Gastric lavage is one of gastrointestinal decontamination methods which have been controversial in the clinical toxicology field for a long time. Expert groups of American and European clinical toxicologists have published the position papers regarding gastric lavage three times since 1997. They recommended that gastric lavage should not be used as a routine procedure in the management of acute intoxication, because they thought that there is no certain evidence of improving clinical outcome by its use. However, the studies they reviewed were not well-controlled randomized trials, which cannot be conducted in the clinical toxicology field due to variability of patients and ethical problems. Therefore, the results from these studies should be interpreted with caution. They also insisted that gastric lavage can be undertaken within 60 minutes of ingestion. The limitation of one hour after ingestion is too arbitrary and may cause a lot of misunderstanding. Formation of pharmacobezoar or gastric hypomotility after ingestion may significantly delay the gastric emptying time so that gastric lavage can be useful even after several hours or more in case of highly toxic substances or severe intoxication. Furthermore, as there are a number of serious intoxication by toxic pesticides with large amount in suicidal attempts in Korea, it seems that gastric lavage may be used more frequently in Korea than in Western countries. When deciding whether or not to use gastric lavage, all the indications, contraindications, and possible adverse effects should be taken into account on the basis of risk-benefit analysis. If the procedure is decided to be done, it should only be performed by well-trained experts.

Purpose: Antidotes for toxicological emergencies can be life-saving. However, there is no nationwide stocking and delivery system for emergency antidotes in Korea. We report on a two-year experience of a nationwide stocking and delivery trial for emergency antidotes at emergency departments in Korea. Methods: An expert panel of clinical toxicologists reviewed and made a list of 15 stocked antidote. These antidotes were purchased or imported from other countries and delivered from 14 antidote stocking hospitals nationwide 24 hours per day, seven days per week. Results: From August 1, 2011 to April 30, 2013, 177 patients with acute poisoning, with a median age of 48.5 years, were administered emergency antidotes. The causes of poisoning were intentional in 52.0% and 88.0% were intentional as a suicide attempt. Regarding clinical severity, using the poisoning severity score, 40.7% of patients had severe to fatal poisoning and 39.0% had moderate poisoning according to clinical severity. The most frequent presenting symptom was neurologic deficit, such as altered mentality (62.7%). alerted mentality (62.7%). Emergency antidotes were administered as follows: methylene blue (49 cases), flumazenil (31), N-acetylcysteine (25), glucagon (17), 100% ethanol (15), cyanide antidote kit (12), anti-venin immunoglobulin (5), pyridoxine (4), hydroxocobalamine (2), and deferoxamine (1). The median time interval from antidote request to delivery at the patient's bedside was 95 minutes (interquartile range 58.8-125.8). Conclusion: Findings of this study demonstrated the possibility of successful operation of the nationwide system of emergency antidotes stocking and delivery in Korea.

Dextromethorphan and chlorpeniramine are common ingredients of over-the-counter (OTC) cough pills. They are known to be safe when used alone, however, combination with other serotonergic drugs or use of an overdose can cause serotonergic toxicity. We report on a 43-year-old male and a 57-year-old female who ingested an overdose of antitussive drugs containing dextromethorphan and chlorpeniramine. They commonly presented with altered mentality and hyperreflexia on both upper and lower extremities. After conservative therapies, they were discharged with alert mentality. These cases are meaningful in that there are few cases of serotonin syndrome with an overdose of a combination of dextromethorphan and chlorpeniramine. Careful use with medication counseling for OTC cough pills is needed in order to prevent overdose of these ingredients.

Zoletil is a non-opioid, non-barbiturate animal anesthetic and proprietary combination of two drugs, a dissociative anesthetic drug, tiletamine, with the benzodiazepine anxiolytic drug, zolazepam. Zoletil has greater potency than ketamine. Zoletil is abused for recreational purposes, especially by people with easy access to medicine. However, in Korea, it is available over-the-counter. Here we report on a case of an 83-year-old woman who received injection of seven vials of "Zoletil 50" by her daughter and presented with an altered mental change. Her mental state was stupor and vital sign was hypotension, bradycardia. Her blood tests indicated metabolic and respiratory acidosis and hyperkalemia. She was treated with intravenous naloxone and flumazenil but was not responsive. She was admitted to the ICU and treated with supportive therapy. Her mental state showed transient recovery, however, her clinical manifestation worsened and she expired.

