Lack of toxicity from pediatric beta-blocker exposures

The risk of toxicity in a child who is unintentionally exposed to a beta-blocking drug remains uncertain. The current study further defines this risk, particularly in the common scenario of ingestion of one or two tablets. A prospective cohort of 208 pediatric patients, 6 months to 6 years of age, reported to two regional poison centers serves as the study population. Data were collected with a standardized instrument during the care of each patient and for a minimum of 24 hours after exposure. No instances of serious toxicity typical of beta-blocker intoxication, such as ‘shock-like’ states, arrhythmias or seizures were observed in this series. Furthermore, there were no reported episodes of hypoglycemia, symptomatic bradycardia or bronchospasm. Nine instances of altered mental status or behavioral changes were reported. All appeared to be minor in nature. The most serious outcome was charcoal aspiration during gastrointestinal decontamination. This study adds to a growing body of evidence suggesting that exposure to one or two beta-blocker tablets places children at very little, if any, risk of toxicity.

Multicenter case series of valproic acid ingestion: serum concentrations and toxicity

BACKGROUND

Valproic acid exposures reported to poison centers have increased more than 4-fold over the last 5 years. There are no large case series published on valproic acid ingestion.

METHODS

A prospective multicenter case series of all patients reporting an ingestion of valproic acid. Data collected included: age, gender, dose ingested, concomitant medications, symptoms and vital signs, laboratory values, length of hospital stay, and medical outcome. Entrance into the study required a serum valproic acid concentration above the therapeutic threshold of 100 microg/mL. Statistical analysis was by Fisher's exact test.

RESULTS

A total of 335 patients were reported to participating centers of which 186 (55%) had serum valproic acid concentrations greater than 100 microg/mL. Of the 186 cases, 53 were multiple drug exposures leaving 133 cases of sole valproic acid ingestion for evaluation. Age ranged from 2 to 66 years with a mean of 30.1 years +/- 12. Peak serum valproic acid concentrations ranged from 110 microg/mL to 1840 microg/mL with a mean of 378.3 microg/mL +/- 310.2 microg/mL. Time from postingestion to the peak measured valproic acid concentration ranged from 1 to 18 hours, with a mean of 7.4 hours +/- 3.9. Symptoms included lethargy (n = 94), coma (n = 19), tachycardia (n = 24), aspiration (n = 8), metabolic acidosis (n = 8), and hypotension (n = 4). A peak concentration of > 450 microg/mL was more likely to be associated with a moderate or major adverse outcome (p < 0.005). A peak concentration > 850 microg/mL was more likely to be associated with coma (p < 0.005) and acidosis (p < 0.005). Eleven patients experienced transient thrombocytopenia (platelets < 150,000) and all had peak valproic acid concentrations >450 microg/mL. Four patients experienced transient leukopenia (WBC < 3,500). The mean hospital stay for all patients was 42 +/- 33.1 hours. A hospital stay > 48 hours was more likely to be associated with a peak valproic acid concentration > 450 microg/mL (p < 0.05). There were 2 fatalities.

CONCLUSIONS

In this case series, patients with peak valproic acid concentrations above 450 microg/mL were more likely to develop significant clinical effects and have longer hospital stays. A peak valproic acid concentration above 850 microg/mL was more likely to be associated with coma, respiratory depression, aspiration, or metabolic acidosis.

Multicenter case series of pediatric metformin ingestion

OBJECTIVE

There are no large studies, case series, or case reports of metformin ingestion in children. This study summarizes the clinical course and outcomes of metformin ingestion in children reported to the American Association of Poison Control Centers-certified regional poison centers.

METHODS

This was a case series of all metformin ingestions in patients <18 years of age reported to eight regional poison centers. Data collection included age, gender, dose ingested, co-ingestants, symptoms, vital signs, laboratory values, length of hospital stay, and medical outcome. Entrance into the study required at least 24 hours of follow-up.

RESULTS

Fifty-five cases were collected. Ages ranged from 15 months to 17 years, with a mean (+/- SD) of 42+/-4.4 years. The dose ingested, by history, ranged from 250 mg to 16.5 g, with a mean and median of 1710+/-3391 and 500 mg, respectively. Forty-one children (76%) ingested a maximum of two tablets (< or =1700 mg). In the children younger than six years, dosage ranged from 9 to 196 mg/kg, with a mean and median of 60+/-41.1 and 40 mg/kg, respectively. Thirty-seven children were evaluated in a healthcare facility. Clinical effects were limited to nausea (2), diarrhea (2), and dizziness (1). None of the 38 children who had serial glucose measurements experienced hypoglycemia. Arterial blood gas and electrolyte measurements were performed in three and 19 children, respectively. No evidence of acidosis was demonstrated. Two children had lactate concentrations measured and were determined to be in the normal range. Twenty-nine patients received activated charcoal. Five patients received parenteral glucose and one adolescent with a history of diabetes received insulin for hyperglycemia.

