Index of drugs

Combination therapy with strain-based sulphonamide induced by strainsPlasmodium falciparum sensitive to this combination treatment and toxoplasmosis, including ocular infections, congenital infections and infections in immunodeficient patients.

1 tabl contains 25 mg of pyrimethamine.

Antiparasitic drug active against protozoaPlasmodium andToxoplasma. As a result of inhibiting the activity of dihydrofolate reductase, it inhibits selective transformation of folic acid in parasites, disturbing the synthesis of folinic acid, necessary for the formation of nucleic acids. Its affinity for the protozoan enzyme is much greater than that of the human enzyme. Pyrimethamine is quickly absorbed from the digestive tract. The maximum concentration in the blood occurs within 2-4 h. About 87% of the drug is combined with plasma proteins. It is excreted mainly in the form of metabolites, up to 30% excreted in the urine in unchanged form in a few weeks. T_0,5 is 85 h. The state of balance is achieved after 12-20 days of regular use.

Hypersensitivity to pyrimethamine. And trimester of pregnancy. Breastfeeding during toxoplasmosis treatment should be avoided.

During treatment in conditions related to folate deficiency, folate supplementation should be used. Folate supplementation is necessary during the treatment of toxoplasmosis. If signs of folate deficiency are observed, treatment should be discontinued and a high dose of Calcium folinate administered. Pyrimethamine may exacerbate folate deficiency in persons predisposed due to illness or poor nutrition (calcium folinate should be used as a folate supplement). In patients with megaloblastic anemia caused by folate deficiency, the benefits and risks of the preparation should be carefully considered. Particularly cautiously use in patients with a history of seizures (high-loading doses should be avoided). If sulfonamide is administered, adequate hydration should be provided to minimize the risk of crystalluria. Pyrimethamine is given with sulphonamides, therefore, when they are taken together, precautions should also be taken regarding the use of sulfonamides. In the case of prolonged treatment, due to the possible occurrence of active metabolites of pyrimethamine, the preparation should be used with particular caution in patients with impaired renal function. The preparation used in combination with sulphonamides is effective in the treatment of toxoplasmosis in patients with mild liver disease. In patients with impaired liver function, the dose should be individually adjusted.

During pregnancy, caution should be exercised when using pyrimethamine and provide folate supplementation. Special consideration should be given to the need to use the preparation for all pregnant women with suspected acquired toxoplasmosis and to consider the risks associated with the administration of the preparation and the risk of miscarriage or fetal defects caused by the infection. Combined use of pyrimethamine with sulfadiazine during pregnancy is indicated for confirmed placental or fetal infection and when the mother is at risk of serious consequences. Due to the risk of fetal damage resulting from the use of the product in early pregnancy, the use of combination therapy should be limited to the II and III trimester of pregnancy. For this reason, in the first trimester of pregnancy and in a situation where the diagnosis is not confirmed, an alternative therapy is recommended. Pyrimethamine crosses the placenta and into breast milk. Breast-feeding should be discontinued when high doses of pyrimethamine are administered in combination with sulfonamide for the treatment of toxoplasmosis.

Very common (≥1 / 10): anemia, headache, vomiting, nausea, diarrhea, rash. Common (≥1 / 100, <1/10): leukopenia, thrombocytopenia, dizziness. Uncommon (≥1 / 1000, <1/100): fever, impaired skin pigmentation.Very rare (<1 / 10,000): pancytopenia (deaths may occur in the absence of folate treatment), increase in blood phenylalanine (in neonates treated for congenital toxoplasmosis), vascular collapse (seen in patients treated with doses higher than recommended), insomnia (in patients treated with doses exceeding the recommended weekly doses), depression, pneumonia with cell and eosin infiltrates, arrhythmias, apathy, anxiety, convulsions, colic, mouth ulcers, dry mouth or throat, dermatitis, hematuria.

Orally. In the treatment of diarrhea or toxoplasmosis, pyrimethamine should not be used as monotherapy, it must be used in combination with sulfonamide, as indicated for its use.Dab. Adults and children over 14 years of age: once 50-75 mg in combination with 1000-1500 mg of sulfalenone or sufadoxin, higher doses should be used in adults weighing> 60 kg. Children under 4 years: 12.5 mg pyrimethamine (+ 250 mg sulfalenone or sufadoxine); children 4-8 years: 25 mg pyrimethamine (+ 500 mg sulfalenone or sufadoxine); children aged 9-14: 50 mg pyrimethamine (+ 1000 mg sulfalenone or sufadoxine).toxoplasmosis. The following dosage is only an indication for treatment, but the optimal dosage has not been clearly defined. Adults and children over 6 years: the loading dose is 100 mg per day, followed by maintenance therapy 25-50 mg per day (+ 2-4 g of sulfadiazine per day in divided doses). Children under 3 months with congenital toxoplasmosis: 6.25 mg / day every other day (+ sulfadiazine 100 mg / kg, ie maximum 750 mg / day or every other day); children 3-9 months: 6.25 mg per day (+ sulfadiazine 100 mg / kg, ie max. 1 g, daily in 4 doses); children 10 months-2 years: 1 mg / kg daily (+ sulfadiazine at a dose of 150 mg / kg, ie a maximum of 1.5 g); children 3-6 years: a loading dose of 2 mg / kg (maximum 50 mg) per day, followed by a maintenance therapy of 1 mg / kg. (maximum 25 mg) per day (+ sulfadiazine 150 mg / kg, ie maximum 2 g). Pyrimethamine treatment should be continued for 3-6 weeks. If indicated for further use, a break should be maintained for 2 weeks before the Next treatment. Patients receiving pyrimethamine should also receive folate supplementation during treatment of toxoplasmosis to reduce the risk of bone marrow suppression.
Doses lower than 25 mg should be prepared under the supervision of a pharmacist.