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.

Accidental childhood iron poisoning: a problem of marketing and labeling.

Accidental iron poisoning still represents a significant hazard in children less than 5 years of age. The problem is compounded by the attractiveness of dosage forms, their high availability, and ambiguities in product labeling. Manufacturers accentuate label ambiguity by not specifically designating the iron as being total elemental iron or iron compound. A list of products that contain iron has been prepared to help clarify this issue.

Clinical applications of commonly used contemporary antidotes. A US perspective.

Poisonings are a common problem. In 1995, over 2 million exposures were reported to American poison information centres alone. The majority of poisoning exposures can be treated without major therapeutic intervention. If therapy is indicated, it is usually in the form of gastrointestinal decontamination with activated charcoal, to prevent absorption of the toxin and the subsequent toxicity that may occur. In a limited number of cases, more aggressive life-support measures may be necessary to treat the adverse effects of poisons. Occasionally, that intervention may include the use of pharmacological antagonists, more commonly referred to as antidotes. According to the American Association of Poison Control Centers, the most commonly used antidotes are acetylcysteine, naloxone, atropine, deferoxamine (desferrioxamine) and antivenins. Overall, 17 antidotes account for 99% of all antidote use and those agents are reviewed in this article. With the exception of naloxone, most antidotes have pharmacological effects that are independent of their inherent antidotal properties. Therefore, antidotes should be used judiciously because their pharmacological properties may exacerbate pre-existing toxicity and only in rare circumstances are they used prophylactically. Some antidotes, such as digoxin-specific antigen binding fragments (digoxin immune Fab), are very expensive, and both the risk: benefit ratio and the associated cost should be considered before the antidote is administered. The principle aims are to "treat the patient, not the poison' and to do no harm to the patient. Antidotes should be used only when they are indicated and may help a patient.

A comparison of the bioavailabilities of oral and intravenous ethanol in healthy male volunteers.

OBJECTIVES: Ethanol (EtOH), the antidote for methanol and ethylene glycol, is administered by the oral (PO) and intravenous (IV) routes. Serum concentrations (SCs) of 100 mg/dL or more are targeted for clinical effect. This study was completed to validate the assumption that there are minimal differences in SC achieved between these two routes. METHODS: Twenty healthy male volunteers were randomized to receive either PO or IV EtOH. Subjects abstained from EtOH for 48 hours before each phase. After a seven-day washout period, the subjects crossed over to the other group. Inclusion criteria were no history of medical problems, age between 21 and 40 years, and actual body weight within 10% of ideal weight. Baseline EtOH SCs were obtained before participation in each phase. Two hours after a standard breakfast, the subjects received 700 mg/kg of PO or IV EtOH. PO EtOH was administered as a 20% solution in juice over 10 minutes. IV EtOH, controlled by an infusion pump, was administered as a 10% solution over 30 minutes. Blood was drawn for EtOH SCs at 45, 75, 105, 135, 165, 225, 285, and 345 minutes after start of the dose. RESULTS: All initial EtOH SCs were 0. EtOH SCs were higher after IV administration. Mean peak SC was 103.6 mg/dL after IV administration and 71.3 mg/dL after PO administration (p<0.0001). Mean time to peak was 46.5 minutes after IV administration and 103.5 minutes after PO administration (p<0.0001). Total area under the curve was 17,440 min-mg/dL after IV administration and 13,875 min-mg/dL after PO administration (p<0.003). The order of treatments did not affect results (p>0.1). CONCLUSION: Significant differences exist between the SCs of EtOH as well as the times to peak SC after PO and IV administrations.

Treatment of acetaminophen overdose.

