Pyrimethamine + sulfadiazine: 21-day course

Pyrimethamine: 0.5 to 2 mg/kg/day

Sulfadiazine: 50 to 100 mg/kg/day in two divided doses

Folic acid (leukovorin calcium): 2 to 20 mg (or 5 to 10 g bakers’ yeast) twice weekly during pyrimethamine treatment.

II. Prophylactic treatment during pregnancy

Treatment to be started as soon as prenatal diagnosis is made

Spiramnycin is 100 mg/kg/day in two divided doses, administered orally. Usually 2–4 g daily

Or

Spiramycin before the 20th week of pregnancy and thereafter pyrimethamine and sulfadiazine.

III. Congenital toxoplasmosis

Pyrimethamine: 2 mg/kg orally four times per day for 2 days, then 1 mg/kg per day for 6 months, then thrice weekly.

+ sulphadiazine: 100 mg/kg per day orally (two divided doses)

+ folinic acid: 5–10 mg orally thrice weekly

IV. Ocular toxoplasmosis

Pryimethamine 75 mg/day and sulfadiazine 2 grams daily, or Clindamycin, 300 mg orally, four times daily.

Coricosteroids: only if inflammation present

Prednisone or methylprednisone 1 to 2 mg/kg/ay in two divided doses.

Photocoagulation and cryotherapy around active retinochoroiditis lesion to kill T. gondii encysted at the periphery of the lesions.

V. AIDS patients

A. Acute toxoplasmic encephalitis

Primethamine 200 mg oral initially and then 75–100 mg orally four times daily

+ Sulfadiazine 1–2 grams oral, four times daily

Or

Pyrimethamine + clindamycin 60 mg orally or intravenously 6 hourly

Or

Pyrimethamine + dapsone 100 mg orally four times daily

Or

Pyrimethamine + azithromycin 1200–1500 mg orally four times daily.

Or

Pyrimethamine + clarithromycin 1 gram orally two times daily

B. Maintenance treatment

Doses of pyrimethamine and sulfadiazine reduced to half or less of those given for treating acute toxoplasmosis and the treatment continued for life

Folic acid should be given daily

C. Prophylactic treatment in AIDS patients with antibodies to T. gondii.

Trimethaprim–sulfamethoxazole, widely used for the prophylaxis and treatment of Pneumocystis carinii infections thought to reduce onset of toxoplasmic encephalitis