Properties
What is it?
DIMEDROL-DARNYTSIA Composition: Active substance: diphenhydramine; 1 tablet contains 50 mg of diphenhydramine hydrochloride; Excipients: potato starch, lactose monohydrate, stearic acid. Dosage form. Tablets. Main physicochemical characteristics: White, flat-cylindrical tablets with a bevel and a dividing line. Pharmacotherapeutic group. Antihistamines for systemic use. Aminoalkyl ethers. Diphenhydramine. ATC code R06A A02. Pharmacological properties. Pharmacodynamics. Antihistamine. Blocks H1-histamine receptors, eliminating histamine effects: reduces or prevents spasms of smooth muscles of blood vessels, intestines, bronchi and bronchioles, increased capillary permeability, tissue edema, itching, and hyperemia. Dimedrol's antihistamine effect is more pronounced on local vascular reactions in inflammation and allergy than on systemic ones (lowering blood pressure). It has a local anesthetic effect (causes a short-term numbness sensation of the oral mucosa when taken orally), and has antispasmodic, ganglioblocking, and central anticholinergic activity. It has a sedative, hypnotic (more pronounced with repeated doses), and moderately pronounced antiemetic effect. The effect on the central nervous system is due to the blockade of H3-histamine receptors in the brain and the suppression of central cholinergic structures. It is more effective in bronchospasm caused by histamine liberators (tubocurarine, morphine, sombrevin) and less active in allergic bronchospasm. Pharmacokinetics. When taken orally, it is rapidly and well absorbed from the gastrointestinal tract. Binding to blood plasma proteins is 98-99%. Maximum concentration in blood plasma is reached 1-4 hours after oral administration. Most of the administered dose is mainly metabolized in the liver to form diphenylmethoxyacetic acid, a small part is excreted unchanged by the kidneys. It is well distributed in the body, crosses the blood-brain barrier, and passes into breast milk, which can cause a sedative effect in infants during lactation. The half-life is 2-8 hours. It is excreted by the kidneys mainly unchanged within 24-48 hours. The effect of the drug develops 15-30 minutes after intravenous administration, with the maximum effect observed 1-3 hours later. Duration of action is 4 to 6 hours. See blog: Dimedrol - a medication that relieves allergic and neurological symptoms. Clinical features. Indications. For the treatment of allergic reactions: urticaria, hay fever (pollinosis), angioneurotic edema, serum sickness, contact dermatitis, erythema multiforme exudativum, eczema, pruritus, hemorrhagic vasculitis (capillarotoxicosis), vasomotor rhinitis, respiratory allergosis, acute iridocyclitis. Allergic diseases of the eyes (conjunctivitis). For the prevention and treatment of allergic complications caused by the use of drugs (antibiotics, enzymes), to weaken side effects that develop during blood or blood substitute transfusions. Chorea, sea and air sickness, Meniere's disease. As a sedative and hypnotic for neurosis, neurasthenia, insomnia. Contraindications. Hypersensitivity to the components of the drug or other antihistamines; bronchial asthma attack, pheochromocytoma, epilepsy, prolonged QT interval or prolonged use of drugs that can cause QT interval prolongation and/or torsade de pointes. Porphyria. Angle-closure glaucoma, prostatic hyperplasia, stenosing peptic ulcer of the stomach and duodenum, pyloroduodenal obstruction, bladder neck stenosis, bradycardia, cardiac arrhythmias, sudden cardiac death in the family history, significant electrolyte imbalance (hypokalemia, hypomagnesemia). Interactions with other drugs and other types of interactions. Dimedrol enhances the effects of ethanol and central nervous system depressants: neuroleptics, tranquilizers, hypnotics, analgesics, narcotic drugs. Monoamine oxidase (MAO) inhibitors enhance the anticholinergic activity of dimedrol. Concomitant use of MAO inhibitors and dimedrol can lead to increased blood pressure, as well as affect the central nervous system and respiratory system. The drug should be used with caution during MAO therapy or within 2 weeks of stopping MAO therapy. Avoid combination with drugs that prolong the QT interval on electrocardiogram (ECG), such as class Ia and III antiarrhythmics. Since diphenhydramine has some antimuscarinic activity, the effects of some anticholinergic drugs (e.g., atropine, tricyclic antidepressants) may be enhanced, so consult a doctor before using diphenhydramine with such drugs. Antagonistic interaction is observed when co-administered