For the treatment of pulmonary diseases caused by spasm of the respiratory tract, bronchodilators from the methylxanthine group are used. Their main representative is the theophylline substance.
Drugs based on it relieve asthma attacks in patients with bronchial asthma, obstructive bronchitis and nocturnal apnea.
Drug description
The drug “Neofilin” (tablets) describes the instructions for use as a medicine produced by the Ukrainian pharmaceutical company “Darnitsa” in two dosages: 100 and 300 mg each. The medicine has a prolonged effect.
Action on the body
The active component of the drug (theophylline) has a bronchodilator effect on the body, during which adenosine receptors are blocked, phosphodiesterase is inhibited, the content of intracellular cyclic adenosine monophosphate increases, and the concentration of calcium ions decreases. There is a relaxation of smooth muscles in the bronchi, digestive tract, bile ducts, uterus, coronary, pulmonary, cerebral vessels, expansion of the coronary arteries, and a decrease in peripheral vascular resistance.
Under the influence of the drug, there is an increase in the tone of the respiratory muscles, which include intercostal muscles and the diaphragm. In addition, the resistance of the blood vessels of the lungs decreases, oxygenation of the bloodstream improves, the respiratory center in the medulla oblongata activates, its susceptibility to carbon dioxide increases, and alveolar ventilation improves.
As a result, the severity decreases and the frequency of respiratory arrest stops. Theophylline in the Neofilin preparation (tablets) describes the instructions for use as a means to eliminate angiospasm, increase collateral blood flow and oxygen saturation of the blood, reduce perifocal and general cerebral edema, decrease cerebrospinal fluid and intracranial pressure.
The medication is intended to improve the rheological characteristics of blood, prevent blood clots, reduce clumping of platelet cells, and normalize microcirculation. Theophylline exhibits an anti-allergic effect in which mast cells are degranulated and the concentration of allergic mediators, such as histamine, serotonin, leukotriene, is reduced.
Due to increased renal blood flow, a diuretic effect is observed in which water, chloride ions and sodium are excreted.
What heals the drug
The Neofilin 100 medicine (tablets) recommends the use of bronchial asthma, asthma, chronic obstructive bronchitis , bronchial obstruction of the lungs, pulmonary hypertension, nighttime respiratory arrest.
Such recommendations apply to a larger dosage of the drug - 300 mg each.
How to use
The drug "Neofilin" (tablets), the instructions for use are advised to be taken in a dose that is set for each disease separately and depends on the speed of metabolic processes, age characteristics and weight category of the patient.
The drug is drunk 1 time per day during breakfast or dinner. The medication "Neofilin" (tablets) instructs you to take it in strict mode. You can’t drink the medicine with food during one day, and the next day after eating.
Dosage calculation for normal renal clearance
For the initial and further selection of the amount of the drug, it is necessary to determine the intensity values of the purification of blood plasma from all kinds of substances by the kidneys.
The drug Neofilin (tablets), instructions for use for children from 12 to 15 years old with a body weight of less than 45 kg are recommended for use in the first three days of therapy in a daily dose of 12 to 14 μg per 1 kg of weight. But you can not take more than 300 mg of the drug.
After three days of such treatment, subject to normal tolerance, the daily dose rises to 16 mcg per 1 kg of weight. But it should not exceed 400 mg per day.
After the next three days, subject to normal tolerance, the dosage rises to 20 mcg per 1 kg of weight. But now it should not be more than 600 mg.
The drug "Neofilin" (tablets), instructions for use for children from 16 years of age and for adults up to 60 years of age with a body weight of more than 45 kg in the first three days of treatment, it is recommended to use orally in an amount of 300 to 400 mg per day.
Three days later, subject to normal tolerance, the dose rises to 400-600 mg.
Three days later, under the same circumstances, the daily dosage may exceed 600 mg, but it is necessary to organize control of theophylline concentration in the patient’s blood.
Dosage calculation for impaired renal clearance and for the elderly
How to take the drug Neofilin (tablets) to other categories of patients? The instruction for children recommends taking it in a dose that should not be higher than 16 mg per 1 kg of body weight per day, but not more than 400 mg in total. These recommendations apply to adolescents from 12 to 15 years old with impaired renal clearance or in the absence of the ability to monitor the plasma concentration of theophylline.
For the drug "Neofilin 300" (tablets), the instructions for use include the following data. They relate specifically to the use of the medication by adolescents after 16 years of age and patients in old age with impaired renal clearance, as well as people who cannot measure theophylline plasma concentration. Typically, for such categories of patients, the amount of active substance of this drug should not exceed 400 mg.
Calculation of dosage by the plasma concentration of theophylline
Depending on the content of the active component in the plasma, dose adjustment of the Neofilin 100 preparation (tablets) is carried out. The instruction prescribes such actions to be performed when taking a larger dosage of the medication. It is necessary to reduce the level of the active substance and control its amount in the serum in case of adverse reactions, a physiological disturbance that inhibits the elimination of the drug.
