Risk factors for complications of drug-induced seizures

The purpose of this study is to determine clinical factors associated with complications of drug-induced seizures. This prospective observational study was conducted at an American Association of Poison Control Centers-certified regional poison control center (PCC) over a 1-year period. All consecutive cases reported to a PCC involving seizures were forwarded to investigators, who obtained standardized information including the specific drug or medication exposure, dose, reason for exposure, vital signs, laboratory data, treatment, and outcome. Patients were monitored by daily telephone follow-up until death or discharge. Subjects were excluded if the seizure was deemed to be unrelated to exposure. Odds ratios were used to analyze variables for associations with admission to the hospital for >72 h, endotracheal intubation, status epilepticus, anoxic brain injury, or death. One hundred twenty-one cases met inclusion criteria. Sixty-three (52%) were male, and the mean age was 30 (SD14) years. Common exposures included: antidepressants (33%), stimulants (15%), and anticholinergics (10%). One hundred and three (85%) of the exposures were intentional, of which 74 were suicide attempts and 16 were drug abuse or misuse. Forty-nine (40%) patients required endotracheal intubation, 12(10%) had status epilepticus, 50(41%) were hospitalized for more than 72 h, and one patient died. Median hospital stay was 3 days. Variables significantly associated with complications included stimulant exposure (odds ratios, OR = 11 [95% confidence intervals (CI) 1.9–52]), suicide attempt (OR = 2.2 [95% CI 1.02–4.7]), initial hypotension (OR = 11.2 [95% CI 1.4–89.3]), admission glucose >130 mg/dL (OR = 5.4 [95% CI 1.6–18.1]), and admission HCO₃ < 20 mEq/L (OR = 4.0 [95% CI 1.4–11.3]). Significant clinical factors associated with complications of drug-related seizures include stimulant exposure, suicide attempt, initial hypotension, and admission acidosis or hyperglycemia.

Mechanisms of respiratory insufficiency induced by methadone overdose in rats

Methadone may cause respiratory depression. We aimed to understand methadone-related effects on ventilation as well as each opioid-receptor (OR) role. We studied the respiratory effects of intraperitoneal methadone at 1.5, 5, and 15 mg/kg (corresponding to 80% of the lethal dose-50%) in rats using arterial blood gases and plethysmography. OR antagonists, including intravenous 10 mg/kg-naloxonazine at 5 minutes (mu-OR antagonist), subcutaneous 30 mg/kg-naloxonazine at 24 hours (micro1-OR antagonist), 3 mg/kg-naltrindole at 45 minutes (delta-OR antagonist) and 5 mg/kg-Nor-binaltorphimine at 6 hours (kappa-OR antagonist) were pre-administered. Plasma concentrations of methadone enantiomers were measured using high-performance liquid chromatography coupled to mass-spectrometry. Methadone dose-dependent inspiratory time (T(I)) increase tended to be linear. Respiratory depression was observed only at 15 mg/kg and characterized by an increase in expiratory time (T(E)) resulting in hypoxemia and respiratory acidosis. Intravenous naloxonazine completely reversed all methadone-related effects on ventilation, while subcutaneous naloxonazine reduced its effects on pH (P < 0.05), PaCO(2) (P < 0.01) and T(E) (P < 0.001) but only partially on T(I) (P < 0.001). Naltrindole reduced methadone-related effects on T(E) (P < 0.001). Nor-binaltorphimine increased methadone-related effects on pH and PaO(2) (P < 0.05) Respiratory effects as a function of plasma R-methadone concentrations showed a decrease in PaO(2) (EC(50): 1.14 microg/ml) at lower concentrations than those necessary for PaCO(2) increase (EC(50): 3.35 microg/ml). Similarly, increased T(I) (EC(50): 0.501 microg/ml) was obtained at lower concentrations than those for T(E) (EC(50): 4.83 microg/ml). Methadone-induced hypoxemia is caused by mu-ORs and modulated by kappa-ORs. Additionally, methadone-induced increase in T(E) is caused by mu1- and delta-opioid receptors while increase in T(I) is caused by mu-ORs.

Pediatric Case Report of Topiramate Toxicity

BACKGROUND

Topiramate is an FDA-approved second generation antiepileptic drug with actions on voltage-dependent sodium and calcium channels and GABA and excitatory amino acid receptors. There has only been one prior pediatric case report of topiramate toxicity. We report a 33-month-old girl with persisting neurologic symptoms after acute ingestion of topiramate.

CASE REPORT

A 33-month-old girl was found at her sitter'shouse with a bottle of topiramate (100-mg tablets). She presented to the emergency department 3 days post-ingestion. The child appeared confused and was only able to crawl. At one point, she looked directly at mother and asked, "Where is my mommy?" She had visual hallucinations and screamed while pointing to objects on the wall. Neurologic exam was notable for the slurred speech and severe ataxia. All laboratory testing, urine chemical dependency screen, CSF, chest X-ray, head CT, and EEG showed no abnormalities. Topiramate level on the third day post-ingestion was 9.4 mcg/mL, and 4.2 mcg/mL on the fourth day. Patient became oriented to family and regained normal gait on the fourth day. Her slurred speech persisted until the sixth day after ingestion.

CONCLUSION

Topiramate is an anti-epileptic drug with multifactorial mechanisms of action not entirely understood. We report here a 33-month-old girl with prolonged neurologic symptoms including hallucination, slurred speech, and severe ataxia after acute topiramate ingestion. This is the first pediatric case report of hallucination and prolonged neurologic symptoms with acute topiramate ingestion.

Too toxic

Firm up on the facts and considerations associated with acetaminophen toxicity.

Pediatric montelukast ingestions reported to Texas poison control centers, 2000-2005

Limited information exists on the toxicity of pediatric ingestions of the drug montelukast used in the treatment of chronic asthma. All ingestions of montelukast involving children age 0-5 yr reported to Texas poison control centers during 2000-2005 were retrieved. For a subset of cases where the final medical outcome and dose in milligrams or milligrams per kilogram were known, the pattern of exposures by final medical outcome and management site was evaluated. There was a total of 3698 cases. Of those cases with a known final medical outcome and dose, the mean dose in milligrams was 42.5 mg (range 0.4-536 mg) and the mean dose in milligrams per kilogram was 3.36 mg/kg (range 0.18-33.71 mg/kg). The final medical outcome was no observed effect in 95% of the cases and minor effect in the remainder of the cases. The patient was managed on site in 80% of the cases. The proportion of cases with a minor effect increased from 5% for ingested dose of < or = 100 mg to 10% for > 100 mg but was 5% for dose < or = 5 mg/kg and > 5 mg/kg. The proportion of cases managed with health care facility involvement increased from 15% for ingested dose of < or = 100 mg to 56% for > 100 mg and rose from 10% for dose < or = 5 mg/kg to 47% for dose > 5 mg/kg. Pediatric montelukast ingestions of doses up to 536 mg or 33.71 mg/kg do not appear likely to result in serious adverse effects and usually can be managed at home.

Emergency department management of the salicylate-poisoned patient

Salicylate toxicity continues to be encountered commonly in emergency medicine. This article portrays the signs and symptoms of salicylate toxicity, reviews the erratic absorption and elimination kinetics, describes the devastating physiologic effects of overdose, and illustrates the potentially subtle manifestations of chronic aspirin toxicity.

Atypical antipsychotics and newer antidepressants

Atypical antipsychotics and newer antidepressants are commonly prescribed medications responsible for tens of thousands of adverse drug exposures each year. The emergency medicine physician should have a basic understanding of the pharmacology and toxicity of these agents. This knowledge is crucial to providing proper care and timely management of patients presenting with adverse drug effects from exposure to atypical antipsychotics and newer antidepressants.

Lamotrigine overdose in a child

The purpose of this article is to describe an unusual presentation of lamotrigine toxicity in an epileptic child treated on a lower than previously reported dosage. This is a case description of a 5-year-old epileptic girl on lamotrigine monotherapy, which caused toxicity. The child presented with ataxia, drowsiness, and acute confusion after ingesting 500 mg (25 mg/kg/d) in two 250-mg doses 12 hours apart. This was followed by vomiting and seizure exacerbation. Discontinuing lamotrigine, intravenous fluids and observation were the mainstays of therapy. Until now, the reported minimum dose of lamotrigine causing toxicity was 800 mg. In this patient, toxic manifestation occurred after the initial 250 mg. This case report demonstrates the low safety margin in children treated with lamotrigine.

Carbamazepine poisoning managed with haemodialysis and haemoperfusion in three adolescents

Carbamazepine is a widely used antiepileptic agent. Accidental or suicidal overdose in children is not uncommon. Acute toxicity is associated with seizures, coma, arrhythmias and death in severe cases. Here we report three adolescents with carbamzepine overdose, two managed with standard low-flux haemodialysis and one with charcoal haemoperfusion. Our report emphasizes that haemodialysis might be a cheaper and easier alternative for carbamazepine overdose in milder cases, with fewer side-effects than haemoperfusion.

Onset of symptoms after methadone overdose

BACKGROUND

Methadone ingestion may cause delayed coma and require naloxone infusion. Few studies exist regarding the time development of symptoms following methadone overdose in adults.

METHODS

After a brief training period, reviewers who were blinded to the purpose of the study completed a standardized data collection sheet. Two consecutive years of poison center patient encounters were reviewed. Age, outcomes, coingestions, vital signs, clinical manifestations, hospital admissions, and mortality were abstracted. Data were analyzed using descriptive statistics. The first reviewer was designated to extract the data. The second reviewer conducted a review of 20% of all the charts for a kappa value to be calculated.

RESULTS

In total, 44 cases of isolated methadone overdose in patients older than 18 years were identified. A mean age of 32.5 (18-58) years and a mean presumed ingestion of 106 mg of methadone was calculated. Of the 44 patients, 32 received naloxone for symptoms consistent with opiate toxicity. All symptoms occurred within 9 hours of methadone ingestion, with a mean symptom onset of 3.2 hours. All patients had resolution of symptoms within 24 hours. No deaths were recorded. The kappa score for interreviewer reliability was 0.69, with a 95% confidence interval of 0.58 to 0.73.

LIMITATIONS

This was a retrospective study that was limited by patient history.

CONCLUSION

Acute methadone toxicity typically results in symptoms within 9 hours of ingestion.

Are one or two dangerous? Quinine and quinidine exposure in toddlers

Quinine and quinidine have been cited as drugs that may cause significant morbidity and mortality in toddlers who ingest one or two pills. The use of both of these drugs has declined in the United States since the 1980s. A review of the literature and Poison Control data reveals that large quinine and quinidine ingestions, although rare in this country, may lead to severe toxicity and death related to cardiovascular and neurological effects in both children and adults. Although the majority of cases of quinine and quinidine toxicity in toddlers occur after ingestions of more than two pills, a single report each of severe toxicity after the equivalent of an ingestion of two pills or less by a toddler exists for both quinine and quinidine. Although the risk to the toddler exposed to one or two tablets seems to be small, triage to an Emergency Department is warranted after quinidine ingestion of any amount and after quinine ingestion that exceeds the age-appropriate therapeutic dose.

Severe botulism after focal injection of botulinum toxin

We report a 34-year-old woman who developed clinical botulism after the cosmetic use of an unapproved botulinum toxin type A. Electrophysiologic findings demonstrated complete denervation with complete electrical silence. She had a lengthy recovery but was able to ambulate by discharge.

Is phenytoin administration safe in a hypothermic child?

A male neonate with a Chiari malformation and a leaking myelomeningocoele underwent ventriculoperitoneal shunt insertion followed by repair of myelomeningocoele. During anaesthesia and surgery, he inadvertently became moderately hypothermic. Intravenous phenytoin was administered during the later part of the surgery for seizure prophylaxis. Following phenytoin administration, the patient developed acute severe bradycardia, refractory to atropine and adrenaline. The cardiac depressant actions of phenytoin and hypothermia can be additive. Administration of phenytoin in the presence of hypothermia may lead to an adverse cardiac event in children. As phenytoin is a commonly used drug, clinicians need to be aware of this interaction.

Medical management of adolescent drug overdoses

This article outlines the current clinical approach to poisonings in the adolescent age group. Management issues are presented for several specific substances frequently abused by this population. The purpose of such a review is to stimulate self-education in the practitioner. A secondary goal is to promote awareness of the various manifestations of substance abuse problems to facilitate recognition and referral. Adolescence is often a critical point for effective intervention and prevention on the road from use to addiction. Long-term survival may depend more on substance use rehabilitation than on the initial medical management.

Serial Bispectral index scores in patients undergoing observation for sedative overdose in the emergency department

STUDY OBJECTIVE

Many patients who overdose on sedatives experience a declining mental status and eventually require endotracheal intubation. The goal of this study was to determine if serial bedside Bispectral index (BIS) scores monitoring can be used to detect the eventual need for intubation in overdosed patients who are undergoing observation in the ED.

METHODS

This was a prospective, observational study of a convenience sample of patients who presented to the Hennepin County Medical Center ED between June and November 2002. Patients being treated and observed for a suspected sedative ingestion were eligible. Upon presentation, a Bispectral electroencephalographic probe was applied to the patient's forehead, and a BIS score was recorded at 0 and 20 minutes. The Altered Mental Status scale was used to describe the patient's clinical status. Data were collected by trained research assistants. Data are described with descriptive statistics. The mean changes in BIS score between patients who did and did not require intubation are compared with t tests, and the outcome of patients with stable vs declining BIS scores were compared with chi(2) tests.

RESULTS

Seventy-six patients were enrolled. The mean initial BIS score was 83.9 (95% CI, 79.7-88.1; range, 9-99). The mean change in BIS scores during the 20-minute observation period for the patients who required intubation was -13.5 (95% CI, -30.2 to 3.2) and was +6.7 (95% CI, 3.3-10.1) for those who were not intubated. Sixteen patients had an initial BIS score below 70. Of these patients, 6 were intubated. All intubations occurred during the 20 minutes, and this group had a mean initial BIS of 47.2 (95% CI, 35.6-58.8). The 10 patients with an initial BIS below 70 who were not intubated had a mean increase in BIS score of 23.3 (95% CI, 11.7-33.9) during the 20 minutes. Of the 60 patients whose first BIS score was above 70, 5 were eventually intubated during their ED treatment. The mean change in BIS was -36.4 (95% CI, -18.7 to -54.1) for the intubated patients vs +7.9 (95% CI, 4.4-11.3) for nonintubated patients during the first 20 minutes.

CONCLUSION

The overdosed patients who required intubation during their ED treatment experienced a mean decrease in BIS during the first 20 minutes, compared with those who did not. Bispectral index scores monitoring may prove useful for earlier ED treatment and decision making regarding sedative overdose patients.