with psychostimulants. It reduces the effectiveness of apomorphine as an antiemetic in the treatment of poisoning. Enhances the anticholinergic effects of drugs with m-cholinoblocking activity. It cannot be used concurrently with drugs containing dimedrol, especially for topical use. The risk of seizures is increased when combined with analeptics. The use of dimedrol with tricyclic antidepressants can enhance its m-cholinoblocking effect, which can lead to increased intraocular pressure in glaucoma. The use of dimedrol with hypotensive drugs can increase the feeling of fatigue. Dimedrol is an inhibitor of the cytochrome P450 CYP2D6 isoenzyme. Thus, interactions with drugs whose metabolism is primarily mediated by CYP2D6, such as metoprolol and venlafaxine, are possible. Dimedrol should not be taken by patients taking any of the aforementioned drugs. Special precautions for use. Dimedrol should be prescribed with caution in patients with myasthenia gravis or seizures. It should be used with caution in patients with hyperthyroidism, chronic obstructive pulmonary disease, elevated intraocular pressure, cardiovascular diseases, as well as in the elderly due to the high probability of developing dizziness, sedation, and arterial hypotension. The drug can cause dry eyes and discomfort when wearing contact lenses. The use of dimedrol is associated with QT interval prolongation on the electrocardiogram. Post-marketing surveillance has reported cases of QT interval prolongation and torsade de pointes associated with overdose. If the patient develops signs or symptoms that may be related to cardiac arrhythmia, treatment should be discontinued and immediate medical attention sought. Patients should be advised to report any cardiac symptoms immediately. Dimedrol should be used for the shortest possible duration. With frequent use, tolerance and/or dependence may develop. Do not take the drug continuously for more than 7 days without consulting a doctor. If insomnia persists, consult a doctor, as insomnia may be a symptom of a serious underlying condition. There have been reports of misuse and dependence with dimedrol in adolescents or young adults for recreational purposes, as well as in patients with mental disorders and/or a history of substance abuse. The development of signs or symptoms of abuse should be monitored. Avoid the use of other antihistamines, including topical antihistamines and cough and cold remedies. Use with caution in patients with a recent history of respiratory diseases (including bronchial asthma, bronchitis), arterial hypotension. The drug can worsen the course of obstructive pulmonary diseases, severe cardiovascular diseases, ileus, and the condition in biliary tract obstruction. Dimedrol can cause slowing down, as well as cause agitation and hallucinations, seizures, especially in overdose. It should be prescribed with caution in patients with impaired liver and kidney function. In patients with moderate to severe liver or kidney failure, dose reduction may be necessary. Alcohol consumption is contraindicated during treatment with the drug, and UV radiation should be avoided. The use of dimedrol as an antiemetic can complicate the diagnosis of appendicitis and the recognition of symptoms of overdose of other drugs. Patients with rare hereditary problems of galactose intolerance, lactase deficiency, or glucose-galactose malabsorption should not take dimedrol. Use during pregnancy and lactation. Dimedrol is contraindicated during pregnancy as there is no adequate data on its safety and efficacy. If the drug needs to be used, breastfeeding should be discontinued. The use of dimedrol during lactation can cause paradoxical stimulation of the central nervous system in infants who are breastfed. Ability to influence the speed of reaction when driving vehicles or operating other machinery. During treatment, refrain from potentially hazardous activities that require high concentration and rapid psychomotor reactions (driving vehicles, operating machinery). Method of administration and dosage. For adult patients, 1/2-1 tablet (25-50 mg of diphenhydramine hydrochloride) is prescribed 1-3 times a day. For the prevention of motion sickness, take 1/2-1 tablet 30-60 minutes before travel; as a sedative and hypnotic - 1 tablet before bedtime. The maximum single dose for adults is 2 tablets (100 mg of diphenhydramine hydrochloride), the maximum daily dose is 5 tablets (250 mg of diphenhydramine hydrochloride). For children aged 6-12 years, 1/2 tablet (25 mg of diphenhydramine hydrochloride) is prescribed per dose. The