CONCLUSIONS

Unintentional ingestion of < or =1700 mg of metformin in the healthy pediatric population does not appear to pose a significant health risk of hypoglycemia or detrimental outcome. In the 21 children who were tested for either blood glucose, electrolyte, or lactate concentrations, no evidence of lactic acidosis was seen.

Efficacy of the cation exchange resin, sodium polystyrene sulfonate, to decrease iron absorption

BACKGROUND

Iron is not bound by charcoal; therefore, a method of binding iron in the gastrointestinal tract to prevent absorption in iron overdose is needed. This study investigated the efficacy and safety of sodium polystyrene sulfonate to prevent absorption of iron in human volunteers.

METHODS

Six adult volunteers completed this prospective crossover trial. Following an oral dose of elemental iron 10 mg/kg, each subject received sodium polystyrene sulfonate 30 g or water as control. Baseline and serial serum iron samples were drawn to determine pharmacokinetic parameters.

RESULTS

A trend toward increased time to peak following sodium polystyrene sulfonate compared to the control arm (5.7 vs 3.6 hours) was observed but was not statistically significant (p = 0.517). A trend toward smaller area-under-the-curve for the sodium polystyrene sulfonate was evident but was not statistically significant (p = 0.77). Iron concentration increased on average 298 mcg/dL and 370 mcg/dL above baseline in the treatment and control arms (p = 0.44). Sodium polystyrene sulfonate is not an effective method of decontamination for iron overdose.

Acute beta blocker overdose: factors associated with the development of cardiovascular morbidity

OBJECTIVE

To identify factors in exposures to beta blockers (beta-adrenergic receptor antagonists) that are associated with the development of cardiovascular morbidity and contribute to disposition decisions from the emergency department.

METHODS

Prospective cohort of 280 beta blocker exposures reported to 2 regional poison centers. Multiple logistic regression was used to determine association of various clinical factors and outcome.

RESULTS

In this series of beta blocker exposures, 41 (15%) developed cardiovascular morbidity and 4 (1.4%) died. A history of cardioactive coingestant was the only factor significantly associated with the development of cardiovascular morbidity (p < .05). When cases reporting cardioactive coingestants were excluded, a history of ingesting a beta blocker with membrane stabilizing activity was significantly associated with the development of cardiovascular morbidity (p < .05). All those in whom the timing of symptoms could be determined, developed symptoms within 6 hours of ingestion.

CONCLUSIONS

The single most important factor associated with the development of cardiovascular morbidity in beta blocker ingestion is a history of a cardioactive coingestant, primarily calcium channel blockers, cyclic antidepressants, and neuroleptics. In the absence of such coingestion, exposure to a beta blocker with membrane stabilizing activity is associated with an increased risk of cardiovascular morbidity. Beta blocker ingestion is unlikely to result in symptoms if the patient remains asymptomatic for 6 hours after the time of ingestion.

Toxicity of polysaccharide--iron complex exposures reported to poison control centers

OBJECTIVE

To evaluate the toxicity of polysaccharide-iron complex (PIC) exposures reported to poison centers in the US.

DESIGN

A retrospective analysis of potentially toxic exposures to PIC without concomitant substances reported to the American Association of Poison Control Centers (AAPCC) Toxic Exposure Surveillance System from 1990 to 1998 was performed.

RESULTS

Of 810 potentially toxic exposures to PIC, 55.9% occurred in females, 43.8% in males; in 0.3%, gender was unknown. The majority of exposures (74.4%) involved children under six years of age. The reasons for exposure were: 86.7% unintentional, 11.6% intentional, and 1.6% adverse reaction. The most frequently reported clinical effects attributed to PIC were vomiting (n = 23), diarrhea (10), nausea (11), abdominal pain (10), and lethargy/drowsiness (7). While the majority of exposures were managed outside a healthcare facility, management site varied depending on age (management in non-healthcare facility in 71.8% of exposures in children under six years of age vs. 44.9% in adolescents and adults). The majority of outcomes (95.6%) were no effect, minor effect, unrelated effect, not followed since nontoxic, or not followed since only minimal toxicity possible. Of two cases coded as moderate effect, it could not be determined whether the symptoms were related to PIC in one, and in the second case inspection of the poison center record revealed that the actual outcome was minor effect. There were no major effects or deaths.

CONCLUSIONS

There were no serious adverse events following PIC exposure reported to the AAPCC. Although more data are needed, these findings suggest reduced toxicity for PIC relative to other forms of iron.

Donepezil overdose: a tenfold dosing error

OBJECTIVE

To report toxicity resulting from donepezil administration following a tenfold dosing error.

