Gastrointestinal decontamination in the management of the poisoned patient

Ipecac syrup is the agent of choice to promote emesis in awake, alert, and cooperative patients who have ingested poison. Lavage is a reasonable alternative when ipecac fails or emesis is contraindicated. Activated charcoal is effective in minimizing absorption of ingested toxins, and saline cathartics may be useful to hasten the elimination of activated charcoal and possibly of enteric-coated or sustained release medications.     

Bowel perforation after single-dose activated charcoal

Patients presenting to the emergency department (ED) after medication overdose are often given activated charcoal initially for gastrointestinal decontamination. Complications of charcoal are rare, but do occur. The following case describes a patient with pre-existing undiagnosed diverticular disease who developed sigmoid perforation after a single dose of activated charcoal, given without cathartic for a drug overdose. A literature search revealed no other cases of bowel perforation associated with single-dose activated charcoal. This case report discusses adverse effects associated with activated charcoal and the role of cathartics in gastrointestinal decontamination.     

Position Paper: Cathartics

The administration of a cathartic alone has no role in the management of the poisoned patient and is not recommended as a method of gut decontamination. Experimental data are conflicting regarding the use of cathartics in combination with activated charcoal. No clinical studies have been published to investigate the ability of a cathartic, with or without activated charcoal, to reduce the bioavailability of drugs or to improve the outcome of poisoned patients. Based on available data, the routine use of a cathartic in combination with activated charcoal is not endorsed. If a cathartic is used, it should be limited to a single dose in order to minimize adverse effects of the Cathartic. A review of the literature since the preparation of the 1997 Cathartics Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.     

Acute poisoning emergencies. Resolving the gastric decontamination controversy.

As in all medical emergencies, in acute poisoning the cornerstone of management is good supportive care. Aggressive support of the cardiovascular, respiratory, and central nervous systems, along with appropriate gastric decontamination, greatly reduces morbidity and mortality and improves patient outcome. Ipecac is generally reserved for home use, where it can be given to induce emesis immediately after ingestion of toxins, and it is given only in cases of mild or moderate toxicity. Activated charcoal should replace ipecac in the emergency department for cases of mild or moderate toxicity. Gastric lavage and administration of activated charcoal should be considered in cases with life-threatening potential. A cathartic should be considered after activated charcoal has been administered, but only in cases where it will not have a detrimental effect.     

Gastrointestinal transit times of a charcoal/sorbitol slurry in overdose patients

Abstract

Gut decontamination with a slurry of activated charcoal and sorbitol is one of the methods presently available to decrease total body burden of ingested drug. This one year retrospective audit of patients presenting with a history of recent toxic ingestion was designed to determine the time to stool of a charcoal/sorbitol slurry (CSS) when used for differing ingestants. A total of 69 patients received a CSS. 50.7% took less than 6 hours for their first charcoal stool, while 26.1% had emesis of the CSS within 30 minutes of administration. Ingestion of drugs which may increase gastrointestinal transit time (i.e. opioids, cyclic antidepressants) correlated with prolonged time to stool despite treatment with the CSS. Though a prospective, controlled study needs to be performed, variation in dosage of the CSS may be appropriate in select patient groups to offset the effects of the ingestant on bowel motility.     

Position Statement: Cathartics

Abstract

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.

The administration of a cathartic alone has no role in the management of the poisoned patient and is not recommended as a method of gut decontamination. Experimental data are conflicting regarding the use of cathartics in combination with activated charcoal. No clinical studies have been published to investigate the ability of a cathartic, with or without activated charcoal, to reduce the bioavailability of drugs or to improve the outcome of poisoned patients. Based on available data, the routine use of a cathartic in combination with activated charcoal is not endorsed. If a cathartic is used, it should be limited to a single dose in order to minimize adverse effects.     

THE MECHANISM OF THE VOMITING INDUCED BY ANTIMONY AND POTASSIUM TARTRATE (TARTAR EMETIC)

