Clinical management of boric acid ingestion: pharmacokinetic assessment of efficacy of hemodialysis for treatment of acute boric acid poisoning.
Seven hours after suicidal ingestion of about 21 g of boric acid, a 26-year-old female admitted to our hospital in a state of slightly impaired consciousness, with frequent vomiting, shivering, fever and skin flush. Immediately, gastric lavage, followed by administration of activated charcoal and laxative (MgSO4), was performed. In order to ensure her urination, fluid infusion therapy was conducted with the aid of diuretics (furosemide). Since the serum concentrations of boric acid was very high, hemodialysis was carried out twice during the first 39 h. She responded well to the above mentioned treatment and was discharged 12 d post-admission without any sequelae. The concentrations of boric acid in serum and urine were measured in appropriate intervals with our modified Miyamoto's method, and the pharmacokinetics of boric acid were analyzed. The concentration of boric acid in serum and urine at the beginning of treatment was 465 micrograms/ml and 3.40 mg/ml, respectively. The half-life of boric acid in serum was 13.46 h, whereas it was shortened to 3.76 h during hemodialysis. The total body clearance was 0.99 l/h, while it increased to 3.53 l/h by hemodialysis. The additional removal of boric acid by hemodialysis was estimated to be about 5 g. It was concluded that the hemodialysis was very useful in the treatment of boric acid poisoning, because it accelerated the elimination of boric acid about four times faster than with conventional treatment.