Toxicology

efficacy.

The use of a cathartic (e.g., sorbitol) in combination with activated charcoal is not recommended.

If significant nausea occurs, it is recommended to administer an antiemetic. When choosing an

antiemetic, potential drug and symptom interactions should be considered as well.

Complications include aspiration, accidental administration into the lung, emesis, constipation, and

gastric obstruction.

Contraindications include an unconscious state or an inability to otherwise protect the airway without

endotracheal intubation, ileus or intestinal obstruction, late presentation (more than 2 hours), and recent

GI surgery.

Multidose activated charcoal is a method described to enhance the elimination of certain toxins. It is not

more effective in reducing morbidity or mortality than single-dose charcoal, but it may be administered

to enhance elimination in life-threatening ingestions caused by medications that undergo significant

enterohepatic recirculation with active enterohepatic metabolites (J Toxicol Clin Toxicol 1999;37:731-

51).

Whole Bowel Irrigation

Whole bowel irrigation is a strategy for cleansing the bowel to remove potential toxins by administering

an osmotic polyethylene glycol solution.

medications with long half-lives, sustained-release dosage forms, or enteric-coated formulations.

Specifically useful for certain toxic substances not adsorbed by activated charcoal (e.g., lithium and

iron). May also be beneficial for iron overdoses and for “packers” of illicit substances.

Concurrent administration of activated charcoal and whole bowel irrigation may decrease the efficacy

of charcoal.

Complications of the polyethylene glycol electrolyte solutions include anaphylaxis, angioedema of the

lips, aspiration, Mallory-Weiss tear, and esophageal perforation.

Contraindications include bowel obstruction, perforation, ileus, and use in patients with recent bowel

surgery. A kidney-ureter-bladder radiograph may be used to rule out these contraindications.

Urine alkalinization is a strategy to improve the elimination of toxins by increasing the urine pH to

levels of 7.5 or greater via administration of sodium bicarbonate or sodium acetate (J Toxicol Clin

Toxicol 2004;42:1-26).

and other weak acids with intrinsic urinary clearance.

Contraindications include acute and chronic renal failure and preexisting heart failure owing to the

volume of fluid required for this treatment strategy.

Complications include hypokalemia, hypernatremia, hypocalcemia, cerebral vasoconstriction, and

coronary vasoconstriction.

To deploy urine alkalinization therapy, it is recommended to check baseline blood chemistries, electrolyte

values, and an arterial blood gas, as well as to correct any fluid or electrolyte deficits (especially potassium

because alkalemia will push potassium intracellularly). Hypokalemia will make it impossible to get the

urine alkaline because of the K+-H+ exchange in the kidneys, which will excrete H+ into urine if K+ is

low.

Guideline-recommended monitoring includes urine pH every 15–30 minutes (every 30–60 minutes

is more accepted in clinical practice) until the goal pH level of 7.5–8.5 is achieved, followed by every

hour; serum potassium concentrations, central venous pressure, and arterial blood gases should be

measured hourly.