CASE SUMMARY

A 79-year-old white nursing home patient with a history of Alzheimer disease and hypertension was inadvertently given 50 mg of donepezil instead of her usual 5-mg dose. She presented to the emergency department with nausea, vomiting, and persistent bradycardia (HR in the 40s). Routine laboratory studies were all within normal limits. Basilar rales were noted five hours after arrival. She was treated with atropine 0.2 mg as needed for bradycardia (HR <50 beats/min); a total of 3.0 mg was administered over 18 hours. Each bolus kept her HR >60 beats/min for one-half to two hours. No further vomiting or evidence of pulmonary edema occurred after her initial episodes. She returned to baseline by day 2 (HR in the 70s) and was returned to the nursing home.

DISCUSSION

Donepezil is a centrally acting, reversible cholinesterase inhibitor that is used in the treatment of Alzheimer disease. Donepezil is highly specific for neural acetylcholinesterases, preferentially binding acetylcholinesterase by greater than three orders of magnitude over butyrylcholinesterases. This specificity minimizes peripheral adverse effects at therapeutic doses. Our patient mainly experienced bradycardia and had minimal secretory effects compared with what is usually seen with nonspecific cholinesterase inhibition. Medication errors like the one that produced this overdose are a common but preventable cause of morbidity in healthcare facilities.

CONCLUSIONS

A tenfold dosing error caused donepezil toxicity. The main effect of this overdose was bradycardia, which responded to atropine therapy.

Accidental and suicidal adolescent poisoning deaths in the United States, 1979-1994

OBJECTIVE

To describe the epidemiological features of poisoning deaths in adolescents in the United States.

DESIGN

Descriptive analysis of poisoning deaths in persons aged 10 to 19 years in the United States from January 1, 1979, to December 31, 1994, based on national mortality data.

STUDY POPULATION

Adolescents whose cause of death was identified as poisoning using International Classification of Diseases, Ninth Revision codes.

MAIN OUTCOME MEASURE

Nature of injury (accident vs suicide).

RESULTS

There were 4129 suicides and 3807 accidental deaths due to poisoning. Victims were most frequently male and white. However, poisoning was more often the method of suicide in adolescent girls than in boys (28.0% vs 8.7%). The number of deaths (7138 vs 798) and death rate (2.36 vs 0.28 per 100,000 population) were higher in 15- to 19-year-olds vs 10- to 14-year-olds. The distribution of substances involved was different for 10- to 14-year-olds compared with 15- to 19-year-olds and for suicides compared with accidents. Among 10- to 14-year-olds, drugs other than alcohol accounted for 232 (85.3%) of 272 suicides but only 118 (22.4%) of 526 accidental deaths. Gases and vapors played an important role in accidental deaths and suicides in 15- to 19-year-olds and in accidents in 10- to 14-year-olds.

CONCLUSIONS

The rates of suicides and accidental poisoning deaths were lower in 10- to 14-year-olds compared with 15- to 19-year-olds. Areas where injury-prevention efforts might have an influence on adolescent fatalities include management of depression, substance abuse education, and use of carbon monoxide detectors or shutoff switches.

Prolonged formation of methemoglobin following nitroethane ingestion

BACKGROUND

Artificial nail removers containing nitroethane pose a serious risk of toxicity when ingested.

CASE REPORTS

We report 3 cases of children under 3 years of age who developed prolonged methemoglobinemia following ingestions of small quantities of these nitroethane-containing products. Methylene blue therapy reduced the methemoglobin level in all 3 children; however, in 2 of these children methemoglobin levels increased again several hours later and required additional methylene blue. Accurate substance identification is essential for appropriate management of ingestions of fingernail products. The availability of nitroethane products for home use should be questioned.

Agricultural and horticultural chemical poisonings: mortality and morbidity in the United States

STUDY OBJECTIVE

To provide a comprehensive analysis of morbidity and mortality from poisoning by agricultural and horticultural chemicals in the United States.

METHODS

Descriptive analysis of national mortality data, National Hospital Discharge Survey data, and American Association of Poison Control Centers national data for 1985 through 1990.

RESULTS

There were 341 fatalities from agricultural and horticultural chemicals over the 6-year period, of which 64% were suicides, 28% were unintentional, and 8% were of undetermined intent. There were 25,418 hospitalizations; 78% were reported to be unintentional. Both deaths and hospitalizations occurred more frequently in males, and rates were higher in nonwhites than in whites. There were 338,170 poison exposures reported to poison centers for fungicides, herbicides, pesticides/insecticides, and rodenticides. Life-threatening manifestations or long-term sequelae occurred in 782 cases, and 97 deaths were reported. Pesticides and insecticides accounted for 72% of the poison center cases and 63% of the fatalities. Although they accounted for only 8% of poison exposures, herbicide deaths were disproportionately high (25%).

