Histafen® [SeQuifenadine]

Pharmacological properties

seQuifenadine is a blocker of H1 receptors, as well as a moderate blocker of 5nt1 serotonin receptors, thereby reducing the severity of the effects of histamine and serotonin allergy mediators. a feature of the drug is that it has an antihistamine effect not only due to blockade of the H1 receptors, but also by reducing the concentration of histamine in tissues due to the acceleration of its metabolism by the enzyme diamine oxidase, which breaks down endogenous histamine. seQuifenadine prevents or reduces the severity of 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. seQuifenadine affects the immunological reactivity of the body, reducing the number of antibody-forming and rosette-forming cells in the spleen, bone marrow, lymph nodes, and also reduces the increased concentration of immunoglobulins of classes a and g.

The drug penetrates poorly through the BBB, which explains the absence of a pronounced inhibitory effect on the central nervous system, however, in some cases, with individual hypersensitivity to the drug, a slight sedative effect may be noted. SeQuifenadine does not affect the biochemical parameters of blood and urine (including the concentration of glucose and cholesterol in the blood), blood pressure, ECG, does not increase the latent period of the conditioned reflex and does not affect the EEG.

Pharmacokinetics The drug is rapidly absorbed in the digestive tract. C_max in 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 T_½ from blood plasma is 12 hours, and after repeated doses of T_½ decreases to 5.8 hours. The use of the drug does not cause cumulation phenomena. 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.

Indications

Acute and chronic allergic diseases: hay fever, allergic rhinitis, rhinosinusopathies (atopic and infectious-allergic); allergic reactions associated with the use of drugs, food products, household chemicals; allergic and non-allergic diseases that are accompanied by skin itching (allergic or atopic dermatitis, skin vasculitis, neurodermatitis, lichen planus); atopic and infectious-allergic dermatitis in children from the age of 12 years; prevention of allergic diseases (before the period of seasonal exacerbation) and maintenance therapy.

Application

Take orally after a meal with water.

Adults

Acute and 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.

The therapeutic effect usually develops after 3 days from the start of therapy. The duration of treatment is 5-15 days. If necessary, repeat the treatment.

Prevention of allergic diseases (before the period of their seasonal exacerbation) and for maintenance therapy: 50 mg 2 times a day. It is recommended to start taking the drug 2 weeks before the expected allergic reaction. If one or more doses of the drug is missed, treatment is continued at the previously prescribed doses.

Children over 12 years old

Atopic and infectious-allergic dermatitis: 50 mg 3 times a day. The course of treatment is 7 days.

Contraindications

Hypersensitivity to seQuifenadine and other components of the drug, BA attacks, the period of pregnancy and lactation, while taking MAO inhibitors.

Side effects

Histafen is usually well tolerated.

Adverse reactions are possible:

from the digestive tract: dry mouth, soreness in the epigastric region, dyspeptic symptoms (especially after taking the drug on an empty stomach); in isolated cases - increased appetite (especially in the first days of treatment, drug withdrawal or a significant reduction in its dose is not required);

from the blood system: leukopenia;

from the nervous system: headache, drowsiness (in most cases, drowsiness decreases or disappears after 2–5 days from the start of treatment), rarely - agitation, insomnia (most often when using the drug in a high dose);

others: menstrual irregularities, mild diuretic effect.

special instructions

Caution should be exercised when prescribing the drug to patients with impaired renal function (treatment begins with the appointment of a minimum dose), severe diseases of the cardiovascular system, gastrointestinal tract, and liver.

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 should refrain from drinking alcohol.

Use during pregnancy and lactation. The safety of seQuifenadine during pregnancy has not been established. Therefore, the drug is contraindicated in women during this period. During breastfeeding, the use of antihistamines is not recommended due to the possibility of a negative effect on the central nervous system of an infant. If necessary, use of the drug should stop breast-feeding. There are no clinical data on the use of the drug in children, so the drug is not prescribed to patients of this age category.

Children. The drug is used in children over the age of 12 years with atopic and infectious-allergic dermatitis.

The ability to influence the reaction rate when driving vehicles or other mechanisms. Persons whose work requires the speed of physical and mental reactions (drivers of vehicles, etc.) must first establish (by means of short-term use) whether the drug causes sedation. With a sedative effect, one should refrain from driving vehicles.

Interactions

The use of histafen can be combined with the use of topical preparations (ointments, compresses, eye drops, nose drops). histafen does not enhance the inhibitory effect of sleeping pills and drugs containing alcohol on the central nervous system. the use of the drug while taking MAO inhibitors is contraindicated.

Overdose

The drug is low toxic. symptoms: dry mucous membranes, headache, vomiting, abdominal pain and dyspeptic symptoms. treatment: symptomatic therapy. special antidote unknown.

Storage conditions

In a dry, dark place at a temperature of no higher than 25 ° c.