Instructions for use Histafen tablets 50 mg No. 20
Composition
active ingredient: sexifenadine;
1 tablet contains 50 mg of sexifenadine hydrochloride as anhydrous substance;
Excipients: lactose monohydrate; microcrystalline cellulose, corn starch, colloidal anhydrous silicon dioxide, magnesium stearate.
Dosage form
Pills.
Main physicochemical properties: flat-cylindrical tablets of white or almost white color with a bevel and a score on one side of the tablet.
Pharmacotherapeutic group
Antihistamines for systemic use. ATX code R06A X32.
Pharmacological properties
Pharmacodynamics
Sexifenadine is a blocker of H1 receptors, as well as a moderate blocker of 5HT1-serotonin receptors, thus, it weakens the action of mediators of allergy histamine and serotonin. A feature of the drug is that it has an antihistamine effect not only by blocking H1 receptors, but also by reducing the content of histamine in tissues by accelerating its metabolism by the enzyme diamine oxidase, which breaks down endogenous histamine. Sexifenadine prevents or weakens the spasmogenic effect of histamine and serotonin on the smooth muscles of the bronchi, intestines, blood vessels, reduces capillary permeability, and has a pronounced antipruritic effect. Sexifenadine affects the body's immunological reactivity, reducing the number of antibody-forming and rosette-forming cells in the spleen, bone marrow, and lymph nodes, and also reduces the increased concentration of immunoglobulins of classes A and G.
The drug penetrates poorly through the blood-brain barrier, which explains the lack of a pronounced inhibitory effect on the central nervous system, however, in some cases, with individual hypersensitivity to the drug, a mild sedative effect may be noted. Sexifenadine does not affect the biochemical parameters of blood and urine (including the concentration of glucose and cholesterol in the blood), blood pressure, electrocardiogram parameters, does not increase the latent period of the conditioned reflex and does not affect the electroencephalogram parameters.
Pharmacokinetics
The drug is rapidly absorbed from the gastrointestinal tract. The maximum concentration in the blood plasma is reached after 1-2 hours. It is metabolized in the liver, forming a pharmacologically inactive metabolite. After a single dose of 50 mg, the half-life is 12 hours, and after repeated doses it decreases to 5.8 hours. The use of the drug does not cause cumulation. More than 20% of the dose is excreted by the kidneys and 50% - by the intestines. About 30% of the dose is excreted unchanged, 40-50% - in the form of metabolites.
Indication
Acute and chronic allergic diseases in adults: hay fever, allergic rhinitis, rhinosinusopathies (atopic and infectious-allergic); allergic reactions associated with the use of medicines, food products, household chemicals.
Allergic and non-allergic diseases accompanied by skin itching (allergic or atopic dermatitis, skin vasculitis, neurodermatitis, lichen planus) in adults. Atopic and infectious-allergic dermatitis in children aged 12 years and older.
Prevention of allergic diseases (before seasonal exacerbation) and maintenance therapy in adults.
Contraindication
Hypersensitivity to sexifenadine or to any of the excipients of the drug, bronchial asthma attacks.
The use of antihistamines is contraindicated in patients taking monoamine oxidase inhibitors (MAOIs).
Contraindicated during pregnancy and breastfeeding.
Interaction with other medicinal products and other types of interactions
The use of Histafen can be combined with treatment with other medications for topical use (ointments, compresses, eye drops, nasal drops).
Histafen does not enhance the depressant effect of hypnotics and drugs containing ethanol on the central nervous system.
The use of the drug is contraindicated with simultaneous use of MAO inhibitors.
Application features
Caution should be exercised in patients with impaired renal function (treatment should begin with a minimum dose), with severe diseases of the cardiovascular system, digestive tract, and liver.
There are no clinical trial data on the use of the drug in the elderly.
The drug contains lactose, therefore patients with rare hereditary forms of galactose intolerance, lactase deficiency or glucose-galactose malabsorption syndrome should not use the drug.
During treatment, you should refrain from drinking alcohol.
Ability to influence reaction speed when driving vehicles or other mechanisms
Persons whose work requires rapid physical and mental reactions (transport drivers) should first determine (by short-term administration) whether the drug has a hypnotic effect on them. In case of a sedative effect, one should refrain from driving.
Use during pregnancy or breastfeeding
During breastfeeding, the use of antihistamines is not recommended due to the possibility of negative effects on the child's central nervous system.
If necessary, use of the drug should stop breastfeeding.
Method of administration and doses
Take Histafen orally, after meals, with water.
Adults
Acute chronic allergic diseases: 50-100 mg 2-3 times a day.
Allergic and non-allergic diseases accompanied by skin itching: 50-100 mg 2-3 times a day.
Usually the therapeutic effect occurs 3 days after the start of treatment. The duration of the treatment course is 5-15 days. If necessary, repeat the treatment course.
Prevention of allergic diseases (before seasonal exacerbation) and maintenance therapy: 50 mg 2 times a day. For prevention, it is recommended to start taking the drug 2 weeks before the expected allergic reaction.
If one or more doses of the drug are missed, treatment should be continued at the previously prescribed doses.
Children aged 12 and over
Atopic and infectious-allergic dermatitis: 50 mg 3 times a day. The course of treatment is 7 days.
Children
Use the drug in children over 12 years of age for atopic and infectious-allergic dermatitis.
Overdose
The drug is low-toxic.
Symptoms: dry mucous membranes, headache, vomiting, abdominal pain and other dyspeptic phenomena.
Treatment: symptomatic therapy. Specific antidote is unknown.
Adverse reactions
Like all medicines, Histafen can cause side effects, although not everybody gets them.
Classification of the frequency of adverse reactions: 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).
From the blood and lymphatic system: rarely - leukopenia.
On the part of the digestive tract: often - dry mouth; infrequently - mild pain in the epigastric region, dyspeptic phenomena (especially after taking the drug on an empty stomach), very rarely - increased appetite.
In people with chronic diseases of the digestive tract, the frequency of these adverse reactions increases.
Adverse reactions resolve within the first days of treatment and do not require discontinuation of the drug or a significant dose reduction.
From the nervous system: often - drowsiness (on average - in 13.3% of patients) is dose-dependent; at doses of 150 mg per day, drowsiness is observed in 1.97% of patients, when the dose is increased to 400 mg per day - in 24.6% of patients. In most cases, drowsiness decreases or disappears 2-5 days after the start of treatment. Histafen can improve sleep in patients suffering from insomnia due to itching; infrequently - headache; rarely - insomnia, mental disorders (agitation) - when using the drug in high doses.
On the part of the kidneys and urinary tract: rarely - weak diuretic effect.
From the reproductive system: rarely - menstrual cycle disorders.
Expiration date
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 blister. 2 blisters in a cardboard pack.
Vacation category
Without a prescription.
Producer
JSC "Olainfarm" / JSC "Olainfarm".
Location of the manufacturer and its business address
5 Rupnicu street, Olaine, LV-2114, Latvia.
