What is the management approach for boric acid poisoning?

Management of Boric Acid Poisoning

For acute boric acid poisoning, immediately initiate aggressive fluid resuscitation with forced diuresis using furosemide, and strongly consider early hemodialysis for severe cases (serum boric acid >500 μg/mL) or when renal dysfunction develops, as this accelerates elimination approximately 4-fold compared to diuresis alone. 1, 2

Immediate Stabilization and Decontamination

• Perform gastric lavage if the patient presents within 1-2 hours of ingestion, followed by administration of activated charcoal and a cathartic (magnesium sulfate) 1
• Recognize that boric acid is cytotoxic to all cells and can cause vomiting, depression, diarrhea, metabolic acidosis, acute renal failure, seizures, and circulatory collapse 2, 3
• Monitor for the classic triad: gastrointestinal symptoms (vomiting, diarrhea), skin manifestations (erythema, exfoliation, desquamation), and CNS irritation 4

Critical pitfall: Early manifestations are nonspecific, and patients can deteriorate rapidly before characteristic skin findings appear 4

Forced Diuresis Protocol

• Administer 3-4 L of intravenous fluid with furosemide 100 mg over 4 hours to achieve aggressive diuresis 5
• This approach achieves elimination rates comparable to hemodialysis when initiated early 5
• Monitor serum and urinary boric acid concentrations at admission, 12 hours, and every 24 hours for 5 days 2
• Continue forced diuresis until serum boric acid levels fall below 30 μg/mL 2

Important caveat: Insufficient furosemide dosing can lead to persistent symptoms (fever, nausea, vomiting, headache) despite initial improvement 5

Hemodialysis Indications

Initiate hemodialysis when:

• Serum boric acid concentration exceeds 500 μg/mL 1, 2
• Signs of renal dysfunction develop 2
• Severe metabolic acidosis is present 2
• Patient shows signs of circulatory collapse or shock 3

Hemodialysis efficacy:

• Reduces boric acid half-life from 13.46 hours to 3.76 hours 1
• Increases total body clearance from 0.99 L/h to 3.53 L/h 1
• Achieves clearance of 235 mL/min with 70% extraction ratio 2
• Can remove approximately 5 g of boric acid per session 1

Alternative Extracorporeal Therapy

• Peritoneal dialysis is effective when hemodialysis is unavailable, particularly in infants and when instituted early 4
• Exchange transfusion may be considered in severe cases to rapidly decrease blood boron concentrations 3

Monitoring Parameters

Track these specific markers:

• Serum boric acid levels (target <30 μg/mL) 2
• Renal function (creatinine, BUN) to detect tubular necrosis 3
• Acid-base status for metabolic acidosis 2
• Neurological status for seizure activity 3
• Cardiovascular parameters for hypotension and shock 3

Duration of Treatment

• Continue intensive monitoring and treatment for at least 84-132 hours after admission 2, 5
• Patients typically show steady improvement over 64-84 hours with appropriate therapy 2, 5
• The patient was successfully discharged at 12 days post-admission without sequelae in one case series 1

Key Clinical Pearls

• Boric acid has a narrow therapeutic index and is often not recognized as highly poisonous, leading to delayed treatment 5
• Death results from circulatory collapse and shock if untreated 5, 3
• Early aggressive intervention with forced diuresis prevents severe renal damage and complications, even before renal dysfunction becomes apparent 2
• Complete removal of boric acid from hospitals and pharmacies has been recommended due to its doubtful therapeutic value and significant toxicity 4