
They usually work within a very short time and, depending on the active ingredient, are used medically topically through nasal sprays , eye drops , ointments or systemically as tablets. In addition to allergies, antihistamines are also used to treat gastric mucosal inflammation. The modes of action of antihistamines thus cover a spectrum from antiallergic to anti-inflammatory . Some are also mast cell stabilizing, which from a therapeutic point of view is extremely useful for allergy sufferers in the long term. Other antihistamines calm and promote sleep and may also help with dizziness or vomiting.
shapes and groups
Appropriate antihistamines are used depending on which receptors are affected. The H2 receptors are found in the stomach, which is why H2 antihistamines are used in the case of excess gastric acid, and H1 antihistamines in the case of an allergy. H4 receptors are involved in the immune system and in inflammatory processes. Research into these receptors is still young, which is why there are not so many different forms of medication for these histamine receptors.
The antihistamines are differentiated according to generations. Those of the older generation cause central brain disturbances, such as dizziness and drowsiness, because they breach the blood-brain barrier . This is an undesirable effect that is no longer present with second-generation antihistamines. They no longer reach the brain, which means that the undesirable sedative effect is only found in first-generation antihistamines. Younger, well-known active ingredients such as cetirizine or fexofenadine are prescribed by doctors under the trade names Zyrtex® or Telfast®.
dosage
The antihistamines are always dosed as prescribed by the doctor or according to the package insert. A distinction must be made between external use of ointments, nasal sprays or eye drops and internal use of tablets or drops. Nasal sprays such as Livostin® with the active ingredient levocabastine are dosed twice a day with two sprays per nostril. In addition, the dosage of antihistamines differs according to age. Active substances of the second generation are mainly used against allergies and have a longer duration of action of 12 to 24 hours. Therefore, they are easy to dose and usually only have to be taken once a day in tablet form. Here, too, the medical prescription of the antihistamines is decisive.
Herbal, natural and pharmaceutical alternatives
When it comes to antihistamines, too, the first thing to remember is that a wholesome diet with lots of fresh vegetables is a healthy basis. On the one hand, proteins found in food have a direct influence on the receptor proteins. On the other hand, natural alternatives are supportive due to their histamine-lowering effect.
As a spice, turmeric has an antiallergic effect, as do wild thyme, wild oregano and basil . Quercetin, a natural plant pigment that is found in apple peel, currants , blueberries , red cabbage and purple onions, among other things, has anti-allergic and anti-inflammatory effects. Thus, natural and herbal alternatives can serve as a basis for human health in their function as antihistamines and anti-inflammatory drugs.
Interactions and side effects
Natural and herbal antihistamines, such as fresh turmeric roots, fresh herbs or quercetin in vegetables and fruits, usually have no interactions or side effects. Pharmaceutical antihistamines such as nasal sprays, on the other hand, can cause hypersensitivity reactions, nasal irritation, dizziness, a bitter taste in the mouth, or fatigue.
As an interaction, fatigue can occur due to the influence of alcoholic beverages or the use of other medications. This also applies to antihistamines in the form of eye drops or tablets. Possible interactions with other eye drops are unknown. As a precaution, the antihistamine eye drops should be used 15 minutes apart from other eye drops.
The use of antihistamine eye drops can also lead to side effects such as reddening of the eyes , dry eyes , sensitivity to light , blurred vision, tearing, a foreign body sensation, discoloration of the cornea or taste disorders. Taste disturbances are possible because the eye drops drain into the throat area after being dropped into the eye.
Rarely, skin rashes or headaches may occur. Allergic reactions can also occur. Possible side effects and interactions of the antihistamines must be clarified with the doctor in any case.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.