Phthalazol

INSTRUCTION FOR MEDICAL USE OF THE MEDICINAL PRODUCT FTHALAZOLE (PHTHALAZOLE)

Composition:

Active ingredient: phthalylsulfathiazole;

1 tablet contains phthalylsulfathiazole 500 mg (0.5 g);

Excipients: potato starch, calcium stearate.

Pharmaceutical form. Tablets.

Main physicochemical properties: white or white with a yellowish tint tablets, with flat surface, a score line and beveled edges.

Pharmacotherapeutic group. Antimicrobial agents used in intestinal infections.

ATC code A07AB02.

Pharmacological properties.

Pharmacodynamics.

Phthalazol is a broad-spectrum sulfonamide agent active against gram-positive and gram-negative microorganisms—the causative agents of intestinal infections. It exerts a bacteriostatic effect. The primary mechanism of action is due to inhibition of the synthesis of microbial growth factors—folic acid and dihydrofolic acid—required for the synthesis of purines and pyrimidines.

Pharmacokinetics.

Phthalazol is slowly absorbed from the gastrointestinal tract; the majority of the drug remains in the small intestine, where it gradually breaks down to form sulfathiazole (norsulfazol), which has high antimicrobial activity. As a result, high concentrations of sulfathiazole are achieved in the intestine, providing effective bacteriostatic action against intestinal flora, thus ensuring the efficacy of phthalylsulfathiazole in intestinal infections. The drug is excreted predominantly in feces. A small amount that is absorbed (5–10% of the dose) is uniformly distributed throughout the body, acetylated in the liver, and excreted in urine.

Clinical characteristics.

Indications.

Acute dysentery (shigellosis), chronic dysentery in the stage of exacerbation, colitis, enterocolitis, gastroenteritis; for prevention of infectious complications during intestinal surgery.

Contraindications.

Increased individual sensitivity to phthalylsulfathiazole, sulfanilamide drugs and/or other components of the drug; Basedow's disease; blood disorders; acute hepatitis.

Interaction with other medicinal products and other types of interactions.

If the patient is taking any other medicinal products, it is necessary to consult a physician regarding the possibility of using the drug.

Depending on the nature of the disease, the drug may be used in combination with antibiotics (an enhanced antimicrobial effect is observed). It is advisable to prescribe simultaneously with Phthalazol sulfanilamides that are well absorbed (sulfadimidine, etazole, etazole-sodium, etc.). Incompatible with PAS (para-aminosalicylic acid), salicylates, and diphenin (increased toxic effect of phthalazol), oxacillin (reduced activity of oxacillin), nitrofurans (increased risk of anemia and methemoglobinemia), male and female sex hormones (suppression of gonadal function), calcium chloride and vitamin K (impaired blood coagulation).

Phthalazol must not be used simultaneously with enterosorbents and laxatives.

Myelotoxic medicinal products enhance the manifestations of hematotoxicity of the drug.

Special precautions.

Before taking the medicinal product, consult a doctor!

Use with caution in patients with nephrosis or nephritis.

During Phthalazol treatment, patients should take vitamin B complex (thiamine, riboflavin, nicotinic acid), as suppression of intestinal flora growth reduces the synthesis of these vitamins.

If symptoms of illness do not begin to subside, or if the condition worsens, or adverse reactions occur, discontinue use of the medicinal product and consult a doctor for further advice on its use.

Use during pregnancy or breastfeeding.

Phthalylsulfathiazole crosses the placenta, and animal studies have shown adverse effects on the fetus; therefore, the drug should not be used during pregnancy.

Phthalylsulfathiazole passes into breast milk and may cause kernicterus in infants, as well as hemolytic anemia in infants with glucose-6-phosphate dehydrogenase deficiency; therefore, the drug should not be used during breastfeeding.

Ability to influence reaction speed when driving or operating machinery.

The medicinal product does not affect psychomotor reaction speed and may be used at recommended doses by individuals who drive vehicles or operate machinery.

Dosage and Administration.

Do not use the medicinal product for longer than the specified period without consulting a physician!

Administer orally to adults and children aged 3 years and older.

Adults and children aged 12 years and older.

For acute dysentery, administer to adults and children aged 12 years and older as follows:
Days 1–2: 6 g per day (1 g every 4 hours),
Days 3–4: 4 g per day (1 g every 6 hours),
Days 5–6: 3 g per day (1 g every 8 hours).
The total treatment course dose is 25–30 g.

Five to six days after completion of the first treatment course, initiate a second course:
Days 1–2: 1 g every 4 hours (during night hours – every 8 hours), total 5 g per day;
Days 3–4: 1 g every 4 hours (do not administer at night), total 4 g per day;
Day 5: 1 g every 4 hours (do not administer at night), total 3 g per day.
The total dose for the second course is 21 g; in mild cases, the dose may be reduced to 18 g.

Maximum doses for adults: single dose – 2 g, daily dose – 7 g.

For treatment of other diseases, administer to adults 1–2 g every 4–6 hours during the first 2–3 days, and 0.5–1 g every 4–6 hours during the following 2–3 days.

Children aged 3 to 12 years.

For acute dysentery:
Children aged 3 to 7 years: 500 mg per dose, 4 times daily;
Children aged 7 to 12 years: 500–750 mg per dose, 4 times daily.
Treatment course duration: up to 7 days.

For treatment of other diseases: on the first day, administer at a dose of 100 mg/kg body weight per day, divided into equal doses every 4 hours, with a pause at night. In subsequent days, administer 250–500 mg every 6–8 hours. Treatment course duration: up to 7 days.

If a child cannot swallow the tablet, it should be crushed and dissolved in a small amount of cooled boiled water.

Children.

For use in children aged 3 years and older.

Overdose.

Symptoms: macrocytosis and pancytopenia due to folic acid deficiency may occur. This can be prevented by administering folic acid or calcium folinate. Exacerbation of adverse reactions.

Treatment: discontinue the drug, symptomatic therapy.

Adverse Reactions.

If any adverse effects occur, consult a physician immediately!

Systemic adverse effects typical of sulfonamides are rare due to the low absorption of the active substance.

Possible adverse reactions:

Immune system: hypersensitivity reactions, including allergic reactions such as fever, rash, and itching;

Blood system: agranulocytosis, aplastic anemia;

Other: vitamin B complex deficiency (thiamine, riboflavin, nicotinic acid) due to suppression of intestinal microflora.

Shelf life: 5 years.

Do not use after the expiry date stated on the packaging.

Storage conditions.

Store in the original packaging at a temperature not exceeding 25 °C.

Keep out of reach of children.

Packaging.

10 tablets per blister pack.

10 tablets in a blister; 1 or 10 blisters in a cardboard box.

Dispensing category.

Over-the-counter: No. 10, No. 10х1.

By prescription: No. 100 (10х10).

Manufacturer.

JSC "CHIMFARMZAVOD "CHERVONA ZIRKA".

Manufacturer's address and place of business.

Ukraine, 61010, Kharkiv region, city of Kharkiv, Gordeyevskaya Street, 1.