1. It has been shown that tartar emetic acts on the stomach to induce emesis after its oral administration, that only traces are present in the vomitus following its intravenous injection (Kleimann and Simonowitsch), and that it does not induce emesis when it is applied directly to the vomiting center (Thumas). 2. In the present study, which was made with cats except when otherwise specifically stated, the intravenous injection of tartar emetic caused emesis (typical vomiting movements) after the removal of the entire gastrointestinal tract from the esophagus to the anus. 3. Cutting the vagi inhibits emesis after the intravenous injection of any dose of tartar emetic, though nausea may be induced. 4. Cutting the vagi and simultaneously extirpating the stellate ganglia inhibits both nausea and vomiting after the intravenous injection of tartar emetic. 5. Extirpation of the celiac ganglion and simultaneous cutting of the vagi just below the level of the diaphragm does not prevent emesis following the intravenous injection of tartar emetic. 6. Cutting the vagi prevents vomiting after the introduction of large doses of tartar emetic into the stomach, but massive doses may still cause emesis. Vagotomy probably has less influence on the emetic action of a moderately large dose of tartar emetic introduced into a loop of the duodenum. 7. Atropine has very nearly the same effect on the emetic action of tartar emetic as cutting the vagi, but much larger doses are necessary to abolish the effect of the introduction of tartar emetic into the stomach in moderate amounts than that of equal amounts injected intravenously. 8. The facts just stated point to the heart as the seat of reflex vomiting following the intravenous injection of tartar emetic. 9. The intravenous injection of tartar emetic induces afferent emetic impulses which pass from the heart to the vomiting center mainly by way of the vagus, to a much less extent by way of the sympathetic nerve and the stellate ganglia. 10. The introduction of tartar emetic into the stomach induces afferent emetic impulses which pass upward mainly by way of the vagus, to a much less extent by way of the sympathetic nerve. 11. The introduction of tartar emetic into the duodenum induces afferent emetic impulses which pass upward partly by way of the sympathetic nerve, partly by way of the vagus. 12. It seems probable that the path taken by afferent emetic impulses induced in the gastrointestinal tract by tartar emetic depends on the innervation of the organ concerned, and not on any selective action of the poison on the afferent nerve.     

Position Paper: Single-Dose Activated Charcoal

Single-dose activated charcoal therapy involves the oral administration or instillation by nasogastric tube of an aqueous preparation of activated charcoal after the ingestion of a poison. Volunteer studies demonstrate that the effectiveness of activated charcoal decreases with time. Data using at least 50 g of activated charcoal, showed a mean reduction in absorption of 47.3%, 40.07%, 16.5% and 21.13%, when activated charcoal was administered at 30 minutes, 60 minutes, 120 minutes and 180 minutes, respectively, after dosing. There are no satisfactorily designed clinical studies assessing benefit from single-dose activated charcoal to guide the use of this therapy.

Single-dose activated charcoal should not be administered routinely in the management of poisoned patients. Based on volunteer studies, 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 one hour previously. Although volunteer studies demonstrate that the reduction of drug absorption decreases to values of questionable clinical importance when charcoal is administered at times greater than one hour, the potential for benefit after one hour cannot be excluded. 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. A review of the literature since the preparation of the 1997 Single-dose Activated Charcoal Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.     

Position paper: Single-dose activated charcoal

Single-dose activated charcoal therapy involves the oral administration or instillation by nasogastric tube of an aqueous preparation of activated charcoal after the ingestion of a poison. Volunteer studies demonstrate that the effectiveness of activated charcoal decreases with time. Data using at least 50 g of activated charcoal, showed a mean reduction in absorption of 47.3%, 40.07%, 16.5% and 21.13%, when activated charcoal was administered at 30 minutes, 60 minutes, 120 minutes and 180 minutes, respectively, after dosing. There are no satisfactorily designed clinical studies assessing benefit from single-dose activated charcoal to guide the use of this therapy. Single-dose activated charcoal should not be administered routinely in the management of poisoned patients. Based on volunteer studies, 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 one hour previously. Although volunteer studies demonstrate that the reduction of drug absorption decreases to values of questionable clinical importance when charcoal is administered at times greater than one hour, the potential for benefit after one hour cannot be excluded. 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. A review of the literature since the preparation of the 1997 Single-dose Activated Charcoal Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.     

Pattern of orlistat exposures in children aged 5 years or less

On February 7, 2007, orlistat became the first weight-loss drug approved by the United States Food and Drug Administration for over-the-counter sales. However, information on exposures among young children is limited. The objective of this study was to describe the pattern of orlistat exposures among young children reported to poison control centers. The pattern of all exposures to orlistat alone among patients < or = 5 years old reported to six poison control centers during 1999-2005 was identified with respect to various factors. There were 107 cases. The average age was 21.4 months. There were 55 males, 51 females, and 1 unknown. The dose was identified for 76 cases. The mean dose was 155 mg. Patients were managed on site in 88% of the cases, were already at a health care facility in 8%, and were referred to a health care facility in 5%. Of the 45 patients with a known medical outcome, the outcome was no effect for 91% and minor effect for 9% of the patients. Of the 92 cases reported during 2000-2005, the listed adverse clinical effects were diarrhea (n = 4) and vomiting (n = 1), and the listed treatments were decontamination by dilution (n = 62), food (n = 8), activated charcoal (n = 5), other emetic (n = 2), cathartic (n = 1), and ipecac (n = 1). Orlistat exposures among young children involving small doses encountered by poison control centers can usually be managed on site through decontamination, and have favorable outcomes with few adverse clinical effects, mainly gastrointestinal in nature.     

