Dimercaprol

BAL

What it isDithiol chelator; arsenic, mercury, gold and lead poisoning.

Why this oneIt is the chelator for arsenic and inorganic mercury, where oral agents fail.

What limits itPainful intramuscular injection in peanut oil, and it redistributes some metals to the brain. Hypertension and fever.

FDA label

FDA dosing	Population	Start
Mild arsenic or gold poisoning	All	2.5 mg/kg IM QID ×2 days, then BID on day 3, then QD ×10 days
Severe arsenic or gold poisoning	All	3 mg/kg IM q4h ×2 days, QID on day 3, then BID ×10 days
Mercury poisoning	All	5 mg/kg IM initially, then 2.5 mg/kg QD–BID ×10 days
Acute lead encephalopathy	All	4 mg/kg IM first dose alone, then q4h with edetate calcium disodium at a separate site (3 mg/kg after first dose if less severe)

Renal Discontinue or use only with extreme caution if acute renal insufficiency develops during therapy.

Hepatic Contraindicated in most instances of hepatic insufficiency (exception: post-arsenical jaundice).

By deep intramuscular injection only
Begin injections at the earliest possible moment; use adequate amounts at frequent intervals
Inspect visually for particulate matter and discoloration before administration
Use with other supportive measures
Treatment maintained for 2 to 7 days for acute lead encephalopathy depending on clinical response

Hepatic insufficiency, in most instances (exception: post-arsenical jaundice)
Discontinue or use with extreme caution if acute renal insufficiency develops during therapy

Pregnancy Pregnancy Category C; use only if clearly needed.

Lactation Unknown whether excreted in human milk; exercise caution in nursing women.

NO BOXED WARNINGS

Principal riskPainful injection; it can redistribute metal to the brain

Direct muscarinic antagonism0 / 4