Decongestants are drugs that exert a decongestant effect and are used as supportive agents in the treatment of allergic diseases. They are not a uniform group of active substances. The individual substances act according to different mechanisms but with the same result of mucosal decongestion in each case.
What are decongestants?
Decongestants are drugs that exert a decongestant effect and are used as supportive agents in the treatment of allergic diseases. The term decongestants covers active substances whose only common feature is their decongestant effect. Chemically, these substances often have nothing to do with each other. Nor do the decongestants have a common mechanism of action. However, they are always used together with anti-allergics or other agents for the symptomatic treatment of swollen mucous membranes. While in these medications the main active ingredient causally combats the allergy, the decongestants only relieve the swelling and have a temporary effect. Decongestants are usually applied topically (topical), but can also be administered orally. Their main use is for allergic rhinitis (hay fever).
Medicinal use and effect
Decongestants can be divided into different drug classes depending on their mechanism of action. First of all, these are the sympathomimetics. These act directly or indirectly through the receptors of the sympathetic nervous system. The sympathetic nervous system is part of the autonomic nervous system and primarily controls the smooth muscles of the glands and blood vessels. It increases the tone of the heart and skeletal muscles, cardiac activity, blood pressure and metabolism. Furthermore, it dilates the bronchi and has a decongestant effect on the mucous membranes. Corticosteroids are another group of decongestants. The corticosteroids have an anti-allergic effect by dampening the immune system and thus have a decongestant effect on the mucous membranes. Other anti-allergic drugs that do not belong to the decongestants (e.g., cromoglicic acid) inhibit the release of inflammatory mediators, such as histamine, from the mast cells after long-term use, so that long-term use is necessary for treatment. Reproterol is always used in conjunction with cromoglicic acid to support rapid mucosal decongestion. Reproterol is a sympathomimetic and can be described as a decongestant. Other decongestants have homeopathic effects, such as Luffa operculata, an active ingredient from the dried pumpkin fruit. Essential oils also have a decongestant effect and are used as decongestants. They often have an anti-inflammatory effect. Furthermore, there are still special active ingredients that act as decongestants.
Herbal, natural, homeopathic, and pharmaceutical decongestants.
Various decongestants of the sympathomimetic drug group are very commonly used topically in nasal sprays to treat nasal mucosal swelling in allergic rhinitis. These include, for example, ephedrine, phenylephrine, tetryzoline, xylometazoline, naphazoline, tramazoline, or epinephrine. These agents are chemically synthesized and, in addition to their use as decongestants, are sometimes used in other fields. The other important group of decongestants are cordicosteroids. Here are such important representatives as beclometasone, prednisolone, dexamethasone, flunisolide, budesonide, betamethasone, tixocortol, fluticasone, mometasone or triamcinolone. This group of active ingredients also mainly contains representatives that are produced synthetically. The active ingredients of the cordicosteroid group are often applied orally for the systemic treatment of allergies. In addition, combinations of decongestants within a group of active ingredients are also used. Decongestants of plant origin are often essential oils. Chamomile and menthol should be mentioned as examples. Of plant origin is also the homeopathic active ingredient Luffa operculata, which comes from the dried pumpkin fruit. Some special representatives of the decongestants cannot be assigned to a specific group of active ingredients. They are individual active substances of different chemical composition and with different mechanism of action. These special substances include retinol, ipratropium bromide, hyaluronic acid, and hypromellose.
Risks and side effects
As diverse as the group of decongestants is, so are its side effects.It should be noted that every active ingredient can cause side effects. These can occur, but do not have to. In principle, it can be assumed that there is also a corresponding hypersensitivity reaction to each individual active ingredient, which can sometimes also manifest itself in an allergic shock. Furthermore, the active substances of the group of sympathomimetics cause side effects resulting from the increased activity of the sympathetic nervous system. These include increased blood pressure, increased cardiac activity, constipation, dry mouth, reduced secretion and much more. Cordicosteroids, in turn, have an immunosuppressive effect and, in extreme cases, can cause diabetes or osteoporosis. However, the application amounts are usually so small that side effects are usually negligible.