CONCLUSION

Poisonings with agricultural and horticultural chemicals are an important public health problem. Prevention efforts need to incorporate the fact that many serious cases, such as paraquat poisonings, are suicidal in nature.

Analysis of sertraline-only overdoses

Sertraline is an antidepressant for which preliminary data suggest a low inherent toxicity. Previously reported case series have included coingestants or had small numbers of patients. This study was undertaken to determine the toxicity of overdoses of sertraline alone. A 2-year retrospective and 6-month prospective study was conducted at a regional poison center. There were 52 patients with a mean age of 19.3 +/- 13.8 years and a mean dose of 727 +/- 686 mg. There were no symptoms in 34 cases. Symptomatic patients experienced mild central nervous system, cardiovascular, and gastrointestinal effects. Two patients developed bradycardia which resolved without therapy. While all but 3 of 38 adolescents and adults were treated in a health care facility, 10 of 14 children were managed at home. Gastrointestinal decontamination was performed in 37 cases. No other specific therapy was required. Serious toxicity would not be expected following sertraline-only overdoses.

Use of activated charcoal in a simulated poisoning with acetaminophen: a new loading dose for N-acetylcysteine?

STUDY OBJECTIVES

To investigate the ability of a supranormal dose of N-acetylcysteine to overcome the effects of activated charcoal on N-acetylcysteine bioavailability and to determine the effects of activated charcoal on serum acetaminophen levels.

DESIGN, SETTING, AND PARTICIPANTS

Ten healthy adult volunteers participated in a controlled cross-over experiment. During phase I (control), subjects ingested 3 g acetaminophen, followed one hour later by the normal loading dose of N-acetylcysteine (140 mg/kg). During phase II (charcoal), subjects ingested 3 g acetaminophen, followed one hour later by 60 g activated charcoal and a supranormal loading dose of N-acetylcysteine (235 mg/kg).

MAIN OUTCOME MEASURES

Serum levels of N-acetylcysteine were measured every 30 minutes for six hours. A serum acetaminophen level was measured at four hours.

RESULTS

The area under the curve for N-acetylcysteine was significantly higher for phase II than phase I (P < .05, two-tailed paired t-test). Peak N-acetylcysteine and time to peak were not significantly different. The four-hour serum acetaminophen level was significantly lower for phase II than phase I (P < .05, two-tailed paired t-test). Diarrhea occurred during both phases, but N-acetylcysteine was otherwise well tolerated.

CONCLUSION

These results suggest that activated charcoal can be used safely for victims of acetaminophen overdose. A beneficial effect in preventing acetaminophen absorption can be expected if it is given within one hour after ingestion. If N-acetylcysteine is needed because of a toxic serum acetaminophen level, bioavailability can be ensured by increasing the N-acetylcysteine loading dose from 140 mg/kg to 235 mg/kg.

Initial symptoms as predictors of esophageal injury in alkaline corrosive ingestions

The predictive value of initial clinical evaluation in the management of alkaline corrosive ingestion remains unclear. This multicenter study was designed to determine if specific clinical signs and symptoms following ingestion of alkaline corrosives could predict significant esophageal injury. Alkaline corrosives were defined by a pH greater than or equal to 12. Signs and symptoms previously suggested as predictive of significant esophageal injury were documented on a standardized data form. Esophagoscopy reports were reviewed blinded to initial symptoms. Three hundred thirty-six alkaline-corrosive ingestions were analyzed. The mean number of symptoms reported in patients who did not have esophagoscopy was 1.2, in patients who had esophagoscopy was 3.0, and in patients that had visualized second or third degree esophageal burns was 4.8. Of 88 patients who had esophagoscopy, 63 (72%) had both the esophagoscopy report and initial symptom assessment available. Esophagoscopy was positive, defined as second or third degree esophageal burns, in 18 of 63 cases (29%). All patients with significant burns were symptomatic. No single or group of initially reported signs and symptoms could identify all patients with potentially serious esophageal burns.

Denatonium benzoate: review of efficacy and safety

The efficacy and toxicity studies on denatonium benzoate are limited and may be subject to varying interpretations when viewed in the context of a potential poisoning situation. Efficacy studies to date in children have shown that in a controlled environment, addition of denatonium benzoate to an otherwise palatable liquid will decrease the volume ingested. Important considerations include the fact that the number of studies are small (two utilizing orange juice as the liquid; one using a dilute liquid detergent), and these studies involved single-test situations wherein the liquid was available to the child for a limited period of time. Inadequate data are available to analyze one orange juice study and in the other study, 7 of 30 children took more than one swallow. Depending on the "pleasantness" of the liquid (color, smell, similarity to 'drinkable' liquids in appearance) prior to addition of denatonium, it is possible that children may take more than one swallow. Toxicity data indicate a low toxicity profile. However, there are significant gaps in our knowledge, especially relating to chronic toxicity in humans, teratogenicity, and human hypersensitivity potential. The role of denatonium benzoate in preventing serious poisonings has yet to be defined. Aversive agents such as denatonium should augment but not replace proven methods of poison prevention including parental education and child-resistant closures. When selecting products for inclusion of denatonium benzoate, consideration should be given to the inherent toxicity of the product as well as the potential for long-term human exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Simulated acetaminophen overdose: pharmacokinetics and effectiveness of activated charcoal

STUDY OBJECTIVE

To determine the absorption rate of a supratherapeutic dose of acetaminophen elixir and compare the effect of activated charcoal (AC) given at different time intervals on preventing acetaminophen absorption.

