Prospective evaluation of gastric emptying in the self-poisoned patient

Tricyclic antidepressant overdose: a review

Overdoses of tricyclic antidepressants are among the commonest causes of drug poisoning seen in accident and emergency departments. This review discusses the pharmacokinetics, clinical presentation and treatment of tricyclic overdose.

Esophageal laceration and charcoal mediastinum complicating gastric lavage

A 19-year-old woman underwent multiple attempts at orogastric lavage before success 5 h after ingesting approximately 24 grams of ibuprofen in a suicide attempt. Activated charcoal was administered via the lavage tube. She vomited charcoal shortly after administration and began experiencing difficulty breathing and an increase in the pitch of her voice. A chest X-ray study showed a widened mediastinum, pneumopericardium, and subcutaneous emphysema consistent with esophageal perforation that was confirmed by computed tomography scan. Surgical exploration revealed a tear in the proximal posterior esophagus with charcoal in the posterior mediastinum. She remained intubated for 7 days and was discharged 14 days after admission. This is a report of esophageal perforation with activated charcoal contamination of the mediastinum after gastric lavage. The risks and benefits of this procedure should be carefully considered in each patient prior to its use. Awake patients should be cooperative with the procedure to minimize any risk of trauma to the oropharynx or esophagus.

Indications for, techniques of, complications of, and efficacy of gastric lavage in the treatment of the poisoned child

Gastrointestinal decontamination is central to the care of poisoned patients, and gastric lavage is one common method for gastrointestinal decontamination. Gastric lavage in pediatric patients should be limited to children who present shortly after a potentially life-threatening ingestion. The routine use of gastric lavage has recently been questioned because of limited outcome data and increased morbidity. If gastric lavage is deemed necessary, proper positioning of the patient and strict attention to appropriate technique are essential to avert complications.

Activated charcoal as the sole intervention for treatment after childhood poisoning

Childhood poisonings account for approximately two thirds of all human toxic exposures reported annually to the American Association of Poison Control Centers. Activated charcoal (AC) is the mainstay of decontamination in the emergency department setting. This review focuses on six concepts: 1) description of AC and its method of action, 2) evolution of AC in the gastrointestinal decontamination process, 3) prehospital use of AC, 4) superactivated charcoal, 5) multiple-dose AC, and 6) complications of AC administration. The most recent evolving trends in decontamination of the pediatric patient include trends toward earlier decontamination, either in the home or by paramedics in the field. The newer, "super" activated charcoals, with their greater surface area, may improve compliance of oral administration of AC. Finally, guidelines have been set to limit use of multiple-dose activated charcoal regimens to certain pharmaceuticals only, as well as discouraging cathartic use with charcoal dosing.

Past, present, and future role of ipecac syrup

Historically, ipecac syrup has played a principal role in the management of acute poisonings and overdoses. Presently, its role largely has been relegated to prompt decontamination of acute childhood poisonings for which emesis is not contraindicated. However, even this specific and limited role has undergone rigorous re-evaluation, and many toxicologists have discouraged against its use in any circumstance. This article reviews the history, scientific literature, and public health implications of ipecac syrup that support its present clinical application.

Activated charcoal reduces the need for N-acetylcysteine treatment after acetaminophen (paracetamol) overdose

BACKGROUND

The evidence for efficacy of gastric lavage and activated charcoal for gastrointestinal decontamination in poisoning has relied entirely on volunteer studies and/or pharmacokinetic studies and evidence for any clinical benefits or resource savings is lacking.

AIM OF STUDY

To investigate the value of gastrointestinal decontamination using gastric lavage and/or activated charcoal in acetaminophen (paracetamol) poisoning.

PATIENTS AND METHODS

We analyzed a series of 981 consecutive acetaminophen poisonings. These patients were treated with gastric lavage and activated charcoal, activated charcoal alone, or no gastrointestinal decontamination. The decision as to which treatment was received was determined by patient cooperation, the treating physician, coingested drugs, and time to presentation after the overdose.

RESULTS

Of 981 patients admitted over 10 years, 10% (100) had serum concentrations of acetaminophen that indicated a probable or high risk of hepatotoxicity. The risk of toxic concentrations for patients ingesting less than 10 g of acetaminophen was very low. In patients presenting within 24 hours, who had ingested 10 g or more, those who had been given activated charcoal were significantly less likely to have probable or high risk concentrations (Odds ratio 0.36, 95% CI 0.23-0.58, p < 0.0001). Gastric lavage, in addition to activated charcoal, did not further decrease the risk (Odds ratio 1.12, 95% CI 0.57-2.20, p = 0.86).

