The Poison Review

DIMERCAPTOSUCCINIC ACID (SUCCIMER; DMSA) IN INORGANIC LEAD POISONGING Bradberry S, Vale A. Clin Toxicol 47:617-631.

Abstract

This is an ambitious paper and I really hoped to find it more helpful than I actually did.  The authors performed a literature review, considering a whopping 912 papers (and reviewing in detail 50 papers) concerning the treatment of inorganic led poisoning with succimer.  Their conclusion: “(Oral) DMSA 30 mg/kg/day achieves good lead excretion, is well-tolerated, and can be administered orally . . . it may now be considered as an alternative antidote to sodium calcium edetate in patients poisoned with lead”. This is not surprising — many experts in the United States recommend succimer as first-line treatment in a lead poisoned patient with mild or absent symptoms.  However, most experts would start with BAL and EDTA in a patient with lead encephalopathy or levels > 70 cg/dL, settings in which the use of succimer has not been well studied.

Some take-home lessons from this study:

1)  Metabolism of DMSA appears to take place in the kidney, where the actual binding of lead by a DMSA metabolite seems to take place.

2)   Adverse effects of DMSA include mild hepatic transaminate elevations and mucocutaneous eruptions that may be severe.

3)  Excretion of lead is usually maximal on the first day of chelation with DMSA.