Phenystil, drops 1 mg/ml 20 ml

Pharmacological action – antihistamine, anti-allergic, antipruritic.

Pharmacodynamics

Antihistamine, anti-allergic and antipruritic agent. Blocker of H1-histamine receptors, is a competitive histamine antagonist.

The drug reduces increased capillary permeability associated with allergic reactions. It also has anti-bradykinin and weak m-cholin-blocking effects. A slight sedative effect may be noted when taking the drug in the daytime.

Pharmacokinetics

It is quickly and completely absorbed when taken orally.

The bioavailability is about 70%.

The Tmax of dimethindene in plasma after oral administration of drops is 2 hours. Binding with plasma proteins is 90%. It penetrates into the tissues well. Metabolized in the liver through hydroxylation and methoxylation. T1/2 is 6 hours. It is excreted in the bile and urine (90% – as metabolite and 10% – unchanged).

Indications

Skin itching, Allergic rhinitis, Dermatosis, Pollinosis, Insect bites, Allergy, Allergic conjunctivitis, Urticaria, Eczema, Dermatitis

– Allergic diseases (urticaria, hay fever, year-round allergic rhinitis, angioedema, food and drug allergies);

– skin itching of different origin (eczema, pruritic dermatosis, including atopic dermatitis.

– prevention of allergic reactions during hypersensitization therapy.

Active ingredient

Dimethinden

Composition

Active ingredient: dimethindene maleate 1.0 mg.

1 ml of drops for oral administration contains 1 mg of dimethindene.

Auxiliary substances:

Sodium hydrophosphate dodecahydrate 16.0 mg, citric acid monohydrate 5.0 mg, benzoic acid 1.0 mg, edetate disodium 1.0 mg, sodium saccharinate 0.5 mg, propylene glycol 100.0 mg, purified water 888.5 mg.

How to take, the dosage

The drug is administered orally.
In children aged from 1 month to 12 years old a daily dose of 100 mcg/kg of body weight, which is equivalent to 2 drops per kg of body weight, is recommended. The daily dose should be divided into 3 intakes.

In children aged 1 month to 1 year the drug should be used only by prescription and in case of indications for use of histamine H1-receptor blockers.

In children over 12 years and adults the recommended daily dose is 3-6 mg (60-120 drops) divided into 3 intakes, i.e. 20-40 drops.i.e. 20-40 drops 3 times a day.

Patients prone to sleepiness are recommended to prescribe 40 drops before going to bed and 20 drops in the morning.
20 drops = 1 ml = 1 mg dimethinden.

For elderly patients (over 65 years) dosage adjustment is not required.

Interaction

Accelerates the effect of anxiolytics, sleeping pills.

In case of concomitant use of ethanol – slower psychomotor reactions.

Tricyclic antidepressants and m-cholinoblockers increase the risk of increased IOP.

MAO inhibitors increase anticholinergic and CNS depressant effects.

Special Instructions

Phenystil® Drops should not be exposed to heat; if prescribed for infants, they should be added to a bottle of warm baby food immediately before feeding. If the baby is already being spoon-fed, the drops can be given undiluted. The drops have a pleasant taste. If used in children under 1 year of age, consult a doctor and use only if indicated to use H1-histamine receptor blockers. Do not exceed the recommended dose. Ineffective in itching associated with cholestasis.

Impact on the ability to drive and operate machinery. Similar to other antihistamines, Phenystil® may impair attention, so it should be taken with caution when driving, operating machinery, or other activities where increased attention is required.

Synopsis

Drops for oral administration as a clear colorless liquid, almost odorless.

Contraindications

– hypersensitivity to dimethindene and other components of the drug;

– closed-angle glaucoma;

– bronchial asthma;

– prostatic hyperplasia;

– pregnancy (1st trimester);

– lactation;

– children (under 1 month).

With caution: chronic obstructive pulmonary diseases; children under 1 year of age, because the sedative effect may be accompanied by episodes of nocturnal apnea.

Side effects

Drowsiness (especially at the beginning of treatment), nausea, dry mouth and throat, dizziness, agitation, headache, edema, skin rash, muscle spasm, disorders of external respiration.

Overdose

Symptoms: CNS depression and somnolence (mainly in adults), CNS stimulation and m-cholinoblocking effects (especially in children), including agitation, ataxia, tachycardia, hallucinations, tonic-clonic seizures, mydriasis, dry mouth, flushes to the face, urinary retention and fever; BP decrease, collapse.

Treatment: administration of activated charcoal, saline laxatives, drugs to support cardiac and respiratory system activity (analeptic drugs should not be used).

Pregnancy use

Fenistil® is contraindicated in I trimester of pregnancy and during lactation (breastfeeding).

Fenistil® use in II and III trimesters of pregnancy is possible under medical supervision only if the expected benefits to the mother exceed the potential risk to the fetus.

Similarities

Phenystil, Dimethinden, Phenismart