duration of the course of therapy is determined by the doctor individually depending on the nature of the disease. Children. The drug is used in children from 6 years of age. Overdose. Symptoms: dry mouth, difficulty breathing, mydriasis, facial flushing, central nervous system depression or excitation, tachycardia, arrhythmia, depression of cardiovascular and respiratory function, depression, hyperkinesia, confusion, delirium, fever, tremor, dystonic reactions and ECG changes; in children - seizures. High doses of dimedrol can cause rhabdomyolysis, delirium, toxic psychosis, coma, and cardiovascular collapse. Treatment: induction of vomiting, gastric lavage, administration of activated charcoal; symptomatic and supportive therapy with control of respiration and blood pressure. Intravenous infusion of plasma substitutes, oxygen therapy. Epinephrine and analeptics should not be used. In case of dimedrol overdose, physostigmine 0.06 mg/kg body weight can be administered intravenously several times as an antidote if anticholinergic symptoms increase. In case of physostigmine overdose, atropine administration is required. Treatment of seizures and pronounced central nervous system stimulation should be done with parenteral diazepam. Side effects. Side effects are given by system and organ and frequency: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1000 to <1/100), rare (≥1/10000 to <1/1000), very rare (<1/10000), frequency unknown (cannot be estimated from available data). From the organs of vision: frequency unknown - dry eyes, mydriasis, diplopia, visual impairment, very rare - increased intraocular pressure. From the organs of hearing and vestibular apparatus: frequency unknown - acute labyrinthitis, tinnitus, impaired coordination of movements. From the respiratory system, chest cavity and mediastinum: frequency unknown - dryness of the mucous membranes of the nose and throat, nasal congestion, thickening of bronchial secretions, feeling of tightness in the chest, difficulty breathing, shortness of breath. From the gastrointestinal tract: common - dry mouth, frequency unknown - numbness of the oral mucosa, anorexia, vomiting, epigastric pain, nausea, diarrhea, constipation. From the kidneys and urinary tract: frequency unknown - frequent and/or difficult urination, urinary retention. From the nervous system: common - sedative effect, weakness, drowsiness, decreased attention, decreased speed of psychomotor reactions, dizziness, increased fatigue; frequency unknown - anxiety, depression, increased excitability (especially in children), insomnia, nervousness, irritability, euphoria, confusion, tremor, neuritis, paresthesia, dyskinesias, headache; very rare - seizures. In patients with local brain lesions or epilepsy, seizure discharges on electroencephalography (EEG) are activated (even with low doses of dimedrol), the drug can provoke an epileptic seizure. Elderly people are prone to confusion and paradoxical excitation (e.g., increased energy, anxiety, nervousness). From the cardiovascular system: frequency unknown - arterial hypotension, palpitations, tachycardia, arrhythmia, extrasystole, cyanosis of skin and mucous membranes. From the blood and lymphatic system: rare - thrombocytopenia, frequency unknown - agranulocytosis, hemolytic anemia, hemolytic jaundice. From the immune system: frequency unknown - hypersensitivity reactions, including anaphylactic shock and angioneurotic edema. From the skin and subcutaneous tissue: frequency unknown - hyperemia, rash, itching, urticaria, very rare - contact dermatitis. From the musculoskeletal system and connective tissue: frequency unknown - muscle twitching. From the reproductive system and mammary glands: frequency unknown - increased menstrual frequency, early menstruation. General disorders: frequency unknown - sweating, tremor, photosensitization, fever, hyperthermia syndrome. Reporting of suspected adverse reactions. Reporting of suspected adverse reactions after the drug has been registered is an important procedure. It allows for continued monitoring of the benefit/risk balance of the drug. Healthcare professionals should be notified of any suspected adverse reactions through the national reporting system. Shelf life. 4 years. Storage conditions. Store in the original packaging at a temperature not exceeding 25°C. Keep out of reach of children. Packaging. 10 tablets in a contour cell package; 1 contour cell package in a carton; 10 tablets in contour cell packages. Dispensing regime: Pharmaceutical product group - II, dispensed with prescription form №3.
