Preparations from an allergy
Treatment of all allergic diseases is almost the same and consists in the mandatory isolation of the patient from contact with the provoking substance-allergen;In the conduct of specific immunotherapy, which helps to teach the body not to manifest hyper-reaction to the incoming allergen;In non-specific therapy, which consists in taking anti-inflammatory non-steroid drugs, corticosteroids and antihistamines.
. Antihistamines against allergy.
. Antihistamines are drugs whose main effect is aimed at blocking H1-histamine receptors. Also, there are drugs that block H2-histamine receptors, which are often used as antiulcer drugs, becauseThey reduce secretion.
Thanks to numerous studies it was found that histamine, affecting the receptors of the skin, eyes and respiratory system, causes allergy symptoms that antihistamines stop or prevent. Antihistamines prevent the bronchospasm caused by histamine-like substances and histamine itself and have local anesthetic, sedative, antiserotonin, anticholinergic, antispastic, anti-edematous and antipruritic actions.
By the time of creation antihistamines are divided into preparations of I, II and III generations. First-generation drugs - sedatives, second-generation drugs - non-sedatives, third generation drugs - active metabolites without cardiotoxic and sedative effects.
. Anti-histamine preparations of the first generation.
. First-generation drugs are reversibly linked to H1-receptors, so they need to be administered frequently, in sufficientLarge dosages. The main pharmacological properties of these drugs: hypnotic, sedative, anticholinergic action and a decrease in muscle tone. Also, these drugs can potentiate the effects of alcohol. They have an anti-histamine effect for about five hours( Tavegil preparation - about eight hours).
Sedative action occurs due to the fact that practically all the preparations of the first generation are fat-soluble, easily penetrate the blood-brain barrier, linking with the H1-receptors of the brain. In the case of combination with psychotropic drugs and alcohol, the sedative effect is enhanced. In some cases, there may be a psychomotor agitation. It is because of the sedative effect of most first-generation drugs that it is forbidden to use when carrying out actions requiring increased attention. All without exception preparations of the first generation enhance the effect of alcohol, monoamine oxidase inhibitors, non-narcotic and narcotic analgesics, hypnotics and sedatives.
The anticholinergic effect of these drugs causes atropine-like reactions, manifested by visual impairment, tachycardia, constipation, urinary retention, dryness in the nasopharynx and mouth. In rhinitis, these properties can be useful, and in bronchial asthma, they can only increase airway obstruction, cause an exacerbation of prostate adenoma and glaucoma.
Due to holinoliticheskomu action, the drugs have anti-puffing and antiemetic effects, which significantly reduces the symptoms of Parkinsonism.
For most antihistamines, cocaine-like( local anesthetic) action is characteristic.
In the case of long-term use, antihistamine activity may be reduced, therefore it is recommended to change the drugs every two to three weeks. After taking medications, the therapeutic effect is observed almost immediately, however, its effect is quite short-lived.
Several antihistamine preparations of the first generation, because of their hypnotic and soothing effect, are part of the combined preparations used for motion sickness, migraine and cold.
The first generation of antihistamines have such a wide range of side effects that they are often rejected for allergic diseases, and in some European countries, their implementation is generally prohibited.
Below we will present the most frequently used antihistamine preparations of the first generation:
• Dimedrol .Reduces the severity of pseudoallergic and allergic reactions, has a high antihistaminic activity. Due to its anticholinergic effect, anti-emetic and antitussive effects, while often causing a delay in urination and dry mucous membranes. In addition, diphenhydramine has a strong hypnotic and sedative effect and is often used as a normal sleeping pill. In case of individual intolerance to lidocaine or / and novocaine, diphenhydramine is their alternative in terms of local anesthetic effect. In this case, this drug is characterized by unpredictability of CNS effects and a fairly wide range of side effects.
