Ocular Toxoplasmosis
Guideline for Ophthalmology use only.
- Always speak to Micro/ID on suspicion of ocular toxoplasmosis.
- In cases of newly acquired toxoplasmosis during pregnancy – inform uveitis consultant and obstetrician consultant. The following regimens are not recommended in pregnancy. Consult Micro/ID for alternatives.
- In immunocompromised patients (always suspect in large, multiple and bilateral lesions with or without scars) inform the treating physician and arrange brain imaging to rule out CNS involvement (56% risk of cerebral involvement in patients with HIV). Treat as per protocol for sight threatening lesions. Inform uveitis consultant.
- Do not use systemic corticosteroids without antimicrobial coverage because of the potential for severe panophthalmitis.
- Do not use long acting periocular and/or intraocular steroids (such as triamcinolone acetonide) because of the potential for severe panophthalmitis.
Preferred
pyrimethamine* 100mg po STAT, then 25mg po od
PLUS
Sulfadiazine 3g po STAT, then 1g po tds
PLUS
Folinic acid 15mg po od
PLUS
Prednisolone 0.5mg/kg-1mg/kg po od (max dose 60mg per day, slow taper) to commence after 48 hours of antibiotic therapy.
*Pyrimethamine can cause myelosuppression: repeat FBC every 2 weeks during treatment.
Alternatives
First line
co-trimoxazole 960mg po bd
PLUS Prednisolone 0.5mg/kg-1mg/kg po od (max dose 60mg per day, slow taper) to commence after 48 hours of antibiotic therapy.
Second line
azithromycin 500mg po STAT, then azithromycin 250mg po od for 5 weeks.
PLUS Prednisolone 0.5mg/kg-1mg/kg po od (max dose 60mg per day, slow taper) to commence after 48 hours of antibiotic therapy.
If patient is not responding to alternative treatment options, speak to Micro/ID and Ophthalmology.
Toxoplasmosis prophylaxis
Need for prophylaxis to be decided by consultant ophthalmologist and Micro/ID
Primary prophylaxis
co-trimoxazole 960mg po od three times per week or 480mg po od
If co-trimoxazole is not suitable, contact Micro/ID for alternative options.