DESIGN

Randomized, nonblinded, crossover controlled study.

SETTING

A certified regional poison control center.

PARTICIPANTS

Ten healthy, adult male volunteers from 21 to 39 years old.

INTERVENTIONS

Each subject received 5 g acetaminophen (elixir) on four occasions: a control phase plus 30 g of AC administered 15, 30, or 120 minutes after acetaminophen. Serum acetaminophen levels were obtained during the control phase only, and 24-hour urine collections were obtained during all four phases.

MEASUREMENTS AND MAIN RESULTS

The highest serum acetaminophen levels were measured 1.4 +/- 0.52 hours after ingestion, and absorption was 97% complete by a mean of 2.05 hours. The administration of AC at 15, 30, and 120 minutes after acetaminophen reduced urinary recovery of acetaminophen and metabolites by 48%, 44%, and 33%, respectively.

CONCLUSION

AC significantly reduces urinary recovery but not absorption of acetaminophen when administered two hours after acetaminophen elixir.

The effect of milk on ipecac-induced emesis

A prospective study at two regional poison centers was undertaken in 500 children under six years of age (mean age 2.3 y) to resolve the question of whether milk has an effect on ipecac-induced emesis. When home administration of ipecac was recommended, parents were asked to select either milk or clear fluids. The mean volume of fluid +/- standard deviation administered was 159 +/- 72 mL in the milk group and 161 +/- 77 mL in the clear fluid group (p = 0.79). There was no difference in the onset of vomiting (23.4 +/- 18.5 vs. 23.3 +/- 12.9 min, p = 0.92), number of vomiting episodes (3.5 +/- 1.9 vs. 3.4 +/- 1.8, p = 0.65), or duration of vomiting (45 +/- 73 vs. 39 +/- 54 min, p = 0.31) for the milk group compared with the clear fluid group. Side effects including lethargy and diarrhea occurred with similar frequency in both groups. The substance ingested had no effect on onset of vomiting, vomiting duration or number of vomiting episodes. These findings again demonstrate that milk does not interfere with ipecac-induced emesis.

Poisoning in the elderly. Epidemiological, clinical and management considerations

Poisoning is a significant problem in the elderly. The majority of poisonings in older people are unintentional and may result from dementia and confusion, improper use of the product, improper storage or mistaken identities. Depression is also common in the elderly and suicide attempts are more likely to be successful in this age group. The elderly patient's recuperative abilities may be inadequate as a result of numerous factors including impaired hepatic or renal function as well as chronic disease processes. General management of poisoning in the elderly parallels management of younger adults, but it is especially important to ascertain underlying medical conditions and concurrent medications. In most poisonings, activated charcoal and cathartic are sufficient. Haemodialysis or haemoperfusion may be required at lower plasma drug concentrations in elderly patients. While the specific indications for antidotes are the same for all age groups, dosage alterations and precautions may need to be considered in the elderly. Drugs most often implicated in poisonings in the elderly include psychotherapeutic drugs, cardiovascular drugs, analgesics and anti-inflammatory drugs, oral hypoglycaemics and theophylline. Cardiovascular and neurological toxicities occur with overdoses of neuroleptic drugs and, more frequently and severely, with cyclic antidepressants. Patients with pre-existing cardiovascular disease are at particular risk of worsening ischaemic heart disease and congestive heart failure. Benzodiazepines only appear to produce significant toxicity during long term administration or in combination with other CNS depressants. Digoxin can cause both chronic and acute intoxication, most seriously cardiac toxicity including severe ventricular arrhythmias, second or third degree heart block or severe refractory hyperkalaemia. Immune Fab antibody is indicated for the management of digoxin toxicity, although patients dependent on the inotropic effect of digoxin may develop heart failure after digoxin Fab antibody administration. Nitrates can cause toxicity including headache, vomiting, hypotension and tachycardia from excessive sublingual, transdermal or intravenous doses. Conduction disturbances and hypotension occur with overdoses of antihypertensive drugs; these effects are mild with angiotensin converting enzyme (ACE) inhibitors, occasionally severe with beta-blockers and of significant concern with calcium channel antagonists. The elderly commonly use aspirin and other salicylates, are more likely to develop chronic intoxications to these agents, and are more susceptible to severe complications such as pulmonary oedema. Salicylate poisoning, recognition of which is often delayed, should be considered in elderly patients with neurological abnormalities or breathing difficulties, especially in the setting of acid-base abnormalities. The clinical effects of NSAID overdose are mild and usually involve the central nervous system and gastrointestinal tract.(ABSTRACT TRUNCATED AT 400 WORDS)

