Phthalazole, tablets 500 mg 10 pcs

An antibacterial agent, a sulfonamide derivative. It has a wide range of antimicrobial activity. Phthalylsulfathiazole is active against Gram-positive and Gram-negative microorganisms, including pathogens of intestinal infections. It is poorly absorbed from the gastrointestinal tract. It acts mainly in intestine lumen, where gradual release of sulfonamide part of the molecule occurs.

The mechanism of action is connected with competitive antagonism with PABA and competitive inhibition of dihydropteroate synthetase, which leads to disruption of synthesis of tetrahydrofolic acid necessary for synthesis of purines and pyrimidines.

Indications

Active ingredient

Composition

1 tablet contains:

the active ingredient:

Phthalylsulfathiazole 500 mg.

How to take, the dosage

Inside

In acute dysentery:

Adults in the first 1-2 days – 1 g 6 times a day, in the 3rd-4th days – 1 g 4 times a day, in the 5th-6th days – 1 g 3 times a day. The average course dose is 25-30 g. After 5-6 days, carry out the second course of treatment: Days 1-2 – 1 g 5 times a day (during the day – every 4 hours, at night – 8 hours), 3-4 days – 1 g 4 times a day (at night not given), 5 day – 1 g 3 times a day. The total dose in the second cycle – 21 g, with a mild course – 18 g. Maximal dose for adults: single dose 2 g, daily dose 7 g.

In children under 3 years of age – 0.2 g/kg in 3 doses for 7 days, over 3 years – 0.4-0.75 g 4 times a day.

In other infections:

Adults are prescribed 1-2 g every 4-6 hours for the first 2-3 days, half doses for the next 2-3 days;

Children – 0.1 g/kg/day in equal doses every 4 hours with an overnight break, 0.2-0.5 g every 6-8 hours for the following days.

Interaction

The following interactions may be observed when using phthalazole together with other medicinal products.

PASC and barbiturates: the activity of sulfonamides is increased.

Thioacetasone, levomycetin: the possibility of agranulocytosis increases.

Nitrofurans: increased risk of anemia and methemoglobinemia.

Indirect anticoagulants: increased anticoagulant effect.

Oxacillin: decreases antibiotic activity.

The combined use of phthalazole with acids and acid-reacting drugs, hexamethylentetramine, adrenaline solution is not advisable because they are chemically incompatible.

When phthalazole is used in combination with drugs containing PABA esters (novocaine, anesthesin, dicaine), the antibacterial activity of sulfonamide is inactivated through a competitive mechanism. The effect is enhanced by antibiotics and well-absorbed sulfonamides.

Special Instructions

If necessary, the drug is combined with antibiotics.

Contraindications

Side effects

Nervous system disorders: headache, dizziness, depressed mood.

System disorders: myocarditis, cyanosis.

Blood system disorders: in rare cases – leukopenia, thrombocytopenia, agranulocytosis, erythrocyte hemolysis. With prolonged use anemia may occur due to deficiency of pantothenic and pteroylglutaric acids produced by microbial cells.

Gastrointestinal disorders: nausea, vomiting, diarrhea, oral disorders (including stomatitis, gingivitis, glossitis), gastritis, cholangitis, hepatitis, vitamin B deficiency (due to suppression of intestinal microflora).

Respiratory system: eosinophilic pneumonia.

Urinary system disorders: urolithiasis.

Allergic and toxic-allergic reactions: drug allergy, including skin manifestations of drug allergy in the form of various rashes up to erythema multiforme and nodular, in some cases – epidermal necrolysis (Lyell’s syndrome). In some cases, allergic edema of the lips and face and periarteritis nodosa occur.