Sulfadimethoxin, tablets 500 mg, 10 pcs.

Pharmacotherapeutic group: Antimicrobial agent, sulfonamide

ATX code: J01ED01

Pharmacological properties

.Pharmacodynamics

An antimicrobial bacteriostatic agent. Mechanism of action is due to competitive antagonism with para-aminobenzoic acid, inhibition of dihydropteroate synthetase, disruption of tetrahydrofolic acid synthesis, required for purine and pyrimidine synthesis. Active against Gram-positive and Gram-negative microorganisms: Staphylococcus spp., Streptococcus spp. including Streptococcus pneumoniae, Friedlander’s bacillus, Escherichia coli, Shigella spp, Chlamydia trachomatis.

Pharmacokinetics

In oral administration it is absorbed relatively slowly, detected in blood after 30 minutes. When single administration (in a dose of 1 – 2 g), time to reach maximum concentration in blood (T_Cmax) – 8 – 12 h.

Therapeutic concentration in adults is noted when taking 1-2 g on the first day and 0.5-1 g on the following days. Blood protein binding is 90-99%.

The drug is accumulated in blood, primarily due to a high degree of binding to blood proteins (90-99%). It is well distributed through the organs and systems. But unlike other representatives of long-acting sulfonamides, it poorly penetrates through the blood-brain barrier (BBB) and its concentration in the cerebrospinal fluid is low. However, in inflammation of meningeal membranes the permeability of the GEB increases sharply.

It penetrates well into the pleural fluid (60-90% of its concentration in blood), in the biliary system, where its concentrations are 1.5-4 times higher than in blood. Primarily metabolism is realized by microsomal glucuronidation pathway, which is connected with cytochrome P450 and NADPH-dependent.

The strong connection with blood plasma proteins and high reabsorption in renal tubules (93-97,5%) promotes slow excretion of preparation from the body.

The blood contains 5-15% of acetylated metabolites, the urine contains 10-25% of acetyl derivatives and 75-90% of sulfadimethoxin glucuronide; the latter is well soluble and does not provoke crystalluria. The acetyl derivative is not reabsorbed and is completely excreted by the kidneys. After 24 hours 20-44% of the taken dose is excreted, after 48 hours – up to 56%, after 96 hours – up to 83.3%.

Indications

Active ingredient

Composition

Active ingredient:sulfadimethoxin – 500.0 mg.

Supplementary substances: Microcrystalline cellulose – 42.0 mg, crosspovidone (type B) – 26.5 mg, povidone K 25 (polyvinylpyrrolidone medium molecular K 25) – 25.5 mg, calcium stearate – 6.0 mg.

How to take, the dosage

Ingestion, once daily.

In adults, on the first day 1 to 2 g, then 0.5 to 1 g/day.

In children from 12 to 18 years: the initial and maintenance doses are 1 g and 0.5 g respectively.

After normalization of temperature the drug is used in maintenance doses for 2 to 3 days more. The course of treatment, depending on the severity of the disease is 7-14 days.

Interaction

Sulfadimethoxin reduces the effectiveness of bactericidal antibiotics acting only on fissile microorganisms (including penicillins, cephalosporins).

Special Instructions

During treatment it is recommended to drink plenty of alkaline fluids, monitor blood and urine parameters.

It is used externally as part of the combination therapy.

Contraindications

Side effects

CNS disorders: headache possible.

Digestive system disorders: dyspeptic symptoms, nausea, vomiting, cholestatic hepatitis.

Allergic reactions: skin rashes, drug fever.

Hematopoietic system: rarely – leukopenia, agranulocytosis.