A 66-year-old male with chronic alcoholism presented with tremor, gait disturbance, memory impairment, insomnia, decreased appetite, and confusion. The patient had been taking lithium daily for treatment of bipolar disorder. Brain CT showed no specific abnormality, and serum lithium and ammonia levels were 3.63 mEq/L (therapeutic range, 0.6~1.2 mEq/L) and $85{\mu}g/dL$ (reference range: $19{\sim}54{\mu}g/dL$), respectively. Therefore, the initial differential diagnosis included chronic lithium intoxication, hepatic encephalopathy, Wernicke encephalopathy, or alcohol withdrawal syndrome. Even with the provision of adequate hydration, the patient's neurologic status did not show improvement, so that lactulose enema, thiamine replacement, and continuous venovenous hemodiafiltration (CVVHDF) were started on the third admission day. By the fifth admission day he had made a rapid neurologic recovery, and was discharged on the 20th admission day. Therefore, CVVHDF might be a treatment for patients with chronic lithium intoxication, because, even if serum lithium concentration is normal, lithium concentration in the brain may be different from that of the serum.

Acute organophosphate intoxication is important because of its high morbidity and mortality. The mortality is still high despite the use of atropine as specific antidotal therapy and oximes for reactivation of acetylcholinesterase. Inhibition of acetylcholinesterase by organophosphate can cause acute parasympathetic system dysfunction, muscle weakness, seizure, coma, and respiratory failure. Acute alteration in conscious state or a coma, which may occur following organophosphate intoxication, is an indication of severe intoxication and poorer prognosis. This acute decline in conscious state often reverses when the cholinergic crisis settles; however, it may be prolonged in some patients. We report on a case of a 60-year-old male who showed prolonged decline in conscious state due to of Central Nervous System (CNS) toxicity after a suicide attempt with organophosphate.

Ethylene glycol poisoning is treated mainly by alcohol dehydrogenase inhibition therapy and hemodialysis. Early recognition and initiation of treatment is important because toxic metabolites increase over time by hepatic metabolism; however, there is no confirmative diagnostic tool in our clinical setting. Therefore, diagnosis is dependent on history, high anion gap acidosis, high osmolal gap, etc.. Diagnosis and treatment are delayed in cases where history taking is not possible, such as a mental changed patient. Authors report on two cases of ethylene glycol poisoning by contrasting clinical outcomes, demonstrating the importance of early diagnosis and treatment for achievement of a good outcome.

Following are brief statements about the delayed encephalopathy of a patient who recovered without disturbance of consciousness after acute carbon monoxide poisoning. A 72-year-old male was found without consciousness at home and then visited the ER center. Later we learned that the patient was using briquettes as a household heating source. Blood carbon monoxide hemoglobin level was 17.5%. As carbon monoxide poisoning was uncertain after the first interview with the patient, hyperbaric oxygen therapy was not administered at the early stage. After supplying 100% oxygen, the patient recovered consciousness, however, the strength of the lower limb muscle had decreased to class II. The patient showed continued weakening of the lower limb muscle and an increase of CPK; therefore, he was diagnosed as carbon monoxide intoxication and rhabdomyolysis and then admitted to the intensive care unit (ICU) for conservative treatment. During the hospitalization period, continued weakening of the lower limb muscle was observed and he was diagnosed as myopathy after EMG/MCV. However, he suddenly showed altered mentality on the 20th day of hospitalization, and underwent brain MRI. T2 weighted MRI showed typically high signal intensity of both globus pallidus and periventricular white matter; therefore, he was diagnosed as delayed carbon monoxide encephalopathy. This case showed delayed encephalopathy accompanied by rhabdomyolysis and myopathy of a patient who recovered without disturbance of consciousness.

Potamotrygon motoro, also known as the Marble motoro, is a potamodromous freshwater ray native to the basins of the Amazon River. Marble motoros were introduced to South Korea in the 2000s, and, because they are easy to raise, were sold as aquarium fish. The aim of this report is to illustrate a new case involving envenomation by a Marble motoro. A 35-year-old commercial aquarium assistant came to the hospital after being pricked by a Marble motoro. The clinical picture in this case showed acute local pain with minimal systemic manifestations. This patient recovered after receiving symptomatic treatment and wound care. This case of envenomation accentuates the potential for injury among people coming in contact with a venomous Marble motoro.

Fentanyl, a synthetic, highly selective opioid ${\mu}$-receptor agonist, is 50 to 100 times more potent than morphine. The low molecular weight, high potency, great transdermal permeation rate and lipid solubility of fentanyl make it very suitable for transdermal administration. Durogesic is a novel matrix transdermal system providing continuous systemic delivery of fentanyl. In recently, there are many reports that misused or overused fentanyl transdermal patches result in severe intoxication of fentanyl. We present a case of fentanyl toxicity with misused durogesic transdermal patch and discuss the safe and appropriate application of the patches. In conclusion, fentanyl patches should be used in opioid tolerant patients and prescribed at the lowest possible dose and titrated upward as needed. All patients and their caregivers should be educated safe application of fentanyl patches and advised to avoid exposing the patches application site to direct external heat sources, such as heating pads, or electric blankets, heat lamps, sauna, hot tubs, and others. In addition, concomittant medications that affect fentanyl's metabolism should be avoided.