Cyanide poisoning in Thailand before and after establishment of the National Antidote Project.

CONTEXT: Antidote shortage is a global problem. In Thailand, the National Antidote Project (NAP) has operated since November 2010 to manage the national antidote stockpile, educate the healthcare providers on appropriate antidote use, and evaluate antidote usage. OBJECTIVE: To evaluate the effect of NAP implementation on mortality rate and antidote use in cyanide poisoning cases arising from ingestion of cyanide or cyanogenic glycoside. METHODS: This is a retrospective cohort of poisoning cases involving cyanide or cyanogenic glycoside ingestion reported to Ramathibodi Poison Center from 1 January 2007 to 31 December 2015. Mortality rate, antidote use, and appropriateness of antidote use (defined as correct indication, proper dosing regimen, and administration within 90 min) before and after NAP implementation were compared. Association between parameters and fatal outcomes was analyzed. RESULTS: A total of 343 cases involving cyanide or cyanogenic glycoside ingestion were reported to Ramathibodi Poison Center. There were 213 cases (62.1%) during NAP (Project group) and 130 cases (37.9%) pre-NAP implementation (Before group). Implementation of NAP led to increased antidote use (39.9% in Project group versus 24.6% in Before group) and a higher rate of appropriate antidote use (74.1% in Project group versus 50.0% in Before group). All 30 deaths were presented with initial severe symptoms. Cyanide chemical source and self-harm intent were associated with death (OR: 12.919, 95% CI: 4.863-39.761 and OR: 10.747, 95% CI: 3.884-28.514, respectively). No difference in overall mortality rate (13 [10.0%] deaths before versus 17 [8.0%] deaths after NAP) was found. In subgroup analysis of 80 cases with initial severe symptoms, NAP and appropriate antidote use reduced mortality (OR: 0.327, 95% CI: 0.106-0.997 and OR: 0.024, 95% CI: 0.004-0.122, respectively). In the multivariate analysis of the cases with initial severe symptoms, presence of the NAP and appropriate antidote use independently reduced the risk of death (OR: 0.122, 95% CI: 0.023-0.633 and OR: 0.034, 95% CI: 0.007-0.167, respectively), adjusted for intent of exposure, cyanide source, age, and sex. CONCLUSIONS: After NAP implementation, both antidote use and appropriate antidote use increased. In cases presenting with severe symptoms, presence of the NAP and appropriate antidote use independently reduced the risk of mortality.

N-acetylcysteine in Cleistanthus collinus Poisoning: A Report of Two Cases in Children.

Cleistanthus collinus, also known as Oduvanthalai in Tamil, is the most commonly encountered plant poison in southern India. The leaves are used for poisoning humans (suicide or homicide) and animals (cattle and fish) and as an abortifacient, especially in rural south India. Although this poisoning is commonly reported in adults, data regarding the use of N-acetylcysteine in pediatric poisoning is lacking. We report two previously healthy male siblings of pediatric age group who ingested the liquid extracted from crushed leaves of this plant given to them by their mother as a means of deliberate harm. Both patients developed distal renal tubular acidosis, with hypokalemia. The younger sibling also developed myocardial toxicity. Other significant findings noted include hypocalcemia, hypomagnesemia and elevated liver enzymes. Both patients received supportive care along with N-acetylcysteine infusion, and showed complete recovery within 10 days.

Sweet Poisons: Honeys Contaminated with Glycosides of the Neurotoxin Tutin.

Poisonings due to consumption of honeys containing plant toxins have been reported widely. One cause is the neurotoxin tutin, an oxygenated sesquiterpene picrotoxane, traced back to honeybees (Apis mellifera) collecting honeydew produced by passionvine hoppers (Scolypopa australis) feeding on sap of the poisonous shrub tutu (Coriaria spp.). However, a pharmacokinetic study suggested that unidentified conjugates of tutin were also present in such honeys. We now report the discovery, using ion trap LC-MS, of two tutin glycosides and their purification and structure determination as 2-(ß-d-glucopyranosyl)tutin (4) and 2-[6'-(α-d-glucopyranosyl)-ß-d-glucopyranosyl]tutin (5). These compounds were used to develop a quantitative triple quadrupole LC-MS method for honey analysis, which showed the presence of tutin (3.6 ± 0.1 µg/g honey), hyenanchin (19.3 ± 0.5), tutin glycoside (4) (4.9 ± 0.4), and tutin diglycoside (5) (4.9 ± 0.1) in one toxic honey. The ratios of 4 and 5 to tutin varied widely in other tutin-containing honeys. The glycosidation of tutin may represent detoxification by one or both of the insects involved in the food chain from plant to honey.

Mutagenicity and cytotoxicity of liquid waste, press water and pond water, produced in the cassava flour industry, and of antitoxic sodium thiosulfate.