CONCLUSIONS

Toxic concentrations of serum acetaminophen (paracetamol) are uncommon in patients ingesting less than 10 g. In those ingesting more, activated charcoal appears to reduce the number of patients who achieve toxic acetaminophen concentrations and thus may reduce the need for treatment and hospital stay.

Recent advancements in pediatric toxicology

Ingestion of potentially poisonous agents is a common reason for children to present to an emergency department. The clinician must decide whether gastrointestinal decontamination is indicated for these patients. The controversy over the type of gastrointestinal decontamination is resolving and recent recommendations are reviewed. Also two new antidotes, fomepizole for toxic alcohols and octreotide for sulfonylureas, are reviewed.

Incidence of aspiration pneumonia in intubated patients receiving activated charcoal

Several case reports and animal studies raise concerns over the risk of aspiration pneumonia when administering activated charcoal (AC) to intubated patients. Therefore, we sought to determine the incidence of aspiration pneumonia in intubated overdose patients who then received AC. We conducted a retrospective review from January 1994 to April 1997 of intubated patients who then received AC. Patients were transferred to, or primarily treated at, an 843-bed tertiary medical center with an annual emergency department volume of 100,000 patients. Objective evidence of infiltrate on chest radiograph during initial 48 h of hospitalization was used to determine the incidence of aspiration pneumonia. Patients with known preexisting pneumonia or with administration of AC before intubation were excluded. There were 64 patients identified. Fourteen were excluded for clinical aspiration before intubation, receiving activated charcoal before intubation, or abnormal immediate post-intubation chest radiographs. The remaining 50 patients, ages 1-64 years, 33% male, overdosing on a large variety of substances, required acute intubation and then received AC. Only two patients of these 50 (4%) with initial negative radiographs developed a new infiltrate after intubation and AC. Administration of AC to intubated overdose patients is associated with a low incidence of aspiration pneumonia.

Position statement: single-dose activated charcoal. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists

In preparing this Position Statement, all relevant scientific literature was identified and reviewed critically by acknowledged experts using agreed criteria. Well-conducted clinical and experimental studies were given precedence over anecdotal case reports and abstracts were not usually considered. A draft Position Statement was then produced and subjected to detailed peer review by an international group of clinical toxicologists chosen by the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists. The Position Statement went through multiple drafts before being approved by the boards of the two societies and being endorsed by other societies. The Position Statement includes a summary statement for ease of use and is supported by detailed documentation which describes the scientific evidence on which the Statement is based. Single-dose activated charcoal should not be administered routinely in the management of poisoned patients. Based on volunteer studies, the effectiveness of activated charcoal decreases with time; the greatest benefit is within 1 hour of ingestion. The administration of activated charcoal may be considered if a patient has ingested a potentially toxic amount of a poison (which is known to be adsorbed to charcoal) up to 1 hour previously; there are insufficient data to support or exclude its use after 1 hour of ingestion. There is no evidence that the administration of activated charcoal improves clinical outcome. Unless a patient has an intact or protected airway, the administration of charcoal is contraindicated.

Position statement: gastric lavage. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists

In preparing this Position Statement, all relevant scientific literature was identified and reviewed critically by acknowledged experts using agreed criteria. Well-conducted clinical and experimental studies were given precedence over anecdotal case reports and abstracts were not usually considered. A draft Position Statement was then produced and subjected to detailed peer review by an international group of clinical toxicologists chosen by the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists. The Position Statement went through multiple drafts before being approved by the boards of the two societies and being endorsed by other societies. The Position Statement includes a summary statement for ease of use and is supported by detailed documentation which describes the scientific evidence on which the Statement is based. Gastric lavage should not be employed routinely in the management of poisoned patients. In experimental studies, the amount of marker removed by gastric lavage was highly variable and diminished with time. There is no certain evidence that its use improves clinical outcome and it may cause significant morbidity. Gastric lavage should not be considered unless a patient has ingested a potentially life-threatening amount of a poison and the procedure can be undertaken within 60 minutes of ingestion. Even then, clinical benefit has not been confirmed in controlled studies. Unless a patient is intubated, gastric lavage is contraindicated if airway protective reflexes are lost. It is also contraindicated if a hydrocarbon with high aspiration potential or corrosive substance has been ingested.

