Histaphene

Histafen (sehifenadine) is an antihistamine used to treat allergic reactions. Sehifenadine acts as a histamine H1 receptor blocker, helping to reduce symptoms caused by the release of histamine in the body, such as itching, runny nose and eye irritation.

In a study of the use of Histaphene in patients with senile pruritus, the drug was shown to provide significant improvement in the majority of patients, reducing symptoms of pruritus and improving quality of life (Dudun & Polion, 2019).

Histafene may be an effective option for treating allergic reactions in patients who require histamine receptor blockade to reduce or prevent allergy symptoms.

Indications Histaphene

1. Allergic runny nose (hay fever): Histaphene may help relieve nasal congestion, runny nose, sneezing and itchy nose caused by a reaction to pollen, dust, animal dander and other allergens.
2. Seasonal allergic rhinitis (hay fever): This medication may be used to treat symptoms caused by an allergic reaction to seasonal allergens, such as grass and tree pollen.
3. Allergic conjunctivitis: Histaphene may help relieve itchy, red, and watery eyes caused by allergic conjunctivitis, such as from contact with dust, pollen, or animals.
4. Urticaria (urticaria): The drug may be effective in relieving itching, redness, and swelling of the skin associated with hives or other allergic skin reactions.
5. Other allergic conditions: Histaphene may also be used to treat other allergic conditions, including allergic reactions to insect stings, allergic dermatitis and allergic reactions to food, provided that the drug has been prescribed by a doctor.

Release form

Histafen is usually available in the form of tablets for oral administration.

Pharmacodynamics

1. Mechanism of action:

   • Setifenadine is an antihistamine that blocks peripheral histamine H1 receptors.
   • Histamine is a substance that is released in the body in response to an allergic reaction. Under the influence of histamine, symptoms such as itching, runny nose, red eyes and other signs of an allergic reaction may occur.
   • Blocking histamine H1 receptors with setifenadine prevents the action of histamine, which leads to a decrease or disappearance of allergic symptoms.

Pharmacokinetics

1. Absorption: Seccifenadine is usually well absorbed from the gastrointestinal tract after oral administration. Maximum plasma concentrations are usually achieved 2-4 hours after administration.
2. Metabolism: The main route of metabolism of seccifenadine is oxidation in the liver, carried out by the enzyme cytochrome P450 3A4. The main metabolites are desloratadine and 3-hydroxy-desloratadine. Desloratadine also has antihistamine properties and is independently used in the treatment of allergies.
3. Excretion: Metabolites of seccifenadine and seccifenadine itself are excreted primarily in urine and feces. In healthy adult patients with a complete glomerular filtration ratio, the pharmacokinetics of seccifenadine are not altered, and in patients with impaired renal function (especially severe impairment), a delay in elimination may be observed.
4. Half-life: The half-life of sectionifenadine from the body is about 14 hours, which allows it to be taken once or twice a day, depending on the doctor’s recommendations and the form of the drug.
5. Effect of food: Eating food, especially fatty foods, may slow down the absorption of seccifenadine, but does not have a significant effect on its overall bioavailability.
6. Interactions with other drugs: Seccifenadine may interact with other drugs, including drugs metabolized through the cytochrome P450 3A4 system, such as macrolide antibiotics, protease inhibitors and others.

Dosing and administration

1. Method of application:

   • Histafen is usually taken orally, i.e. Through the mouth.
   • Tablets are usually swallowed whole with a small amount of water.
   • The drug can be taken regardless of meals.

2. Dosage:

   • The dosage of Histafen may vary depending on the patient's age, weight, and severity of allergy symptoms.
   • The usual recommended dose for adults and children over 12 years of age is 60 mg taken once daily.
   • For children aged 6 to 12 years, a dose of 30 mg, also taken once daily, is usually recommended.
   • For children aged 2 to 6 years, a dose of 15 mg taken once daily is usually recommended.
   • For children under 2 years of age, it is recommended to consult a doctor before using Histaphen.

