When to chelate for lead toxicity?

Indication: 


Chelation therapy should be considered for lead toxicity if lead concentrations are higher than 44.0 mcg/dL. For levels between 10 and 44 frequent monitoring is recommended.

Drugs:


Succimer is the drug of choice for children whose blood lead concentrations are 45.0 to 100.0 mcg/dL . At values higher than 69.0 mcg/dL, a second drug, Calcium Disodium EDTA (Not to be confused with Sodium EDTA), is added. The first dose always is succimer, followed 4 hours later by EDTA, because children who present with lead encephalopathy may deteriorate when treated with EDTA alone.

Blood lead levels fall rapidly after chelation, but rebound within weeks, even if there is no further exposure to lead, due to release of lead from bone stores. These levels usually are not high enough to indicate chelation but if they do a second round of chelation may be needed.