Position statement: ipecac syrup. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists

In preparing this Position Statement, all relevant scientific literature was identified and reviewed critically by acknowledged experts using agreed criteria. Well-conducted clinical and experimental studies were given precedence over anecdotal case reports and abstracts were not usually considered. A draft Position Statement was then produced and subjected to detailed peer review by an international group of clinical toxicologists chosen by the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists. The Position Statement went through multiple drafts before being approved by the boards of the two societies and being endorsed by other societies. The Position Statement includes a summary statement for ease of use and is supported by detailed documentation which describes the scientific evidence on which the Statement is based. Syrup of ipecac should not be administered routinely in the management of poisoned patients. In experimental studies the amount of marker removed by ipecac was highly variable and diminished with time. There is no evidence from clinical studies that ipecac improves the outcome of poisoned patients and its routine administration in the emergency department should be abandoned. There are insufficient data to support or exclude ipecac administration soon after poison ingestion. Ipecac may delay the administration or reduce the effectiveness of activated charcoal, oral antidotes, and whole bowel irrigation. Ipecac should not be administered to a patient who has a decreased level or impending loss of consciousness or who has ingested a corrosive substance or hydrocarbon with high aspiration potential.

Prevention of gastrointestinal iron absorption by chelation from an orally administered premixed deferoxamine/charcoal slurry

STUDY OBJECTIVE

To investigate the effect of an orally administered premixed slurry of deferoxamine mesylate (DFO) and activated charcoal (AC) on the gastrointestinal (GI) absorption of ferrous sulfate under physiologic conditions.

METHODS

This was a prospective, crossover, controlled human volunteer study. Participants were healthy adult subjects aged 25 to 38 years. Volunteers ingested either 5 mg/kg ferrous sulfate alone, 5 mg/kg ferrous sulfate added to 25 g of 20% (weight/ volume) AC, or 5 mg/kg ferrous sulfate added to a premixed slurry consisting of 8 g of DFO and 25 g of 20% (weight/volume) AC. The same group of volunteers was used in each limb of the study. Serum iron concentrations were measured at baseline and at 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours after ingestion for all subjects. Urinary iron was determined over the first 12 hours after ingestion for each limb. The maximum iron concentration (Cmax), the time to maximum iron concentration (Tmax), and the area under the curve (AUC) were compared for all three limbs.

RESULTS

The AUC (P = .042) and Cmax (P = .017) were significantly lower in all subjects in the DFO/AC limb compared with the two control limbs. There was no significant difference in the Tmax iron concentration (P = .77). In the ferrous sulfate control limb, female volunteers had a significantly higher mean Cmax (P = .008) and AUC (P = .014) than males. Iron was undetectable in all baseline and 12-hour urine collections.

CONCLUSION

In this model, a premixed 1:3 (weight/weight) DFO/ AC slurry reduced the GI absorption of ferrous sulfate in adult volunteers under physiologic conditions.

Gastrointestinal decontamination after poisoning. Where is the science?

The approach to the use of gastrointestinal decontamination procedures in the treatment of ingested toxins has changed in recent years. Many toxicologists and physicians have taken strong positions either for or against the use of emesis, gastric lavage, activated charcoal, or other procedures. What is the scientific basis for these positions? This article reviews and comments on the published studies comparing the effectiveness of these widely used procedures.

Poisoning and drug overdose

Poisoning is a common cause for intensive care unit admission for both children and adults, and most poisoning victims are effectively treated using standard decontamination measures and supportive care. For a small number of poisons, acceleration of toxin removal with hemodialysis or hemofiltration is indicated. Similarly, specific antidotes are indicated in a few selected circumstances. Rarely, patients may benefit from more aggressive supportive techniques such as cardiopulmonary bypass.

Gastrointestinal decontamination in the emergency department

Pediatric poisoning is a problem commonly encountered in the emergency department. After stabilization of airway, breathing, and circulation, one of the goals of treatment is decontamination in order to limit poison absorption and the resulting systemic toxicity. Decontamination modalities include gastric emptying (ipecac and gastric lavage), inhibiting absorption (activated charcoal), and catharsis (sorbital, magnesium citrate, and whole bowel irrigation). Each modality is discussed. Choice of modality by the practitioner must be individualized to each patient's situation.

