A 10-year-old child develops severe headache, neck stiffness, and migrating paresthesias after eating raw snails on a dare during a trip to Hawaii. A lumbar puncture shows pleocytosis with 20% eosinophils. While treatment is primarily supportive, what is the rationale for avoiding anthelmintic drugs in eosinophilic meningitis caused by Angiostrongylus cantonensis?