Risks of Treating a Child with Autism with Folinic Acid/Leucovorin

Safety Profile of Folinic Acid in Autism

The primary risks of treating a child with autism with folinic acid (leucovorin) include bone marrow suppression (neutropenia, anemia, and thrombocytopenia), which requires regular blood count monitoring, though this risk is generally low when used as a standalone treatment rather than in combination with pyrimethamine, as recommended by the Centers for Disease Control and Prevention (CDC) 1, 2
When used in the treatment of congenital toxoplasmosis (which requires higher doses and combination therapy), leucovorin is specifically administered to minimize the hematologic toxicity of pyrimethamine, according to the CDC 1, 2

Bone marrow suppression is the primary concern when leucovorin is used with pyrimethamine, but is less common when used alone, as noted by the CDC 1
Complete blood count monitoring should be performed weekly when used with daily pyrimethamine, as recommended by the CDC 1
Complete blood count monitoring should be performed monthly when used with less frequent pyrimethamine dosing, according to the CDC 2
Because of the long half-life of pyrimethamine when used in combination therapy, leucovorin should be continued for 1 week after pyrimethamine discontinuation, as recommended by the CDC 2

Consider baseline and periodic complete blood count monitoring, particularly if higher doses are used or if combined with other medications, as recommended by the CDC 2

Folinic acid treatment for ASD is considered complementary/alternative medicine and is not part of standard ASD treatment guidelines, according to the American Academy of Family Physicians 3, 4, 5
The U.S. Preventive Services Task Force notes that complementary and alternative medicine approaches for ASD have less robust evidence compared to behavioral interventions, as reported in the American Family Physician journal 6, 7