How is CNS toxoplasmosis treated in patients with HIV infection?

Updated: Jul 11, 2017
  • Author: Gulshan Uppal, MD; Chief Editor: Niranjan N Singh, MBBS, MD, DM, FAHS, FAANEM  more...
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In patients in whom brain imaging shows multiple lesions, whether serologic results are negative or positive, antitoxoplasmosis therapy should be initiated. In cases of impending herniation, an open biopsy with decompression is indicated. Corticosteroid treatment may be warranted in cases of impending brain herniation. However, their use may complicate the interpretation of a response to antitoxoplasmosis therapy.

Recently in 100 patients treated with pyrimethamine-sulfadiazine, the use of adjunctive steroids to treat cerebral edema associated with focal lesions appeared safe but was not associated with better neurologic outcomes. [9]

Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting. Antibiotic combinations usually are recommended to circumvent resistance from bacterial subpopulations (which may be resistant to one of the antibiotic components) and to provide additive or synergistic effect.

Standard therapy consists of pyrimethamine, sulfadiazine, and folinic acid in combination. Trimethoprim-sulfamethoxazole (TMP-SMZ) can be used as an alternative regimen. [10] A Cochrane database review found no significant differences between standard therapy and TMP-SMZ. Clindamycin can be used in patients allergic to sulfa drugs. Effective antiretroviral therapy is equally important. [11, 10, 12, 13]

Suggested dosing:

  • Sulfadiazine: 1000 mg 4 times daily among patients 60 kg.
  • Pyrimethamine: 200 mg loading dose followed by 50 mg daily among patients60 kg.
  • Leucovorin should be administered to prevent pyrimethamine induced hematologic toxicity. Dose can be 10-25 mg daily. 

With antibiotic therapy, 74% of patients improve by day 7, and 91% improve by day 14. Imaging studies are performed every 4-6 weeks until complete resolution of the lesion or stabilization after partial resolution.

Primary therapy is given for 6 weeks, followed by long-term suppressive therapy at reduced doses, with the duration determined by response to highly active antiretroviral therapy (HAART). The long-term suppressive therapy can be discontinued in patients with persistent elevation of CD4+ counts greater than 200 cells/µL and resolution of lesions on MRI.

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