Phencarol^® (Tablets, Solution) Instructions for Use

ATC Code

R06AX31 (Quifenadine)

Active Substance

Quifenadine (Rec.INN registered by WHO)

Clinical-Pharmacological Group

Histamine H₁-receptor blocker. Antiallergic drug

Pharmacotherapeutic Group

Systemic antihistamines; other systemic antihistamines

Pharmacological Action

Histamine H₁-receptor blocker. Prevents the development and alleviates the course of allergic reactions. It has antiallergic, antiexudative, and antipruritic effects, preventing the development of allergic inflammation in tissues.

It weakens the action of histamine, reduces its effect on vascular permeability (by reducing permeability, it has an anti-edema effect), reduces its bronchospastic effect and spasmogenic effect on intestinal smooth muscles, and weakens the hypotensive effect of histamine.

Quifenadine reduces the histamine content in tissues (associated with its ability to activate diamine oxidase, an enzyme that inactivates histamine). During course treatment, the antihistamine effect of quifenadine does not decrease.

It has a moderate antiserotonin effect and exhibits weak m-cholinoblocking activity. It does not have a depressant effect on the CNS.

Pharmacokinetics

Absorption and Distribution

Quifenadine is rapidly absorbed from the gastrointestinal tract, absorption is 45%, and it is detected in body tissues within 30 minutes.

C_max in blood plasma is reached within 1 hour. It has low lipophilicity and poorly penetrates the blood-brain barrier.

The highest concentration of the active substance is found in the liver, a slightly lower one in the lungs and kidneys, and the lowest in the brain (less than 0.05%, which explains the absence of a pronounced sedative and hypnotic effect).

Metabolism and Excretion

Quifenadine is metabolized in the liver.

Metabolites are excreted by the kidneys and intestines. The unabsorbed part of the drug is excreted through the intestines.

Indications

• Pollinosis;
• Acute and chronic urticaria;
• Angioneurotic edema;
• Allergic rhinitis;
• Dermatoses (including eczema, psoriasis, atopic dermatitis);
• Neurodermatitis;
• Skin itching.

ICD codes

Dosage Regimen

Solution

It is used orally and intramuscularly. The dosage regimen is set individually. The dose, method and scheme of application, and duration of therapy are determined depending on the indications, clinical situation, patient’s age, and the dosage form used.

Tablets

Take orally after meals.

The dosing schedule is the same for all indications for use. The dosing of quifenadine can be influenced by the severity of the allergic reaction, individual patient sensitivity, as well as the severity of possible side effects.

For adults – 50 mg 1-4 times/day or 25 mg 2-4 times/day. The maximum daily dose is 200 mg. The course of treatment averages 10-20 days. If necessary, the course of treatment is repeated.

For children aged 3 to 7 years – 10 mg 2 times/day; aged 7 to 12 years – 10-15 mg 2-3 times/day; over 12 years – 25 mg 2-3 times/day. The course of treatment is 10-15 days.

Adverse Reactions

From the digestive system dry oral mucosa, nausea, vomiting.

From the CNS drowsiness, headache.

Other allergic reactions.

Contraindications

• Hypersensitivity to quifenadine;
• Pregnancy;
• Lactation period (breastfeeding);
• Children under 3 years of age (for 10 mg and 25 mg tablets);
• Children and adolescents under 18 years of age (for 50 mg tablets);
• Sucrase/isomaltase deficiency, fructose intolerance, glucose-galactose malabsorption, because the dosage form contains sucrose.

With caution

Diseases of the gastrointestinal tract, liver, and kidneys.

Use in Pregnancy and Lactation

Contraindicated for use during pregnancy and breastfeeding.

Use in Hepatic Impairment

Should be used with caution in liver diseases.

Use in Renal Impairment

Should be used with caution in kidney diseases.

Pediatric Use

The use of quifenadine in the form of 10 mg and 25 mg tablets is contraindicated in children under 3 years of age, in the form of 50 mg tablets – in children and adolescents under 18 years of age.

Special Precautions

The absence of a pronounced m-cholinoblocking effect allows the use of Quifenadine in patients for whom antihistamines with m-cholinoblocking activity are contraindicated.

Use in pediatrics

Children are recommended to use Quifenadine in the form of 10 mg or 25 mg tablets.

Effect on ability to drive vehicles and operate machinery

Quifenadine is approved for use by persons whose work requires increased concentration and rapid psychomotor reactions (driving vehicles and working with machinery), however, it is recommended to first determine (by short-term prescription) whether this agent has a sedative effect.

Drug Interactions

Quifenadine does not enhance the depressant effect of ethanol and hypnotics on the CNS.

Possessing weak m-cholinoblocking properties, the drug may reduce gastrointestinal motility, which contributes to increased absorption of slowly absorbed drugs (for example, indirect anticoagulants – coumarins).

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Over-the-Counter

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.