Treating Toxoplasma gondii Encephalitis

Preferred Regimen (AI):

• Pyrimethamine 200 mg PO once, followed by dose based on body weight:
  • Body weight ≤60 kg: pyrimethamine 50 mg PO daily + sulfadiazine 1000 mg PO q6h + leucovorin 10–25 mg PO daily (can increase to 50 mg daily or BID)
  • Body weight >60 kg: pyrimethamine 75 mg PO daily + sulfadiazine 1500 mg PO q6h + leucovorin 10–25 mg PO daily (can increase to 50 mg daily or BID)

Alternative Regimens:

• Pyrimethamine (leucovorin) plus clindamycin 600 mg IV or PO q6h (AI); preferred alternative for patients intolerant of sulfadiazine or who do not respond to pyrimethamineb-sulfadiazine; must add additional agent for PCP prophylaxis, or
• TMP-SMX (TMP 5 mg/kg and SMX 25 mg/kg) (IV or PO) BID = 2 x 1920mg gewoonlijk (BI)

Total Duration for Treating Acute Infection:

• At least 6 weeks (BII); longer duration if clinical or radiologic disease is extensive or response is incomplete at 6 weeks
• After completion of the acute therapy, all patients should be continued on chronic maintenance therapy as outlined below

Chronic Maintenance Therapy for Toxoplasma gondii Encephalitis

Preferred Regimen:

• Pyrimethamine 25–50 mg PO daily + sulfadiazine 2000–4000 mg PO daily (in 2 to 4 divided doses) + leucovorin 10–25 mg PO daily (AI)

Alternative Regimen:

• Clindamycin 600 mg PO q8h + (pyrimethamine 25–50 mg + leucovorin 10–25 mg) PO daily (BI); must add additional agent to prevent PCP (AII), or
• TMP-SMX 960mg 1 tablet daily (BII)

Discontinuing Chronic Maintenance Therapy:

• Successfully completed initial therapy, remain asymptomatic of signs and symptoms of TE, and CD4 count >200 cells/mm3 for >6 months in response to ART (BI)

Criteria for Restarting Secondary Prophylaxis/Chronic Maintenance

• CD4 count <200 cells/mm3 (AIII)

Other Considerations:

• Adjunctive corticosteroids (e.g., dexamethasone) should only be administered when clinically indicated to treat a mass effect associated with focal lesions or associated edema (BIII); discontinue as soon as clinically feasible, because it impedes proper evaluation of antibiotic response.
• Anticonvulsants should be administered to patients with a history of seizures (AIII) and continued through at least through the period of acute treatment; anticonvulsants should not be used as seizure prophylaxis (BIII).