From the FDA Drug Label
Urinalysis and urine sediment, renal and hepatic function and serum electrolyte levels should be checked before each course of therapy and then be monitored daily during therapy in severe cases, and in less serious cases after the second and fifth day of therapy. Elevated erythrocyte protoporphyrin levels (> 35 mcg/dl of whole blood) indicate the need to perform a venous blood lead determination. An elevation of urinary coproporphyrin (adults: > 250 mcg/day; pediatric patients under 80 lbs: > 75 mcg/day) and elevation of urinary delta aminolevulinic acid (ALA) (adults: > 4 mg/day; pediatric patients: > 3 mg/m2/day) are associated with blood lead levels > 40 mcg/dl
Recommended blood tests if lead poisoning is suspected:
- Venous blood lead determination
- Erythrocyte protoporphyrin levels Other tests that may be useful include:
- Urinalysis and urine sediment
- Renal and hepatic function tests
- Serum electrolyte levels
- Urinary coproporphyrin
- Urinary delta aminolevulinic acid (ALA) 1
From the Research
If lead poisoning is suspected, several additional blood tests are recommended beyond the initial blood lead level test, including a complete blood count (CBC), liver function tests, kidney function tests, iron studies, zinc protoporphyrin (ZPP) test, hemoglobin electrophoresis, and vitamin D levels, as supported by recent studies such as 2 and 3. When suspecting lead poisoning, it is crucial to conduct a comprehensive set of blood tests to assess the extent of the poisoning and its impact on various bodily functions.
- A complete blood count (CBC) should be performed to check for anemia and basophilic stippling of red blood cells, which can occur with lead toxicity.
- Liver function tests and kidney function tests (including BUN and creatinine) are important to assess organ damage from lead exposure, as indicated by studies like 4 that show significant associations between blood lead levels and renal, liver, and hematologic impairments.
- Iron studies, including ferritin, iron, and total iron-binding capacity, help evaluate iron status since iron deficiency can increase lead absorption.
- A zinc protoporphyrin (ZPP) test is useful as it becomes elevated with chronic lead exposure.
- Hemoglobin electrophoresis may be needed to rule out other causes of anemia.
- Vitamin D levels should be checked as deficiency can increase lead absorption. In children, additional tests to assess cognitive and developmental impacts may be warranted, considering the potential for lead to affect brain development, as noted in 5. These comprehensive tests help determine the severity of poisoning, identify complications, guide treatment decisions, and establish baseline values for monitoring recovery during chelation therapy or other interventions, aligning with the findings of studies like 2 and 3 that highlight the importance of monitoring kidney function in the context of lead exposure.