• Diazolin .In this preparation sedative effect is much weaker than the diphenhydramine, while it often causes excitation and CNS side effects such as mental and motor retardation reactions, drowsiness, dizziness, bladder, gastrointestinal irritation. Some researchers claim that diazoline exerts a toxic effect on nerve cells
• Suprastin .The most used sedative antihistamine preparation, which has moderate antispasmodic and peripheral anticholinergic action, as well as significant antihistaminic activity. Suprastin-proven most effective in treating diseases such as perennial and / or seasonal allergic rhinoconjunctivitis, atopic dermatitis, eczema, urticaria and angioedema. Due to the fact that this drug does not accumulate in the blood serum, it can be used for a long time without the threat of overdose. Therapeutic effect occurs quickly enough, but of short duration, so as to increase its length often shows a combined reception with its non-sedating H1-blockers
• Tavegil .By its action, a dimedrol-like highly effective antihistamine with high anticholinergic activity. Sometimes, as an additional remedy, it is injected with angioedema and anaphylactic shock. According to the indications it can be used to treat pseudoallergic and allergic reactions. However, sometimes there is an allergy to Tavegil itself
• Peritol .In addition to antihistamine, this drug has a considerable antiserotonin effect, significantly increases appetite and is often used for migraine
• Fenkarol. Despite the fact that this drug antihistamine activity is less than that of dimedrol, it has a lower severity of sedative properties. In addition to reducing histamine in tissues, Fenkarol blocks H1-receptors. This drug serves as a good substitute in case of getting used to other antihistamines
• Pipolphen .It is used to potentiate anesthesia and as an antiemetic. Has pronounced effects on the central nervous system
antihistamines II generation drugs
Antihistamines against allergies II generation, unlike its predecessors, does not possess anticholinergic and sedative effects do not affect the physical and mental activity, do not get behind the blood-brain barrier is not adsorbed with products inGIT, have a rapidly advancing therapeutic effect. However, despite their obvious advantage over drugs generation passed from allergies, generation II of cardiotoxic drugs have varying degrees of effect, so taking them require continuous ambulatory monitoring of cardiac activity. These drugs are banned for use by the elderly and patients with any disability in the work of the cardiovascular system.
The effect of these drugs lasts longer and comes faster. If you use drugs in the recommended therapeutic dosage, the sedative effect is minimal. Moderate drowsiness can be observed only in the highly sensitive people, however, this does not require drug withdrawal. With prolonged use, antihistamine activity does not decrease.
Side-effect cardiotoxic effect arises due to blocking the potassium channels of the cardiac muscle with the drug. The risk of cardiotoxic effect is significantly increased in the case of combinations of antihistamines with antidepressants( paroxetine, sertraline, fluoxetine), macrolides( clarithromycin, erythromycin) and antifungals( itraconazole, ketoconazole).
The most commonly used second generation antihistamines:
• Trexyl( Terfenadine) .This drug for allergies is the first drug of this generation. Despite the fact that it does not have a depressant effect on the part of the central nervous system, it has an increased ability to provoke the development of fatal arrhythmias and significant cardiotoxic action.
• Histalong( Astemizole) .The most long-acting( about 20 days) drug from this group. Histalong does not interact with alcohol, the sedative effect is almost completely absent. The most effective has proved itself in the treatment of chronic allergic diseases. When the acute process proceeds, its use is considered impractical. The main serious contraindication is the risk of developing( sometimes even fatal) cardiac arrhythmias
• Semprex( Acryvastin) .The therapeutic effect with the use of this drug is short-lived, but it is achieved very quickly. This drug with minimal anticholinergic and sedative effects with high antihistaminic activity
• Fenistil( Dimetenden) .By its composition it is the closest to the drugs from the allergy of the last generation, but it differs markedly from them by a much less pronounced sedation effect, longer duration of action and higher antiallergic activity. Practice is the release form in the form of a gel for external use
• Claritin( Loratadin) .The most purchased drug of the second generation. Due to greater binding strength to H1 receptors, antihistamine activity is higher in him than in Terfenadine and Astemizol. The drug does not potentiate the effect of alcohol, the sedative effect is absent, cardiotoxic effect does not possess, with other medicinal preparations practically does not interact. Claritin can be taken to children after the year and to drivers
Metabolites( 3rd Generation Antihistamines)
New drugs from the third generation allergy do not have cardiotoxic and sedative effects, and are therefore allowed for use by people employed in industries requiring increased attention.
The most used new drugs for allergy of the third generation:
• Telfast( Fexofenadine) .The drug does not interact with other drugs, has no effect on psychomotor activity, does not have a sedative effect. Among all antihistamines, Telfast can be considered the most effective and safest
• Cetrin, Zirtek .In the body, the drug is not practically metabolized, the rate of its withdrawal directly depends on the function of the kidneys. Well established itself with skin allergic manifestations, tk. Very easily penetrates into the skin. The therapeutic effect manifests itself within two hours from the moment of taking the drug and lasts for about a day. When taken in average therapeutic doses, cardiotoxic and sedative effects are absent. In case of impaired renal function, the drug should be taken with extreme caution
Nasal decongestants from the allergy
Most anti-allergic drugs contain such amphitamin-like substances as pseudoephedrine hydrochloride or components found in cold medicines used for colds. Such side effects as cardiovascular disorders, insomnia and nervousness usually arise when allergic reactions are treated with these drugs. In addition, decongestant nasal preparations allergic symptoms( sore throat, cough, sneezing, watery and itchy eyes, runny nose) are not removed, but they can cure only the stuffiness of the nose, which is by no means the main annoying allergic symptom.
Manufacturers recommended nasal decongestants without the effect of "drowsiness": Sudafed and Afrinol. However, for allergies, it is not recommended to use them.