Pearls, pitfalls, and updates in toxicology

Pearls and pitfalls learned from our practical experiences caring for poisoned patients are presented. Clinical pearls include the following: using diagnostic tests to detect end-organ toxicity, applying physiologic principles to the management of hemodynamically unstable poisoned patients, and dealing with psychologic injuries from hazardous materials incidents. Recognizing serious complications from poisoning and adverse drug effects, including the serotonin syndrome, are offered as pitfalls. Pharmaceutical companies are rapidly developing and marketing new therapies. Therefore, updates on the evolving role of NAC as an antidote for acetaminophen poisoning, new psychotropic medications, and new antidotes were included in this article. These pearls, pitfalls, and updates are intended to provide practical information that is readily applicable to the clinical practice of emergency medicine.

A comparison of three gastric lavage methods using the radionuclide gastric emptying study

To determine the percentage of liquid gastric contents experimentally removable by available orogastric lavage systems, five healthy young volunteers were asked to ingest 1 mCi of liquid technicium-99m diethylenetriaminepentaacetic acid (Tc99m-DTPA) mixed with 50 ml tap water. Five minutes afterwards, the radionuclide was lavaged using one of three different techniques-a single syringe method, a closed gravity drainage system, and a closed double syringe method--while continuous radioisotope camera images were taken. Control images, with no lavage performed, were also taken. All of the orogastric lavage methods removed a mean of between 80% and 85% of the stomach contents. The double syringe method was the quickest, while the single syringe method was least tolerated. When compared with control, none of the lavage techniques pushed gastric contents into the duodenum. Thus, in terms of amount of liquid gastric contents removed, there was no one method that removed more than the others. Caution should be exercised in assuming that 80-85% of a liquid gastric ingestion can be removed by lavage in the uncontrolled clinical setting. The use of any orogastric lavage for ingestion evacuation should be undertaken knowing that it is a morbid procedure and usually not necessary.

Gastric emptying in acute overdose: a prospective randomised controlled trial

OBJECTIVE

To test the hypothesis that administration of activated charcoal is as efficacious and safe as the combination regimen of gastric emptying plus charcoal in adults after acute oral overdose.

DESIGN

Prospective randomised controlled trial, with subjects presenting on odd-numbered dates allocated to the emptied group (E), and those on even-numbered dates to the not-emptied group (NE).

SETTING

Princess Alexandra Hospital, Brisbane (a tertiary referral hospital), which serves an adult urban community, between 4 January 1988 and 11 June 1990.

SUBJECTS

Consecutive patients (13 years or older) who presented to the Emergency Department after ingesting an overdose of one or more compounds able to be adsorbed by activated charcoal.

INTERVENTIONS

All patients received charcoal by the oral or nasogastric route. Those in the E group also had gastric emptying by ipecac-induced emesis or gastric lavage.

OUTCOME MEASURES

Clinical course during the first six hours after treatment began, length of hospital stay, complications.

RESULTS

876 patients were eligible for the study. There were no significant differences between the E and NE groups in age and sex distribution, severity of the overdose or other characteristics, except the mean interval between presentation and administration of charcoal (91 min [SD, 52] for E group and 55 [SD, 41] for NE group; P = 0.0001). There were no significant differences between the E and NE groups in outcome, even when the groups were stratified for severity of the overdose or into subgroups that presented sooner or later than one hour after ingestion.

CONCLUSIONS

Gastric emptying can be omitted from the treatment protocol for adults after acute oral overdose.

Home use of syrup of ipecac is associated with a reduction in pediatric emergency department visits

STUDY OBJECTIVE

To determine whether home use of syrup of ipecac is safe and effective in reducing pediatric emergency department visits.

DESIGN

Retrospective, multicenter comparison based on secondary use of a large database.

PARTICIPANTS

Children younger than 6 years after acute, accidental ingestion of a pharmaceutical product.

INTERVENTIONS

1990 Data corresponding to the study patients from seven regional poison centers were obtained from the American Association of Poison Control Centers. Poison center management choices (particularly use of syrup of ipecac for home decontamination) and characteristics (distribution of pharmaceutical ingestions managed, work volume per staff, staff experience, and training of decision-making director) were analyzed for their impact on the decision to refer a patient to a health care facility or to manage the patient at home. Statistical techniques included weighted least-squares regression analysis using logistic transformation of dependent variables and the forward selection procedure. Adverse patient outcome was defined as moderate effect, major effect, or death (American Association of Poison Control Centers coding criteria).