The therapeutic management of patients with acetaminophen overdose is reviewed. Acetaminophen overdose results in more calls to poison control centers in the United States than overdose with any other pharmacologic substance. Although the optimal management strategy remains controversial, the literature suggests a general approach that can be followed until there is evidence supporting a different strategy. A single dose of activated charcoal should be administered within one hour of acetaminophen overdose. Other means of gastric decontamination are not warranted. Acetylcysteine should be given if the acetaminophen concentration exceeds the treatment line in the Rumack-Matthew nomogram. If a patient is treated within 10 hours of acetaminophen ingestion, the risk of hepatoxicity is low. In patients 10-24 hours after ingestion, a 72-hour oral or 48-hour i.v. acetylcysteine regimen should be used. Among patients with fulminant hepatic failure, acetylcysteine should be given until recovery or death occurs. In patients who have taken extended-release acetaminophen, the acetaminophen concentration should be measured at four hours and, if this level exceeds the treatment line, acetylcysteine should be started immediately. If the concentration is below the treatment line, a second acetaminophen concentration should be determined four to six hours later. If this level is above the treatment line, acetylcysteine therapy should be started. Cimetidine appears to have no role in the management of acetaminophen overdose. Children should be diagnosed and treated the same way as adults, and pregnant patients should be managed no differently than nonpregnant patients. An evaluation of the literature on acetaminophen poisoning verifies the usefulness of acetylcysteine as a hepatoprotective agent. A single dose of activated charcoal may also be useful if given within one hour of acetaminophen ingestion.

Approach to the poisoned patient.

Routine poison management involves the following: (1) stabilization, (2) toxidrome recognition, (3) decontamination, (4) antidote administration, (5) enhanced elimination of toxin, and (6) supportive care. Stabilization involves airway, ventilation, and circulation support. In the patient with altered mental status, oxygen, naloxone, glucose, and thiamine should be administered. Symptom complexes that relate to specific classifications of toxins are referred to as toxidromes. Emesis by means of syrup of ipecac is rarely used for in-hospital gastric decontamination. Activated charcoal is a useful adsorbent for gastric decontamination. Whole bowel irrigation is useful for iron, lead, and lithium poisoning and for the body packer phenomenon. Enhancement of elimination may involve multiple doses of activated charcoal, hemodialysis, or charcoal hemoperfusion.

Environmental injuries.

Environmental injuries and illnesses can happen in home, work, or recreational settings. The variety and severity of these injuries might require the clinician to call on skills from internal medicine, emergency medicine, and toxicology. Diseases of thermoregulation are hypothermia and hyperthermia. In each instance, treatment is based on the need to restore the patient's core temperature to normal and on monitoring for complications. The victim of a fire might suffer inhalation injury in addition to burns, and it is more likely that the inhalation injury will be fatal. Oxygen deprivation and inhalation of irritant or asphyxiant chemicals contribute to injury. Toxic plants can be the source of poisoning emergencies, especially in children. Misinformation and myths that surround common plants can create diagnostic problems (i.e., which plants really are toxic and require emergency measures). Venomous marine organisms can cause a wide range of injury, from cutaneous eruption to fatal envenomation. Most are encountered in a recreational setting, such as water sports, but keepers of home aquariums are subject to stings from venomous fish. Lightning injury can present many diagnostic and treatment dilemmas. An important point in this regard is that lightning injury and high-voltage electrical injury are different in pathology and require different approaches for treatment. A discussion of electrical, chemical, and thermal burns makes such differences apparent.

Serotonin syndrome due to venlafaxine and maintenance tranylcypromine therapy.

A number of novel serotonergic antidepressants have been introduced to clinical practice over the last decade. These medications are felt to be safe alternatives to the traditional tricyclic antidepressants and monoamine oxidase inhibitors, particularly in the overdose setting. Serious adverse reactions and drug interactions have been appreciated and fatalities have been reported. We describe the development of the serotonin syndrome in a 60 year old female on chronic tranylcypromine treatment following the inadvertent ingestion of a single dose of venlafaxine. Manifestations included and altered mental status that progressed to hyperthermia and coma. She recovered quickly and without complications. Health care providers and poison specialists need to be aware that this potentially serious syndrome can be precipitated by a single dose of a serotonin reuptake inhibitor in patients being treated with a monoamine oxidase inhibitor.

Flumazenil reversal of carisoprodol (Soma) intoxication.