Assessment of management guidelines. Acute iron ingestion

A review of 339 treated acute iron ingestions was conducted to define treatment guidelines better. According to the poison center protocol, ingestions of 20-40 mg/kg of elemental iron required only home treatment, and ingestions of greater than or equal to 40 mg/kg required hospital referral. Gastrointestinal symptoms developed in 23% of patients. There were no seriously ill patients. No serious toxicity developed in patients ingesting 40-60 mg/kg. In 199 cases in which the dose ingested was known, the mean dose was 39.5 mg/kg. The peak measured serum iron levels ranged from 12 to 539 micrograms/dl. In 129 cases with serum iron levels reported, increasing serum iron levels were associated with vomiting (p = 0.006). Of 88 patients who received deferoxamine, 14 had urine color change. Urine color change was associated with symptoms (p = 0.005) but not with iron dose or peak serum iron level. The poison center protocol was changed to home management for ingestions of 20-60 mg/kg unless significant symptoms developed and hospital referral for ingestions greater than or equal to 60 mg/kg.

Three fatal sodium azide poisonings

We report 3 cases and review the published literature on sodium azide ingestion. A 38-year-old man intentionally ingested 2 tablespoonsful of sodium azide in water and developed seizures, coma, hypotension and fatal ventricular arrhythmias within 2 hours. A 33-year-old male ingested an unknown quantity of sodium azide. In the emergency department he was unconscious and underwent immediate intubation and gastric lavage. Nitrite therapy was instituted without improvement. He remained acidotic despite bicarbonate therapy and developed hypotension which was unresponsive to pressor agents. He died approximately 8 hours after admission despite resuscitative efforts. A 52-year-old male ingested 1.5 to 2g of sodium azide and survived for 40 hours. Nitrite therapy was ineffective. The role of sodium nitrite in treating sodium azide toxicity by producing methaemoglobin which complexes with azide is discussed.

Effects of magnesium citrate and clidinium bromide on the excretion of activated charcoal in normal subjects

The efficacy of cathartics in shortening the gastrointestinal transit time of activate charcoal (AC) in the presence of drugs that alter gastrointestinal motility has not been determined. We evaluated the effects of magnesium citrate (MC) on the excretion of activated charcoal in healthy volunteers alone and with concurrent administration of the anticholinergic drug clidinium bromide. Forty subjects were randomized to clidinium bromide 5 mg or placebo capsule (PC), followed by activated charcoal 15 g and magnesium citrate or a placebo liquid (PL). The onset and duration of excretion of activated charcoal were noted. Mean onset times for activated charcoal were: group I (CB, MC) 4.5 +/- 2.1 h; group II (CB, PL) 17.0 +/- 10.0 h; group III (PC, MC) 6.3 +/- 5.8 h; and group IV (PC, PL) 20.6 +/- 8.4 h. The onset of excretion of activated charcoal was statistically different in both magnesium citrate groups as compared with the placebo liquid groups. The duration of activated charcoal in the stool was similar among the groups. The addition of clidinium bromide did not appear to affect gastrointestinal transit time. These results support previous studies of the effects of cathartics on the excretion of activated charcoal, and suggest that cathartic efficacy is not inhibited by anticholinergic drugs when used in therapeutic doses.

Lithium intoxication with acute renal failure and death

A 65-year-old female presented with only gastrointestinal symptoms eight to ten hours after an acute ingestion of an unknown amount of lithium carbonate. The serum lithium concentration was 8.5 mEq/L. Forty-eight hours postingestion she developed acute renal failure, deteriorating mental status, and cardiovascular collapse. Despite both hemodialysis and peritoneal dialysis the patient died approximately four and one-half days after ingestion. A direct nephrotoxic effect of lithium is proposed.

Clinical manifestations of toxicity in a series of 784 boric acid ingestions

A retrospective chart review was conducted at two regional poison centers to determine the clinical outcome of boric acid ingestions and to assess the relationship between serum boric acid levels and clinical presentation. A total of 784 cases were studied; all but 2 were acute ingestions. No patients developed severe manifestations of toxicity, and 88.3% were entirely asymptomatic. The most common symptoms were vomiting, abdominal pain, and diarrhea. Lethargy, headache, lightheadedness, and atypical rash were seen less frequently. Boric acid levels were obtained in 51 patients and ranged from 0 to 340 micrograms/mL. Blood levels were 70 micrograms/mL or more in 7 patients; 4 remained asymptomatic, whereas the other 3 had nausea or vomiting. Dialysis was performed in 4 of these 7 patients, only 1 of whom had symptoms (vomiting). On the basis of data from 9 patients, the mean half-life of boric acid was determined to be 13.4 hours (range, 4.0 to 27.8). Hemodialysis in 3 patients significantly shortened the half-life compared with pre- and postdialysis half-lives. Our results suggest that acute boric acid ingestions produce minimal or no toxicity and that aggressive treatment is not necessary in most patients.

