DIMERCAPROL
(dye-mer-kap'role)
BAL in Oil, British Anti-Lewisite
Classifications: chelating agent; antidote
Pregnancy Category: D

Availability

100 mg/mL injection

Actions

Dithiol compound that combines with ions of various heavy metals to form relatively stable, nontoxic, soluble complexes called chelates, which can be excreted; inhibition of enzymes by toxic metals is thus prevented. May also reactivate affected enzymes but is most effective when administered prior to enzyme damage.

Therapeutic Effects

Neutralizes the effects of various heavy metals.

Uses

Acute poisoning by arsenic, gold, and mercury; as adjunct to edetate calcium disodium (EDTA) in treatment of lead encephalopathy.

Unlabeled Uses

Chromium dermatitis; ocular and dermatologic manifestations of arsenic poisoning, as adjunct to penicillamine to increase rate of copper excretion in Wilson's disease, and for poisoning with antimony, bismuth, chromium, copper, nickel, tungsten, zinc.

Contraindications

Hepatic insufficiency (with exception of post-arsenical jaundice); severe renal insufficiency; poisoning due to cadmium, iron, selenium, or uranium; pregnancy (category D), lactation.

Cautious Use

Hypertension, patients with G6PD deficiency.

Route & Dosage

Arsenic or Gold Poisoning
Adult/Child: IM 2.5–3 mg/kg q4h for first 2 d, then q.i.d. on third day, then b.i.d. for 10 d

Mercury Poisoning
Adult/Child: IM 5 mg/kg initially, followed by 2.5 mg/kg 1–2 times/d for 10 d

Acute Lead Encephalopathy
Adult/Child: IM 4 mg/kg initially, then 3–4 mg/kg q4h with EDTA for 2–7 d depending on response

Administration

Intramuscular

Adverse Effects (1%)

CNS: Headache, anxiety, muscle pain or weakness, restlessness, paresthesias, tremors, convulsions, shock. CV: Elevated BP, tachycardia. Special Senses: Rhinorrhea; burning sensation, feeling of pain and constriction in throat. GI: Nausea, vomiting; burning sensation in lips and mouth, halitosis, salivation; abdominal pain, metabolic acidosis. Urogenital: Burning sensation in penis, renal damage. Other: Pains in chest or hands, pain and sterile abscess at injection site, sweating, reduction in polymorphonuclear leukocytes, dental pain.

Diagnostic Test Interference

I131 thyroid uptake values may be decreased if test is done during or immediately following dimercaprol therapy.

Interactions

Drug: Iron, cadmium, selenium, uranium form toxic complexes with dimercaprol.

Pharmacokinetics

Peak: 30–60 min. Distribution: Distributed mainly in intracellular spaces, including brain; highest concentrations in liver and kidneys. Elimination: Completely excreted in urine and bile within 4 h. Half-Life: Short.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education


Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug