Clinical characteristics and outcome of toxicity from Amanita mushroom poisoning

Satariya Trakulsrichai,1,2 Charuwan Sriapha,2 Achara Tongpoo,2 Umaporn Udomsubpayakul,3 Sunun Wongvisavakorn,2 Sahaphume Srisuma,2,4 Winai Wananukul2,4 1Department of Emergency Medicine, 2Ramthibodi Poison Center, 3Section for Clinical Epidemiology and Biostatistics, Research Center, 4Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Objective: To describe and analyze the clinical characteristics and outcome of amatoxin poisoning cases.Methods: We performed a retrospective cohort study of amatoxin poisoning cases from ­Ramathibodi Poison Center Toxic Exposure Surveillance System, from May 2013 to August 2015.Results: There were 30 consultations with a total of 55 poisoning cases. Most cases were male and from the north-east region. Hepatitis, acute kidney injury, jaundice, and coagulopathy accounted for 74%, 46.3%, 44.7%, and 52.8% of the cases, respectively. Almost all of the patients were admitted to the hospital, and the median duration of hospital stay was found to be 4 days. Mortality rate was found to be 27.3%. Most patients (73%) received the treatment including multiple-dose activated charcoal (67.5%), intravenous N-acetylcysteine (87.5%), and benzylpenicillin (45%). In 60% of the cases, the treatment was initiated within 24 h after eating mushrooms. Exchange transfusion and liver transplantation were performed in one severe case. However, this patient died eventually. Because intravenous silybinin is not available in Thailand during the study period, 8 patients received oral silymarin instead. All 8 patients had hepatitis and were treated with high dosage of oral silymarin (5 patients with 4.48 g/day, 2 patients with 1.68 g/day, and 1 patient with 1.4 g/day) for a couple of days. One of these patients died as she received treatment very late; she was treated with silymarin at 1.68 g/day dosage. Thus, the fatality in oral silymarin treatment group was 12.5%. We performed the analysis between the dead and survival groups. We found that in hepatitis, initial and maximum serum aspartate transaminase, initial and maximum serum alanine transaminase, and acute kidney injury were significantly different between the two groups.Conclusion: Amanita mushroom poisoning caused high fatalities. Serum transaminase and creatinine were the factors associated with death. Treatment with oral high dose silymarin should be investigated further as one of the principal therapies in amatoxin poisoning. Keywords: amatoxin, clinical characteristic, outcome, treatment, silymari

Krait envenomation in Thailand

Achara Tongpoo,1 Charuwan Sriapha,1 Aimon Pradoo,1 Umaporn Udomsubpayakul,2 Sahaphume Srisuma,1,3 Winai Wananukul,1,3 Satariya Trakulsrichai1,4 1Ramthibodi Poison Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; 2Section for Clinical Epidemiology and Biostatistics, Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; 3Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; 4Department of Emergency Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Purpose: Three species in the genus Bungarus inhabit Thailand. Among these, Bungarus candidus (Malayan krait) is the most common and deadliest. Currently, the clinical manifestations of patients envenomed by kraits, especially Bungarus fasciatus (banded krait), have not been thoroughly investigated. This study was performed to elucidate the clinical manifestations and outcomes of patients bitten by kraits in Thailand. Materials and methods: The data of krait envenomation cases that occurred during a 9-year period were obtained from the Ramathibodi Poison Center Toxic Exposure Surveillance System and retrospectively analyzed. Results: In total, 78 cases of krait envenomation were included. Most patients were male (59.0%) and the median age was 28 years. All had minimal local effects. The median duration from the bite to the onset of neurological manifestations was 3 hours (range, 0.5–8 hours). Besides neurological effects, the patients also developed high blood pressure (67.4%), tachycardia (61.7%), hypokalemia (55.3%), and hyponatremia (17.6%). Severe hyponatremia (<120 mEq/L) was noted in four pediatric patients. Other clinical manifestations were bradycardia, abdominal pain, and rhabdomyolysis. The mortality rate was 6.4%, and all deaths occurred from B. candidus bites. Eighty-six percent of patients received antivenom. Most patients (75.6%) were intubated and underwent assisted ventilation for a median of 6 days (range, 1–37 days). The median length of hospital stay was 7 days. Some patients developed complications during hospitalization; the most common was pneumonia. These in-hospital complications were significantly associated with death. Conclusion: Although krait bites caused only minimal local effects, the mortality rate was still high, particularly from Malayan krait bites. Besides neurological effects, other clinical manifestations were high blood pressure, tachycardia, hypokalemia, and hyponatremia. Thus, vital signs and electrolytes should be frequently and closely monitored in these patients. Apart from antivenom treatment, adequate supportive care including management of complications might help to decrease the mortality rate. Keywords: snake bite, Bungarus, Malayan krait, banded krait, clinical manifestation, outcom

Pharmacokinetics of mitragynine in man

Satariya Trakulsrichai,1,2 Korbtham Sathirakul,3,4 Saranya Auparakkitanon,5 Jatupon Krongvorakul,5 Jetjamnong Sueajai,5 Nantida Noumjad,5 Chonlaphat Sukasem,5 Winai Wananukul2,6 1Department of Emergency Medicine, Faculty of Medicine Ramathibodi Hospital, 2Ramathibodi Poison Center, Faculty of Medicine Ramathibodi Hospital, 3Department of Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand; 4Center for Drug Research Discovery and Development, Thammasat Univerisity, Prathumthani, Thailand; 5Department of Pathology, Faculty of Medicine Ramathibodi Hospital, 6Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Background: Kratom, known botanically as Mitragyna speciosa (Korth.), is an indigenous tree in Southeast Asia. Kratom is currently easily available worldwide via special shops and the Internet to use as a drug of abuse, opioid alternative, or pain killer. So far, the pharmacokinetics of this plant has been studied only in animals, and there is no such study in humans. The major abundant active alkaloid in Kratom, mitragynine, is one of the promising new chemical substances to be developed as a new drug. The aim of this study was to examine the pharmacokinetics of mitragynine and assess the linearity in pharmacokinetics in chronic users.Methods: Since Kratom is illegal in Thailand, studies in healthy subjects would be unethical. We therefore conducted a prospective study by enrolling ten chronic, regular, healthy users. We adjusted the steady state in each subject by giving a known amount of Kratom tea for 7 days before commencement of the experiment. We admitted and gave different oral doses to subjects to confirm linearity in pharmacokinetics. The mitragynine blood concentrations at 17 times points and the urine concentrations during the 24-hour period were collected and measured by liquid chromatography-tandem mass spectrometry method. Results: Ten male subjects completed the study without adverse reactions. The median duration of abuse was 1.75 years. We analyzed one subject separately due to the abnormal behavior of blood concentration. From data of nine subjects, the pharmacokinetic parameters established were time to reach the maximum plasma concentration (0.83±0.35 hour), terminal half-life (23.24±16.07 hours), and the apparent volume of distribution (38.04±24.32 L/kg). The urine excretion of unchanged form was 0.14%. The pharmacokinetics were observed to be oral two-compartment model. Conclusion: This was the first pharmacokinetic study in humans, which demonstrated linearity and was consistent with the oral two-compartment model with a terminal half-life of about 1 day. The pharmacokinetic linearity and parameters reported are necessary pharmacological information of Kratom, and there is a possibility for it to be developed medically as a pain killer or better opioid substitute in the future. Keywords: kratom, human, pharmacokinetic