A 52-year-old woman presented with central nervous system depression and a Glasgow Coma Score of 9 secondary to ingestion of carisoprodol, a centrally acting muscle relaxant analgesic. After administration of i.v. flumazenil, the patient's neurologic status normalized and she required no further therapy. Carisoprodol and its active sedative-hypnotic metabolite, meprobamate, are gamma aminobutyric acid receptor indirect agonists with central nervous system chloride ion channel conduction effects similar to the benzodiazepines, thus making flumazenil a potentially useful antidote in toxic presentations.

Transdermal drug delivery system exposure outcomes.

Transdermal drug delivery systems are increasingly popular, yet few data exist regarding medical outcomes after exposures. Using data collected through a Regional Poison Information System, this retrospective study identified 61 cases of transdermal drug delivery system exposures reported over a recent 5-year period. Exposure routes included dermal (48 patients), oral (10 patients), combined oral and dermal (one patient), parenteral use of gel residue (one patient), and combined oral and parenteral (one patient). Forty-four exposures (72%) were managed by home telephone consultation only. Eleven of 17 patients (18%) evaluated in health care facilities were admitted, including eight (13%) to intensive care units. Hospital admission correlated statistically with clonidine and fentanyl exposures, oral exposures, and drug abuse. Clonidine exposure also correlated statistically with intensive care admission. One fatality was recorded, and all other patients recovered uneventfully. Transdermal drug delivery system exposures are infrequently reported to our regional poison information center but are associated with a significant hospital use and admission rate.

Dextromethorphan- and pseudoephedrine-induced agitated psychosis and ataxia: case report.

Pseudoephedrine and dextromethorphan are therapeutic constituents of numerous commonly used, over-the-counter cough and cold preparations. Although this drug combination is generally considered quite safe if utilized in recommended doses, overmedication or overdose can result in serious neurologic and cardiovascular abnormalities that occasionally can be life-threatening. We present a case of a 2-year-old child who developed hyperirritability, psychosis, and ataxia after being overmedicated with a pseudoephedrine/dextromethorphan combination cough preparation, and discuss probable mechanisms of toxicity and risk factors for adverse events.

Five-year multicenter retrospective review of cyclobenzaprine toxicity.

Cyclobenzaprine (CBP) has a cyclic structure similar to amitriptyline. In overdose, CBP has been suggested to produce the cardiovascular and neurologic toxicity found with the cyclic antidepressants. To examine this possibility, a retrospective chart review of all cases of CBP exposure reported to five regional poison centers was performed for the years 1989-93. There were a total of 750 charts identified for CBP exposure, of which 523 had data sufficient for evaluation. There were 121 polydrug ingestions leaving 402 pure CBP ingestions. Ages ranged from 7 mo to 77 yrs, with a mean of 20 yrs; 26% were 6 yrs or less. Females comprised 63% of the patient group. No deaths occurred. Dysrhythmias beyond sinus tachycardia were infrequent, and none were life-threatening. No seizures occurred. Common effects were lethargy, sinus tachycardia, and agitation, and both hypertension and hypotension were seen. All symptomatic cases with a known time of ingestion were symptomatic within 4 h of ingestion. Doses ingested ranged from 5-1000 mg, with a mean of 133 mg. Asymptomatic and symptomatic patients had a mean dose ingested of 45 mg and 183 mg, respectively. Treatment was primarily gastrointestinal (GI) decontamination and supportive care. Other therapies required were mechanical ventilation, dopamine, fluid bolus, sedation, and foley catheter. Symptoms requiring treatment beyond GI decontamination did not occur with ingestions less than 100 mg. In conclusion, cyclobenzaprine does not appear to produce the life-threatening cardiovascular or neurologic effects of the cyclic antidepressants in doses less than 1 g. Lethargy and anticholinergic effects are prominent, though serious toxicity is infrequent.

Acute phenolphthalein ingestion in children. A retrospective review.

The Patient Management Exchange for this edition of the Journal features a research study on phenolphthalein ingestion done at the Pittsburgh Poison Center. The purpose of selecting this article was twofold. First, the material presented about the management of phenolphthalein ingestion in children is valuable information for health care practitioners working in ambulatory settings. Second, this work is an excellent illustration of how research can be incorporated into one's clinical practice. This study also demonstrates that research does not always involve a long and cumbersome process. Instead, research can evolve from the need of health care professionals to answer a simple question that is raised about a particular aspect of their patient practice.