Effect of Anticholinergic Drugs on the Efficacy of Activated Charcoal

Background: Although it is a commonly held belief that the ingestion of drugs with an anticholinergic action would prolong the duration of time after drug ingestion for effective gastrointestinal decontamination, data are lacking to support this belief. The purpose of this study is to determine whether activated charcoal is more effective in the presence of concurrent anticholinergic activity. Methods: A three‐limbed randomized crossover study in 10 healthy volunteers was completed to determine the ability of a 50 g dose of activated charcoal to reduce the bioavailability of a simulated overdose of acetaminophen (12 × 325 mg tablets) in the presence and absence of a concurrently present anticholinergic drug, atropine (0.01 mg/kg I. M. administered 15 min prior to the acetaminophen ingestion). Results: After the acetaminophen ingestion, median C_max occurred at 1 h for all three exposures but was lower in the atropine‐treated study arm (31 ± 19 mg/L) than in the control or charcoal alone intervention arms (49 ± 13 and 51 ± 16 mg/L, respectively) (P < 0.05). Compared to the control area under the serum concentration vs. time curve, a single dose of activated charcoal 1 h after drug ingestion reduced acetaminophen bioavailability by 20% (95% CI 4–36%) and by 47% (95% CI 35–59%) in the presence of atropine (P < 0.05 atropine plus charcoal vs. charcoal alone). Conclusions: Our data support the belief that activated charcoal is more effective in the presence of anticholinergic activity. Additional study is required to determine whether in patients with anticholinergic drug overdose, activated charcoal is effective at times beyond the recommendation for overdoses of drugs without this pharmacodynamic effect.     

Pharmacological MRI in awake rats reveals neural activity in area postrema and nucleus tractus solitarius: relevance as a potential biomarker for detecting drug-induced emesis

Drug-induced vomiting (emesis) is a major concern in patient care and a significant hurdle in the development of novel therapeutics. With respect to the latter, rodents, such as the rat and mouse, are typically used in efficacy and safety studies; however, drug-induced emesis cannot be readily observed in these species due to the lack of an emetic reflex. It is known that emesis can be triggered by neural activity in brain regions including area postrema (AP) and nucleus tractus solitarius (NTS). In this study, using pharmacological magnetic resonance imaging (phMRI) and a blood-pool contrast agent, we imaged the hemodynamic consequences of brain activity in awake rats initiated by the administration of compounds (apomorphine 0.1, 0.3 micromol/kg i.v. and ABT-594 0.03, 0.1, 0.3 micromol/kg i.v.) that elicit emesis in other species. Regional drug-induced relative cerebral blood volume (rCBV) changes and percent activated area within the AP and NTS were calculated, in which a dose-dependent relationship was evident for both apomorphine and ABT-594. Additionally, to correlate with behavioral readouts, it was found that the activation of AP and NTS was observed at plasma concentrations consistent with those that induced emesis in ferrets for both drugs. Our data thus suggest that phMRI in awake rats may be a useful tool for predicting emetic liability of CNS-acting drugs and may provide insights into depicting the underlying emetic neural pathways in vivo.     

Acupressure for Prevention of Emesis in Patients Receiving Activated Charcoal

Objective: Vomiting after activated charcoal decontamination is problematic. Acupressure (traditional Chinese medicine) is an effective treatment for emesis, but has not been tested in overdose patients. We sought to determine (1) the incidence of emesis after activated charcoal and (2) the ability of acupressure to prevent emesis due to activated charcoal. Methods: Consecutive overdose patients were enrolled in a preliminary, prospective study to determine the incidence of emesis after activated charcoal. Awake patients, >18 years, received 1 g/kg activated charcoal orally or via nasogastric tube, and then observed for 1 hour. These patients served as controls for part 2 of the study, where acupressure bands were placed on overdose patients at the Nei-Guan P-6 point of both wrists prior to activated charcoal, followed by 1 hour observation. Exclusion criteria included: ipecac decontamination, antiemetic drug ingestion, antiemetic drug therapy within 1 hour of activated charcoal, or intubation. Results: Eighty-one patients were included in the control group and 106 patients in the acupressure treatment group. Demographics and ingested substances were similar in both groups. 21/81 (25.9%) in the control group vomited and 15/106 (14.2%) in the acupressure group vomited. Acupressure reduced emesis by 46% (p=0.043; χ²). Within the acupressure group, the median duration of prophylactic acupressure was 5 minutes in those patients without vomiting compared to 4 minutes in those patients with vomiting (NS; Wilcoxon rank sum test). Conclusion: The incidence of emesis after activated charcoal at our institution was 26%. Prophylactic acupressure reduced activated charcoal-induced vomiting by 46%. Investigators suggest 5 minutes of acupressure prior to activated charcoal.     