If the peak concentration of theophylline in the blood is less than 9.9 μg per 1 ml, then the absence of the effect of the drug with normal tolerance requires a 25 percent increase in dosage. Three days later, for the next change in the amount of the drug, the plasma concentration of theophylline is checked.
If the effect of the treatment has come and tolerance is good, further therapy with the same dosage is possible only after determining the plasma concentration of the active component. At the same time, its indicator should be in the range from 10 to 14.9 μg per 1 ml. If there is no effect, but tolerance is good, add other drugs.
When to reduce the dose
When the plasma concentration of theophylline is in the range of 15 to 19.9 μg per ml, a dosage reduction of 10% is required.
With a substance index of 20 to 24.9 μg per ml, it is necessary to reduce the amount of the drug by 25%, even if no adverse reactions have manifested. Three days after the dose reduction, the theophylline plasma indicator is monitored to establish the possibility of further use of the drug.
If the level of the active substance is from 25 to 30 μg per 1 ml, the subsequent dosage is skipped, and in the future it is necessary to reduce the amount of medication by 25%.
Three days after the dose is reduced, the plasma index of theophylline is monitored to determine the feasibility of further use of the drug. If symptoms of unwanted effects are possible, take appropriate measures.
When theophylline concentration in the blood is more than 30 mcg per 1 ml, an overdose condition may occur. For further use, the dose is reduced by half. After three days, a repeated measurement of the amount of the drug in the plasma is carried out and the dosage is adjusted.
Application Feature
When smokers take Neofilin 100 tablets, the instructions for use warns of a possible decrease in the effect of treatment.
For people with severe diseases of the heart, blood vessels, liver, infection of a viral nature, in old age, the dosage of the drug is selected individually, and the medicine is taken in these cases with extreme caution.
Excess drug
In adult patients, an overdose of the Neofilin 300 medication (tablets) is characterized by seizures, fever, impaired heart function, including tachycardia, ventricular arrhythmia, hypotension.
Symptoms characteristic of childhood include increased irritability, mental disorders, high fever, nausea, convulsive state, tachycardia, hypotension, and respiratory arrest.
To cure, first of all, stop taking the tablets, then rinse the stomach, irrigate the intestines with a combination of salts with polyethylene glycol, take activated charcoal. It is recommended to stimulate the removal of theophylline from the blood with the help of forced diuresis, hemosorption, plasmosorption, hemodialysis, peritoneal dialysis.
In case of nausea and vomiting, the patient is prescribed symptomatic drugs, for example, taking Ondansetron or Metoclopramide. To eliminate seizures, Diazepam can be taken.
Who should not be taken
For the Neofilin 100 preparation (tablets), the instructions include a list of contraindications in which medication is not possible. They include hypersensitivity to all components of the drug, to xanthine-type medicines, which include caffeine, theobromine, pentoxifylline.
It is impossible to take in acute myocardial muscle infarction, tachyarrhythmia, obstructive hypertrophic cardiomyopathy, severe arterial hypertension, epilepsy, hyperthyroidism, peptic ulcer in the stomach or duodenum, severe liver dysfunction, porphyrin disease.
Contraindicated in children under 12 years of age.
Adverse reactions
A number of side effects can develop from taking the drug "Neofilin" (tablets). Instructions for use inform patients about the possible manifestation of disorders in the gastrointestinal tract. They are characterized by pain in the abdomen, nausea, vomiting reflex, gastroesophageal reflux, heartburn, exacerbation of an ulcer, diarrhea, and decreased appetite.
Undesirable reactions are manifested in the cardiovascular system in the form of palpitations, tachycardia, cardiac arrhythmias, decreased blood pressure, cardialgia, angina pectoris.
Theophylline can affect the central nervous system. It can be expressed by dizziness, headache, restless or agitated state, sleep disturbance, tremor, delirium, convulsions and convulsions.
When taking the drug, allergic reactions are possible with the occurrence of skin rash, erythema, exfoliative dermatitis, urticaria, fever.
Other undesirable consequences of treatment include hair loss on the head, chest pain, superficial rapid breathing, hot flashes, the release of albumin protein in the urine, the presence of blood in the urine, increased diuresis, increased sweating and skin temperature.
Theophylline affects the performance of laboratory tests. During treatment with Neofilin, the content of potassium ions in the blood serum can change in the direction of reduction with the development of hypokalemia. At the same time, the level of creatinine, calcium ions , oxalates, which are salts of uric acid, and sugars increases, which leads to hypercalcemia, hyperuricemia and hyperglycemia.
After reducing the dosage of the drug, the degree of side effects decreases.
Pregnancy and lactation
The active component of the tablets is able to penetrate the placental barrier and pass into breast milk.
For pregnant women, admission is possible only when the effect of treating the mother is higher than the risk for the unborn child. In the case of such therapy, a frequent determination of the plasma concentration of theophylline and an appropriate dosage adjustment of the agent are necessary. Admission of the drug in the last months of pregnancy is undesirable due to the suppression of uterine muscle contraction.
Women who breastfeed and are treated with theophylline should observe the appearance of hypersensitivity in the baby. Perhaps the development of arousal or sleep problems, which requires discontinuation of the drug.