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.

Poison information centers save lives ... and money!

Poison information centers provide telephone advice on the treatment of poisonings to the lay public and medical professionals. In general, the services of a poison center are provided freely to the caller. However, poison center services are labor intensive and expensive since most poison centers utilize medical professionals to provide service and are available for consultation 24 hours/day. The failure of poison centers to produce revenue has made them vulnerable to closure. Poison centers provide a vital service to society by reducing morbidity and mortality. Often overlooked are the financial benefits of poison centers. By preventing unnecessary hospital admissions and by providing expert advice that may reduce the use of expensive antidotes and lengthy hospital admissions, poison centers save an estimated $6.50 for every dollar invested in their operation. The cost-effectiveness of poison centers is supported by a multitude of research. All entities that benefit from poison center services should assist in the financial support of poison centers.

The critical role of the Poison Center in the recognition, mitigation and management of biological and chemical terrorism.

Nuclear, biological and chemical (NBC) terrorism counter measures are a major priority with healthcare providers, municipalities, states and the federal government. Significant resources are being invested to enhance civilian domestic preparedness through training in anticipation of a NBC terroristic incident. The key to a successful response, in addition to education, is integration of efforts as well as thorough communication and understanding the role that each agency would play in an actual or impending NBC incident. In anticipation of a NBC event, a regional counter-terrorism task force was established in southwestern Pennsylvania to identify resources, establish responsibilities and coordinate the response to NBC terrorism. Members of the task force include first responders, hazmat, law enforcement (local, regional, national), government officials, health departments, the statewide emergency management agency and the regional poison information center. The poison center is one of several critical components of a regional counter-terrorism response force. It can conduct active and passive toxicosurveillance and identify sentinel events. To be responsive, the poison center staff must be knowledgeable about biological and chemical agents. The development of basic protocols and a standardized staff education program is essential. The use of the RaPID-T (R-recognition, P-protection, D-detection, T-triage/treatment) course can provide basic staff education for responding to this important but rare consultation to the poison center.

The contemporary management of poisoning emergencies.

Most patients who ingest toxic substances can be properly managed with basic supportive care, and only infrequently is more extensive intervention necessary. Basic supportive care includes the use of clinical toxicology's primary tools-syrup of ipecac, activated charcoal, and cathartics. Appropriate use of these agents decreases the morbidity and mortality associated with poisoning emergencies.

A model to improve the accuracy of US Poison Center data collection.

CONTEXT: Over 2 million human exposure calls are reported annually to United States regional poison information centers. All exposures are documented electronically and submitted to the American Association of Poison Control Center's National Poison Data System. This database represents the largest data source available on the epidemiology of pharmaceutical and non-pharmaceutical poisoning exposures. The accuracy of these data is critical; however, research has demonstrated that inconsistencies and inaccuracies exist. OBJECTIVE: This study outlines the methods and results of a training program that was developed and implemented to enhance the quality of data collection using acetaminophen exposures as a model. METHODS: Eleven poison centers were assigned randomly to receive either passive or interactive education to improve medical record documentation. A task force provided recommendations on educational and training strategies and the development of a quality-measurement scorecard to serve as a data collection tool to assess poison center data quality. Poison centers were recruited to participate in the study. Clinical researchers scored the documentation of each exposure record for accuracy. Results. Two thousand two hundred cases were reviewed and assessed for accuracy of data collection. After training, the overall mean quality scores were higher for both the passive (95.3%; + 1.6% change) and interactive intervention groups (95.3%; + 0.9% change). Data collection accuracy improved modestly for the overall accuracy score and significantly for the substance identification component. There was little difference in accuracy measures between the different training methods. CONCLUSION: Despite the diversity of poison centers, data accuracy, specifically substance identification data fields, can be improved by developing a standardized, systematic, targeted, and mandatory training process. This process should be considered for training on other important topics, thus enhancing the value of these data in relation to public health safety.