Problems of using decongestants in therapeutic and pediatric practice

Abstract

One of the current problems of the therapeutic and pediatric practice is an overuse of vasoconstrictors. Often after a treatment course by this group of drugs, patients cannot stop to use them, exceed the period of treatment and dosage prescribed by the doctor, that leads to the development of medical rhinitis.

Full Text

RATIONALE One of the current problems of the therapeutic and pediatric practice is an overuse of vasoconstrictors. Often after a treatment course by this group of drugs, patients cannot stop to use them, exceed the period of treatment and dosage prescribed by the doctor, that leads to the development of medical rhinitis. PURPOSE The objective is study of the mechanisms of action and occurrence of addiction to decongestants in order to develop effective methods of preventing medical rhinitis. METHODS Scientific literature analysis. RESULTS For a long time vasoconstrictors have been keeping leading positions as most frequently used drugs for the treatment of acute respiratory diseases associated with inflammation of the nasal mucosa and paranasal sinuses. They are preferred due to the quick effect and easiness of use. This work is dedicated to decongestants, the drugs which therapeutic effect is aimed at relief of the nasal congestion and upper respiratory tract infection. The mechanism of action of decongestants based on vasoconstriction of the nasal mucosa vessels, thus reducing swelling and hypersecretion of the mucous membrane. Breathing normalizes, blood oxygen saturation reaches normal values, the patient starts feeling better, as well as the drainage of the paranasal sinuses becomes easier. All this helps reduce the risk of complications development such as otitis media, eustachitis, sinusitis, etc. [1]. It is important to have nasal breathing for newborns and infants. Unless so the child is forced to interrupt feeding. This may affect the physical development of the child. Infants are especially at risk of complications from the auditory organs since the auditory tube is short and wide. There are two main classes of the drug that are identified being based on the application method: for topical and systematic action. They are both released in a form of topical action and in a form for systematic action. Decongestants are applied topically in case of rhinitis, including allergic ones, sinusitis, eustachiitis, and conjunctivitis, to stop nasal bleeding and for rhinoscopy preparation. The imidazoline (oxymetazoline, xylometazoline, tetryzoline) and benzene methanol (phenylephrine) derivatives remain the most commonly used at the moment. The mechanism of their action is mediated by the sympathomimetic effect in the form of activation of the postsynaptic α-adrenergic receptors of blood vessels of the nasal mucosa. Among the side effects of the decongestants (alpha-adrenergic agonists) they often distinguish the following: 1) The rebound effect, which appears in deterioration of the symptoms after the cancellation of drugs; 2) The appearance of discomfort, dryness and burning of the nasal mucosa; 3) Hyposecretion of mucus; 4) The appearance of systematic effect in case of prolonged contentious usage such as headache, dryness and irritation of the mucous membrane of the eye, psychomotor excitation, tremor of the limbs, tachycardia; 5) Reactive rhinitis; 6) The relative area of the nasal mucosa, the permeability of the blood-brain barrier in children is greater than in adults. There is a high probability of side effects of a systemic nature (tachycardia, hyperexcitability and vice versa bradycardia, lethargy). Therefore, it is necessary to strictly observe the dosing regimen [2]; 7) However, the most common complication appears to be the development of an addiction to the use of vasoconstrictor medication, especially of the topical action. The pathogenesis of decongestants addiction development: the maximum result is observed in about 40 minutes, and after 4-6 hours the effect is completely disappearing and substituted with the rebound effect. Thus, an optimal therapeutic effect requires frequent use of these drugs. Abuse of decongestants results in the development of tachyphylaxis, the rapidly diminishing response to successive doses of a drug. Smooth muscle cells of blood vessels of the nasal cavity loose sensitivity to endogenous norepinephrine. A patient is forced to extend the period of treatment for than 7 days and to increase the frequency of drug application. Attempt to stop the usage of decongestants results in uncontrolled vasodilation, mucosal oedema, hypersecretion of mucus. Symptoms reappear in greater severity compering to initial state resulting in drug-induced rhinitis accompanied by difficult clinical symptoms and the patient runs in a vicious circle; 8) Above described condition can develop for individuals with nasal hyperreactivity, even after a short course of treatment. The reason for it is an increased blood volume in the cavernous vascular network of the nasal shells and oedema of the mucous membrane. The first mechanism is normal for healthy people and reversible. Development of the second mechanism can occur in predisposed individuals with existing nasal hyperreactivity which leads to strong medically induced addiction [3]. Addiction is hard to cure. But in order to do so, it is recommended to either change used substance and alternate it with salt solutions rinsing procedure or better stop the usage of decongestant at all. To cure the addiction doctors often prescribe topical corticosteroids, antihistamines, physiotherapy and laser treatment. CONCLUSION It is important to remember that in the treatment of rhinitis, the etiological treatment comes first, and vasoconstrictive drugs are pathogenic with the temporarily relief symptoms, thus they are only an addition to the primary treatment. It is necessary to strictly observe the dosing regimen and the duration of use of anticonegastants.