RESULTS

In all, 55,436 children were included in the analysis (range, 3,839 to 12,691 per poison center). The distribution of medications ingested was similar among centers. Increased home use of syrup of ipecac, decreased frequency of ingestion of "high-risk" drugs, and increased staff experience were associated with decreased referral to a health care facility (P < .0001 for each variable). The forward selection procedure determined that syrup of ipecac use explained 45% of the variation in the poison center referral rates. The percentage of drugs defined as high-risk accounted for an additional 31%, and staff experience accounted for another 10% of the variation. Outcome of patients was excellent. No child died. Two home-managed patients had a major effect, and 26 had a moderate effect.

CONCLUSION

Centers that recommended home use of syrup of ipecac more frequently were able to manage childhood poisoning more cost-effectively, without a decrease in safety. Although increased home management was strongly associated with syrup of ipecac use, the reason for this relationship cannot be determined from the data. Management by experienced professionals also contributed to cost-effectiveness.

Comparison of three methods of gut decontamination in tricyclic antidepressant overdose

The purpose of this study was to prospectively compare the effectiveness of three different gut decontamination methods in 51 patients presenting to an emergency department with tricyclic antidepressant overdose. Patients were randomized to three treatments; Group 1 received activated charcoal, Group 2 received saline lavage followed by activated charcoal, and Group 3 received activated charcoal followed by saline lavage followed by activated charcoal. Baseline characteristics of the three groups did not differ, including Glasgow Coma Scores, age, and mean tricyclic antidepressant levels. Average length of stay in admitted patients was 93.3 hours in Group 1, 107.2 hours in Group 2, and 66.7 hours in Group 3. Of those admitted to an ICU, average ICU time was 66.9 hours in Group 1, 54.1 hours in Group 2, and 34.4 hours in Group 3. Average duration of sinus tachycardia was 20.8 hours in Group 1, 30.8 hours in Group 2, and 32.2 hours in Group 3. Of those requiring mechanical ventilation, average ventilator time was 43.4 hours in Group 1, 24.1 hours in Group 2, and 17.8 hours in Group 3. No statistically significant difference could be shown with respect to the clinical endpoints noted. There were no deaths in any of the groups. All three methods of gut decontamination had similar clinical outcomes.

Successful treatment of amoxapine-induced refractory status epilepticus with propofol (diprivan)

Tonic-clonic seizure activity is a recognized complication of amoxapine overdose. Refractory drug-induced status epilepticus is associated with significant morbidity and mortality. Standard regimens for controlling status epilepticus may be ineffective for aborting drug-induced seizures. The authors report the case of a 30-year-old woman who presented with an amoxapine overdose that deteriorated into status epilepticus refractory to conventional therapy. Propofol given by intravenous bolus and maintenance infusion successfully halted the patient's seizure activity. This case suggests that propofol may be effective as an anticonvulsant in refractory drug-induced status epilepticus.

Objectives to direct the training of emergency medicine residents of off-service rotations: toxicology

Toxicology is an integral component in the training of the emergency physician. This is the 27th article in a continuing series of goals and objectives. The article provides basic guidelines for the organization of the toxicology elective with specific goals and objectives and a list of the contents of the toxicology briefcase. This information should aid in providing a comprehensive experience in toxicology for emergency medicine residents.

Influence of time until emesis on the efficacy of decontamination using acetaminophen as a marker in a pediatric population

STUDY OBJECTIVE

To determine the extent of drug removal by emesis at different times after the ingestion of a toxic substance.

DESIGN

Multicenter retrospective chart review.

METHODS

Using the American Association of Poison Control Centers' aggregate data base, children who had ingested acetaminophen and who were referred to a health care facility by one of 11 poison centers during a two-year period were identified. Charts of these patients were reviewed to determine the quantity ingested per kilogram of body weight, method of decontamination used, the timing of decontamination, and the serum acetaminophen concentration obtained four hours after ingestion.

RESULT

Charts of 455 patients met all requirements for inclusion. When emesis occurred within one-half hour after ingestion, mean serum acetaminophen concentration drawn four hours after ingestion was approximately half that in a control group that received no decontamination. Emesis had less impact when it was delayed further and had no demonstrable impact when it occurred more than 90 minutes after ingestion.

CONCLUSION

Many factors must be considered when deciding if and by what method a given patient should receive decontamination. When delayed gastric emptying is not expected, emesis can at best decrease a toxic burden by half if it occurs early. Medical care givers must continue to scrutinize management practice to ensure that syrup of ipecac is given only in situations in which it is likely to make a difference in outcome and in which it is the most effective agent to achieve this goal.

