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    Prescription under medical supervision


    Therapeutic action

    • Sulfonamide antibacterial


    • Treatment and secondary prophylaxis of toxoplasmosis in immunodeficient patients, in combination with pyrimethamine

    Forms and strengths

    • 500 mg tablet

    Dosage and duration

    Treatment of toxoplasmosis

    • Adult: 2 g 2 to 3 times daily for 6 weeks minimum


    Secondary prophylaxis of toxoplasmosis

    • Adult: 1 to 1.5 g 2 times daily, as long as necessary

    Contra-indications, adverse effects, precautions

    • Do not administer to sulfonamide-allergic patients; patients with severe renal or hepatic impairment.
    • May cause:
      • gastrointestinal disturbances, renal disorders (crystalluria, etc.), photosensitivity, megaloblastic anaemia due to folic acid deficiency; haemolytic anaemia in patients with G6PD deficiency;
      • allergic reactions (fever, rash, etc.) sometimes severe (Lyell's and Stevens-Johnson syndromes, haematological disorders, etc.). In these cases, stop treatment immediately.
    • Adverse effects occur more frequently in patients with HIV infection.
    • Monitor blood count if possible.
    • Reduce the dose by half in patients with renal impairment.
    • Do not combine with methotrexate and phenytoin.
    • Administer calcium folinate systematically to prevent folic acid deficiency.
    • Drink a lot of liquid during treatment.
    • Pregnancy: no contra-indication. However, avoid using during the last month of pregnancy (risk of jaundice and haemolytic anaemia in the newborn infant).
    • Breast-feeding: avoid if preterm infant, jaundice, low-birth weight, infant under one month of age. If sulfadiazine is used, observe the infant for signs of jaundice.


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