3. Duration of treatment:

   • The duration of taking Histafen is usually determined by the doctor depending on the nature and severity of allergic symptoms.
   • The drug is usually taken for the duration of the patient's exposure to the allergen, but the decision about the duration of treatment must be made by the doctor.

Use Histaphene during pregnancy

The use of sequifenadine (Histafen) during pregnancy is not recommended due to a lack of data on its safety for the developing fetus. Questions remain in the scientific literature regarding the effects of sequifenadine on pregnancy and fetal development.

Although direct studies of sequifenadine are limited, studies of other antihistamines such as terfenadine (a structural analogue of sequifenadine) have shown that its use during pregnancy is not associated with an increased risk of major birth defects. However, studies have noted that neonates exposed to terfenadine had slightly lower mean birth weights compared to controls (Loebstein et al., 1999).

Based on these data, it is recommended to avoid the use of terfenadine during pregnancy, especially without consulting a physician who can assess the potential risks and benefits of its use based on the individual clinical situation.

Contraindications

1. Hypersensitivity: People with a known hypersensitivity to sequifenadine or any other ingredients of the drug should not take Histaphene.
2. Use of CYP3A4 enzyme inhibitors: Use of sequifenadine in combination with CYP3A4 enzyme inhibitors, such as ketoconazole or erythromycin, may increase the blood levels of sequifenadine and increase the risk of cardiovascular side effects.
3. Increased risk of cardiovascular complications: Sejifenadine may increase the risk of cardiovascular complications, especially in people with heart disease, arrhythmias, or those taking other medications that may affect heart rhythm.
4. Pregnancy and breastfeeding: Data on the safety of sejifenadine during pregnancy and breastfeeding are limited, therefore its use during this period should only be carried out as prescribed by a doctor.
5. Children: Sehifenadine is not recommended for children under 6 years of age without consulting a doctor.
6. Hepatic Impairment: Patients with severe hepatic impairment should avoid sequifenadine or use it with caution under medical supervision.
7. Alcohol intake: Drinking alcohol while taking sequifenadine may increase some of its side effects, such as drowsiness and central nervous system depression.

Side effects Histaphene

1. Drowsiness or tiredness: Some people may feel drowsy or tired after taking Histaphene. This side effect may be exacerbated by concomitant use of alcohol or other sedatives.
2. Dizziness: Some patients may experience dizziness or instability after taking the drug.
3. Dry mouth: Some people may experience dry mouth after taking Histaphen.
4. Stomach upset: Stomach upset such as nausea, vomiting, diarrhea, or constipation may occur.
5. Insomnia or restlessness: Taking Histaphene may cause insomnia or restlessness in some people.
6. Rare side effects: In rare cases, more serious side effects such as allergic reactions, muscle pain, impotence or memory problems may occur.

Overdose

Symptoms of histaphene overdose may include:

1. Drowsiness or fatigue.
2. Dizziness or instability.
3. Dry mouth.
4. Stomach pain or discomfort in the stomach.
5. Rarely, more serious symptoms such as rapid heartbeat, difficulty breathing, or even seizures are possible.

Interactions with other drugs

1. Drugs metabolized via cytochrome P450 3A4: Secifenadine is metabolized in the liver via the enzyme cytochrome P450 3A4. Drugs that are inhibitors or inducers of this enzyme may affect the metabolism of secifenadine. For example, cytochrome P450 3A4 inhibitors such as ketoconazole, erythromycin, or ritonavir may increase the blood concentration of secifenadine, which may increase its effects and increase the risk of adverse effects.
2. Alcohol: Drinking alcohol with secifenadine may increase its sedative effects, causing increased drowsiness and lethargy.
3. Other centrally acting drugs: Secifenadine may enhance the sedative effects of other centrally acting drugs such as hypnotics, antianxiety drugs, and antidepressants. This may increase the risk of side effects such as drowsiness and lethargy.
4. Antihistamines: Taking secifenadine with other antihistamines may increase their effects, which may also increase the risk of side effects.
5. Medicines that increase gastrointestinal pH: Medications such as antacids or heartburn medications may affect the rate and extent of absorption of secifenadine from the gastrointestinal tract, which may decrease its effectiveness.