Gastrointestinal tract perforation with charcoal peritoneum complicating orogastric intubation and lavage

A rare complication of gastric decontamination occurred in a young woman undergoing treatment for tricyclic ingestion. After orogastric intubation and lavage, she developed an acute abdomen and underwent laparotomy. Charcoal was discovered throughout the peritoneum, but concurrent and subsequent efforts failed to localize a specific perforation site. Her hospital course was protracted and complicated by tenacious peritoneal charcoal deposition, persistent peritonitis, and adhesion and abscess formation. She underwent both percutaneous and open abscess drainage, oophorectomy, and small-bowel resection. She required total parenteral nutrition in addition to feeding jejunostomy. This present case constitutes the first report of the clinical consequences of charcoal peritoneum. Outright viscus perforation should be considered among potential complications of orogastric intubation and lavage in the poisoned patient. Methods to minimize risks of its occurrence are suggested.

Acute poisoning in Izmir, Turkey--a pilot epidemiologic study

Epidemiologic data on poisonings in Turkey are extremely limited. This is a retrospective chart review to describe the prevalence of poisoning in both adults and children, the presenting clinical features, morbidity and mortality to identify how poisoning in Izmir follows the pattern of other countries and how it is unique. Three hundred sixty-five poisoned patients presented to the Dokuz Eylül University Hospital, Ismir in 1989 to 1990. The distribution frequency of substances ingested reflects that of substances available in the home. Poisoning episodes in small children were most likely to involve hydrocarbons, analgesic, caustics or pesticides (55%). Ethanol, anticonvulsants, tricyclic antidepressants, and pesticides (55%). Ethanol, anticonvulsants, tricyclic antidepressants, and pesticides were the most common toxins seen in adults. A significant number of patients presented late in the course of their poisoning. Of those ingesting pharmaceuticals, mushrooms or plants, emesis, but no other modes of decontamination, was reported for 21%. Toxin "antidotes", gastrointestinal decontamination and enhanced drug removal techniques used in other parts of the world were rarely utilized. Nonetheless, only three patients (0.8%) died. This pilot study supports the need for a Regional Poison Information Center offering poison management advice to the general public as well as to members of the health care professions, the initiation of a public education campaign, and regional treatment by physicians trained in medical toxicology.

Update in medical toxicology

This article examines some current issues in toxicologic care. First there is a review of the scope of pediatric poisonings and some aspects of initial management. Then there is a discussion of the decision-making process required to properly use gastric decontamination in the management of poisonings. Each of the common methods available--emesis, gastric lavage, activated charcoal, catharsis, and whole bowel irrigation--is discussed. Finally, several new and old antidotes are reviewed, namely naloxone, glucagon, bicarbonate, dimercaptosuccinic acid, digoxin-specific fab fragments, and flumazenil.

Theophylline desorption from activated charcoal caused by whole bowel irrigation solution

Whole bowel irrigation with polyethylene glycol electrolyte lavage solution has been recommended as an adjunct to traditional overdose management. Although combined activated charcoal and whole bowel irrigation could enhance the efficacy of both modalities, this improvement remains largely speculative. An in vitro experiment was designed to determine whether polyethylene glycol electrolyte lavage solution alters the adsorption of theophylline to activated charcoal. Theophylline was agitated with activated charcoal in either water or polyethylene glycol electrolyte lavage solution, at each of three activated charcoal:theophylline ratios; 1:1, 3:1, and 10:1. The concentration in the supernatant was determined by high pressure liquid chromatography, and the maximal adsorptive capacity of activated charcoal for theophylline was calculated from the Langmuir equation. The percent of theophylline adsorbed by activated charcoal in water was 16 +/- 4%, 67 +/- 5%, and 97 +/- 3% for the 1:1, 3:1, and 10:1 ratios, respectively. This was decreased to 17 +/- 5%, 37 +/- 3%, and 62 +/- 2% when polyethylene glycol electrolyte lavage solution was added. A statistical difference (p less than 0.05) occurred at the 3:1 and 10:1 activated charcoal:theophylline ratios. Similarly the maximal adsorptive capacity was decreased 23% from 264 mg/g to 203 mg/g when polyethylene glycol electrolyte lavage solution was added to activated charcoal prior to theophylline. Polyethylene glycol electrolyte lavage solution significantly decreases adsorption of theophylline to activated charcoal in vitro. In vivo studies are required to confirm these findings. If activated charcoal is to be used clinically for theophylline toxicity, the authors suggest the possibility of larger quantities of activated charcoal, and administering activated charcoal in a slurry of water before the initiation of whole bowel irrigation.