Recognition and management of acute pesticide poisoning

Most poisonings from pesticides do not have a specific antidote, making decontamination the most important intervention. For maximal benefit to the patient, skin, eye, and gastric decontamination should be undertaken while specifics of the poisoning are being determined. As in most illnesses and injuries, the history of the poisoning is of great importance and will determine specific needs for decontamination and therapy, if any exist. Protection of health care workers during the decontamination process is important and frequently overlooked. Skin decontamination is primarily accomplished with large volumes of water, soap, and shampoo. Gastric decontamination by lavage is indicated if ingestion of the poisoning has occurred within 60 minutes of patient presentation. Activated charcoal, combined with a cathartic, is also indicated in most poisonings presenting within 60 minutes of ingestion. With large volume ingestion poisonings, activated charcoal may be used after 60 minutes, but little data exist to support this practice. Syrup of ipecac is no longer recommended for routine use. The cholinergic syndrome "all faucets on" characterizes poisoning by organophosphates and carbamates. Organochlorine insecticides (lindane and other treatments for scabies and lice) can produce seizures with excessive use or use on large areas of nonintact skin. Non-dipyridyl herbicides, biocides (including pyrethrins, pyrethroids, and Bacillus thuringiensis) rarely produce anything other than mild skin, eye, and/or gastrointestinal irritation on topical exposure or ingestion.     

Dextromethorphan poisoning: an evidence-based consensus guideline for out-of-hospital management

The objective of this guideline is to assist poison center personnel in the appropriate out-of-hospital triage and initial out-of-hospital management of patients with a suspected ingestion of dextromethorphan by 1) describing the process by which an ingestion of dextromethorphan might be managed, 2) identifying the key decision elements in managing cases of dextromethorphan ingestion, 3) providing clear and practical recommendations that reflect the current state of knowledge, and 4) identifying needs for research. This guideline applies to the ingestion of dextromethorphan alone. Co-ingestion of additional substances could require different referral and management recommendations depending on the combined toxicities of the substances. This guideline is based on an assessment of current scientific and clinical information. The expert consensus panel recognizes that specific patient care decisions might be at variance with this guideline and are the prerogative of the patient and the health professionals providing care, considering all of the circumstances involved. This guideline does not substitute for clinical judgment. The grade of recommendation is in parentheses. 1) All patients with suicidal intent, intentional abuse, or in cases in which a malicious intent is suspected (e.g., child abuse or neglect) should be referred to an emergency department (Grade D). 2) Patients who exhibit more than mild effects (e.g., infrequent vomiting or somnolence [lightly sedated and arousable with speaking voice or light touch]) after an acute dextromethorphan ingestion should be referred to an emergency department (Grade C). 3) Patients who have ingested 5-7.5 mg/kg should receive poison center-initiated follow-up approximately every 2 hours for up to 4 hours after ingestion. Refer to an emergency department if more than mild symptoms develop (Grade D). 4) Patients who have ingested more than 7.5 mg/kg should be referred to an emergency department for evaluation (Grade C). 5) If the patient is taking other medications likely to interact with dextromethorphan and cause serotonin syndrome, such as monoamine oxidase inhibitors or selective serotonin reuptake inhibitors, poison center-initiated follow-up every 2 hours for 8 hours is recommended (Grade D). 6) Patients who are asymptomatic and more than 4 hours have elapsed since the time of ingestion can be observed at home (Grade C). 7) Do not induce emesis (Grade D). 8) Do not use activated charcoal at home. Activated charcoal can be administered to asymptomatic patients who have ingested overdoses of dextromethorphan within the preceding hour. Its administration, if available, should only be carried out by health professionals and only if no contraindications are present. Do not delay transportation in order to administer activated charcoal (Grade D). 9) For patients who have ingested dextromethorphan and are sedated or comatose, naloxone, in the usual doses for treatment of opioid overdose, can be considered for prehospital administration, particularly if the patient has respiratory depression (Grade C). 10) Use intravenous benzodiazepines for seizures and benzodiazepines and external cooling measures for hyperthermia (>104 degrees F, >40 degrees C) for serotonin syndrome. This should be done in consultation with and authorized by EMS medical direction, by a written treatment protocol or policy, or with direct medical oversight (Grade C). 11) Carefully ascertain by history whether other drugs, such as acetaminophen, were involved in the incident and assess the risk for toxicity or for a drug interaction.     