In vitro study of lithium carbonate adsorption by activated charcoal

The purpose of this study was to determine whether lithium carbonate (Li2CO3) is effectively adsorbed by activated charcoal (AC). Either 0 (control), 1.5, 3.0 or 9.0 grams of AC were added to Li2CO3 (300 mg) in distilled deionized water or simulated gastric fluid USP, filtered and and the filtrate analyzed for lithium by flame photometry. Adsorption of lithium was dependent on AC concentration and pH. In water, lithium was 14.7%, 26.5% and 40.4% adsorbed at AC:Li2CO3 ratios of 5:1, 10:1 and 30:1, respectively (p less than 0.05). In simulated gastric fluid, there was no significant adsorption at any of the AC concentrations studied. Since simulated gastric fluid more closely resembles in vivo conditions, the efficacy of AC in lithium carbonate overdoses is questionable but in vivo studies are needed to confirm these findings.

In vitro study of boric acid and activated charcoal

An in-vitro study utilizing a titration assay was performed to evaluate the degree of adsorption of one gram of boric acid by 7.5 g, 15.0 g and 30.0 g of activated charcoal. The mean percentage adsorbed was 5.7 +/- 1.6% for 7.5 g of activated charcoal, 17.6 +/- 3.5% for 15.0 g of activated charcoal and 38.6 +/- 6.3% for 30.0 g of activated charcoal. Analysis of variance showed a significant difference from the control (no activated charcoal) for the 15.0 and 30.0 g samples (p less than 0.05). Although binding of boric acid by activated charcoal increased as the proportion of activated charcoal to boric acid increased, this finding is not clinically significant since the amount of activated charcoal required for 38% adsorption is 30 times the amount of boric acid ingested. Considering the toxic and potentially fatal doses of boric acid in children (5 g) and adults (20 g), doses of activated charcoal of greater than 150 g in children or 600 g in adults would be impractical for the clinical situation.

Relative toxicity of cyclic antidepressants

To compare the relative central nervous system and cardiac toxicity of amoxapine, maprotiline, and trazodone with the older tricyclic antidepressants, a three-year (1981 through 1983) retrospective review was performed on 1,313 cases involving cyclic antidepressant exposures reported to the Maryland Poison Center. Seizures were more common in the amoxapine (24.5%) and maprotiline (12.2%) groups, compared with either the tricyclic antidepressants (3.0%) or trazodone (0%) (P less than .01). A higher incidence of seizures also was observed in desipramine ingestors (17.9%) compared with other tricyclic antidepressants. No significant differences in the incidence of central nervous system depression or cardiotoxicity was found between the groups. These findings support reports of an increased incidence of seizures in overdoses of amoxapine and maprotiline, but do not substantiate claims of less cardiotoxicity.

Ipecac administration in children younger than 1 year of age

The efficacy of ipecac syrup in the induction of emesis and safety of its administration was studied in 105 poison-exposed infants 6 through 11 months of age (study subjects) and compared prospectively with 302 poison-exposed infants and children 12 through 35 months of age who served as age controls. Of the 105 study subjects 101 (96.2%) vomited. The failure of ipecac to induce emesis in six patients (four of 105 study subjects two of 302 age control subjects) is comparable with ipecac failure rates reported elsewhere. The frequency of side effects caused by ipecac syrup did not differ between study and control subjects. There were no serious medical complications resulting from the administration of ipecac syrup. When not readily available at home, ipecac administration was delayed an additional 21.8 minutes if obtained from a pharmacy and 38.4 minutes if obtained from an emergency department. Because of the time delay and the increased health care cost, home rather than emergency department administration of ipecac should be advised. These data demonstrate that ipecac syrup effectively induces emesis and is safe for home administration to poisoned infants 6 to 11 months old.

Public awareness survey: the Maryland Poison Center and Mr. Yuk, 1981 and 1975

A telephone survey of residents of metropolitan Baltimore was conducted in 1981 to assess awareness of the Maryland Poison Center and a program based on the Mr. Yuk poisoning warning symbol. The results of 280 telephone interviews are compared with a similar survey conducted 6 years earlier by the Maryland Poison Center. When faced with a harmful exposure, the most common response in the 1981 survey (32.9 percent) was to call the poison center. That response was only the fourth most frequent answer (14.5 percent) in the 1975 survey. Calling a physician or taking the person to a physician was the most frequent response in 1975 (29.5 percent) but only the fourth most frequent in 1981 (15.0 percent). Of the respondents who would call a poison center, 55.7 percent in the 1981 survey knew the center's telephone number or had ready access to it. Public awareness of Mr. Yuk remained at approximately 60 percent in both surveys. Persons familiar with the warning symbol in the latest survey were three times as likely to call the poison center as those who were not aware of it.

Azalea toxicity: an overrated problem?

One-hundred-and-fifty-two azalea ingestions reported to two regional poison centers over a three year period are reviewed. Twenty-eight exposures were the result of sucking nectar from the flower; the remainder involved ingestion of leaves or flowers. Nine patients developed symptoms, but these were minor or probably unrelated in eight. A single patient was significantly symptomatic, experiencing repeated vomiting and transient hypertension. Emergency department treatment was rendered in 9.2% of patients, and hospital admission for less than 24 hours was required in only one case. Ingestion of moderate amounts of azalea pose little toxic hazard.

Ipecac use in the elderly: the unanswered question

An elderly patient experienced an intracerebral bleed temporally related to the administration of syrup of ipecac. The experience of the certified regional poison centers of the American Association of Poison Control Centers shows that this is an uncommon event. The use and safety of ipecac in the elderly has not been adequately addressed in the past.

Continuous naloxone infusion in pediatric narcotic overdose

A 31-month-old girl required constant intravenous (IV) infusion of naloxone hydrochloride to treat codeine-induced respiratory and CNS depression. The infusion rate was 0.4 mg/hr (27 micrograms/kg/hr) over nine hours, without apparent side effects or evidence of toxic effects, for a total naloxone hydrochloride dose of 4.1 mg (280 micrograms/kg). Constant naloxone hydrochloride infusion at an initial rate of 0.4 mg/hr in pediatric narcotic poisoning should be considered if the patient responds inadequately to an initial 0.01-mg/kg bolus, requires repeated administration to reverse narcotic-induced effects, or has ingested long-acting agents. Continuous IV naloxone infusion is a convenient, safe, and effective method to treat narcotic overdose.

Jimsonweed intoxication in adolescents and young adults

Seventy-three jimsonweed exposures reported to a regional poison center over a five-year period were reviewed. The ingestors' mean age was 17.3 years (range, 11 to 28 years). The most common route of exposure was oral, and the circumstance was drug abuse or experimentation in the majority of the cases. Although 11 callers remained at home, 59 required medical care in an emergency department or were admitted to the hospital. Treatment consisted of gastrointestinal decontamination, supportive care, and physostigmine salicylate administration. Almost 40% of the medically treated patients received physostigmine for severe hallucinations. One of the 59 medically treated patients had seizures develop. Calls to the poison center regarding jimsonweed differed from other calls in several respects. Jimsonweed abuse is a potentially serious form of substance abuse in adolescents and young adults.

Warning labels. A source of toxicity information for parents

The Hazardous Substances Act specifies that warning labels for household products contain specific signal words. This study was designed to determine whether this warning label format provides enough information for parents to accurately assess product toxicity. One hundred forty-two parents from two different sites (community health clinic, private pediatrician's office) were asked to rate the toxicity of four common household products (Crystal Drano, Lysol Basin/Tub and Tile Cleaner, Clorox Bleach, Tempera Poster Paint) and four imaginary products based on the warning labels found on them. Parents had a fairly accurate perception of the toxicity of products and the toxicity to be anticipated based on the warning label. There was considerable variability in response for products which were less toxic or nontoxic. Confusion was noted regarding the meaning of the term nontoxic.

Poison information providers: an assessment of proficiency

An analysis of the results of a national certification examination for poison information specialists administered by the American Association of Poison Control Centers is presented. The failure rate in nonregional centers was more than double that in regional centers, and presents a strong argument for regionalization. Poison information specialists with prior training as pharmacists or registered nurses performed significantly better than those who were high school or college graduates in other fields, emergency medical technicians, or licensed practical nurses. Poison information specialists in centers receiving more than 15,000 calls each year had significantly higher scores. Individual total work experience also had a small but significant correlation with score. The mean score for emergency physicians serving as a control group was 57.0% compared with 77.1% for poison information specialists. The data suggest that telephone consultations for poison emergencies are done best by those who do them on a specialized full-time basis. Calls should be referred to the appropriate regional poison control center.

Poison prevention in the elderly

Poison exposures in the elderly are largely unintentional and, therefore, amenable to prevention techniques. Based on an analysis of the major causes of unintentional exposures in persons age 60 years and older, injury control strategies are applied to poisoning. These strategies address pre-event, event, and post-event phases. Ideas for specific changes to protect the elderly, especially in the areas of labeling and packaging, are presented.