Activated charcoal alone and followed by whole-bowel irrigation in preventing the absorption of sustained-release drugs

OBJECTIVE: Our objective was to study the effect of activated charcoal on the absorption of sustained-release drugs ingested 1 hour earlier and to examine whether whole-bowel irrigation affects the efficacy of charcoal. METHODS: In this randomized, 3-phase crossover study, 9 healthy subjects received, at the same time, 200 mg carbamazepine, 200 mg theophylline, and 120 mg verapamil. All drugs were given as sustained-release tablets. One hour after taking the tablets, the subjects were assigned to one of the following treatments: 25 g activated charcoal as a suspension, 25 g activated charcoal as a suspension followed by whole-bowel irrigation with polyethylene glycol (PEG) electrolyte lavage solution, or 200 mL water (control). The absorption of the drugs was characterized by using the area under the plasma drug concentration-time curve from time zero to 24 hours [AUC(0-24)], peak plasma concentration (C(max)), C(max) minus the plasma concentration at 1 hour (C(Delta)), and time to peak (t(max)). RESULTS: Activated charcoal alone given 1 hour after drug intake significantly (P <.001) reduced the absorption [AUC(0-24)] of all 3 drugs (by 62%-75%). Also the C(max) and C(Delta) values of these drugs were significantly reduced by charcoal alone. Whole-bowel irrigation did not increase significantly the effect of charcoal on any absorption parameters of the 3 drugs studied. On the contrary, whole-bowel irrigation significantly (P <.01) decreased the efficacy of charcoal with respect to carbamazepine. CONCLUSIONS: Activated charcoal alone given 1 hour after intake of sustained-release drugs was effective in preventing the absorption of all 3 drugs studied. Whole-bowel irrigation may even decrease the efficacy of charcoal if the drug is well adsorbable onto charcoal. However, our study was performed with therapeutic drug doses only. In overdoses their possible effects on gastrointestinal motility may modify the efficacy of decontamination methods.     

Fab fragments in the treatment of digoxin overdose: pediatric considerations

Serious digoxin toxicity due to accidental or deliberate overdose is uncommon, but more than half of the cases reported in 1985 involved children. Toxicity can occur acutely, as with accidental overdose, or with long-term maintenance dosing. In children it is almost always acute. Conventional treatment includes gastric lavage or ipecac-induced emesis, and activated charcoal or nonabsorbable resins and cathartics to reduce absorption. Although children appear to tolerate massive ingestions without specific therapy, serum digoxin levels must be reduced quickly and safely when conventional measures have failed. Fab fragments of digoxin-specific antibodies have been successfully used to treat refractory digoxin toxicity. Indications for use should be limited to life-threatening digoxin toxicity when conventional therapy has failed.     

Gastrointestinal obstruction associated with multiple-dose activated charcoal

The development of a gastrointestinal obstruction associated with multiple doses of activated charcoal is described. A carbamazepine-intoxicated patient received 240 g of activated charcoal and a total of 600 mL magnesium citrate with the development of an ileus and a small-bowel obstruction. The patient also had episodes of emesis associated with charcoal administration. This case suggests that the use of multiple doses of activated charcoal may be associated with gastrointestinal obstruction, a previously unreported adverse effect. Further evaluation of the incidence of adverse effects associated with activated charcoal is needed to determine optimal therapeutic regimens.     

Position Paper: Whole Bowel Irrigation

Whole bowel irrigation (WBI) should not be used routinely in the management of the poisoned patient. Although some volunteer studies have shown substantial decreases in the bioavailability of ingested drugs, no controlled clinical trials have been performed and there is no conclusive evidence that WBI improves the outcome of the poisoned patient. Based on volunteer studies, WBI should be considered for potentially toxic ingestions of sustained‐release or enteric‐coated drugs particularly for those patients presenting greater than two hours after drug ingestion. WBI should be considered for patients who have ingested substantial amounts of iron as the morbidity is high and there is a lack of other options for gastrointestinal decontamination. The use of WBI for the removal of ingested packets of illicit drugs is also a potential indication. WBI is contraindicated in patients with bowel obstruction, perforation, ileus, and in patients with hemodynamic instability or compromised unprotected airways. WBI should be used cautiously in debilitated patients or in patients with medical conditions that may be further compromised by its use. The concurrent administration of activated charcoal and WBI may decrease the effectiveness of the charcoal. The clinical relevance of this interaction is uncertain. A review of the literature since the preparation of the 1997 Whole Bowel Irrigation Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.