BACKGROUND: Cassava (Manihot esculenta Crantz), a plant used as food and an ingredient in industry, contains cyanogenic glycosides. The cassava root contains wastewater, popularly known as manipueira, which is a toxic substance. Its ingestion by animals causes poisoning although they react positively to treatment with sodium thiosulfate. The present research evaluates the cytotoxicity and the mutagenicity of liquid waste produced in the process of industrialization of the bitter cassava, olho-junto variety. The liquid wastes are characterized as press water, which is obtained when the cassava roots are pressed; pond water, which is press water stored in impounded ponds; and a solution of sodium thiosulfate, pure and with other waste. RESULTS: The system tests comprised root meristematic cells of Allium cepa L. and bone marrow cells of Rattus norvegicus. Treatment with saline solution was cytotoxic for Allium cepa L. and significantly reduced cell division rate. Although no treatment was cytotoxic in any of the tests with rats, the thiosulfate solution was clastogenic for the chromosomal aberrations test. CONCLUSION: Since it is harmful to the genetic material submitted within the conditions of current research, sodium thiosulfate should only be used in emergency conditions in which the benefits exceed the risks.

Norsesquiterpene glycosides in bracken ferns (Pteridium esculentum and Pteridium aquilinum subsp. wightianum) from Eastern Australia: reassessed poisoning risk to animals.

Austral bracken Pteridium esculentum contains three unstable norsesquiterpene glycosides: ptaquiloside, ptesculentoside, and caudatoside, in variable proportions. The concentration of each of the glycosides was determined in this study as their respective degradation products, pterosin B, pterosin G and pterosin A, by HPLC-UV analysis. Samples of P. esculentum collected from six sites in eastern Australia contained up to 17 mg of total glycoside/g DW, with both ptaquiloside and ptesculentoside present as major components accompanied by smaller amounts of caudatoside. Ratios of ptaquiloside to ptesculentoside varied from 1:3 to 4:3, but in all Australian samples ptesculentoside was a significant component. This profile differed substantially from that of P. esculentum from New Zealand, which contained only small amounts of both ptesculentoside and caudatoside, with ptaquiloside as the dominant component. A similar profile with ptaquiloside as the dominant glycoside was obtained for Pteridium aquilinum subsp. wightianum (previously P. revolutum ) from northern Queensland and also P. aquilinum from European sources. Ptesculentoside has chemical reactivity similar to that of ptaquiloside and presumably biological activity similar to that of this potent carcinogen. The presence of this additional reactive glycoside in Australian P. esculentum implies greater toxicity for consuming animals than previously estimated from ptaquiloside content alone.

Cleistanthus collinus poisoning.

Cleistanthus collinus is an extremely toxic plant poison. Cleistanthin A and B, the toxins of Cleistanthus collinus, are diphyllin glycosides which produce cardiac arrhythmias, urinary potassium wasting, hypoxia, metabolic acidosis and hypotension. We report ARDS, distal renal tubular acidosis and distributive shock secondary to inappropriate vasodilatation in a case following ingestion of its leaves.

Acute Cycas seed poisoning in Taiwan.

OBJECTIVE: The seeds of cycads contain cycasin and neocycasin, which belong to the family of cyanogenic glycosides. These glycosides of cycads are considered pseudocyanogenic with little potential to liberate hydrogen cyanide as other cyanogenic glycosides do. This study investigated the clinical spectrum of Cycas seed poisoning and its cyanogenic potential. METHODS: This was a retrospective chart review conducted at the Poison Control Center in Taiwan (PCC-Taiwan) from 1990 to 2001. RESULTS: Twenty-one cases of Cycas seed poisoning were identified. The reasons for seed ingestion were misuse as an edible food (70%), health promotion (10%), cancer prevention (10%), cosmetic use (5%), and gastrointestinal discomfort (5%). All patients had eaten the seeds after washing and cooking them. The time from ingestion to the onset of symptoms ranged from 30 min to 7 h (mean 2.8 h); patients had ingested between 1 to 30 seeds. Respiratory depression did not occur. Severe vomiting was the most striking symptom. All patients except one presented with gastrointestinal disturbance, and 90% sought medical care at the emergency department. Within 24 h, all patients had recovered. Six patients had blood cyanide or thiocyanate levels measured. Although the levels were higher than normal, they did not reach the toxic range. CONCLUSIONS: The cyanogenic potential of Cycas seeds is documented in our cases. The gastrointestinal symptoms were severe enough that most patients sought medical attention but recovery was quick and complete.

Cleistanthus collinus poisoning: case reports and review of the literature.

We report the cases of two previously healthy young patients who ingested the liquid extracted from the crushed leaves of Cleistanthus collinus (Family: Euphorbiaceae) in an attempt to commit suicide. Both patients developed life threatening complications such as hypokalemia, hypotension, cardiac arrhythmias, neuromuscular weakness, respiratory failure, and renal failure following a transient quiescent period of up to 4 days. Other significant findings noted include leucocytosis, coagulopathy, elevated liver enzymes, hyperchloremic metabolic acidosis, and an alkaline urinary pH. Both patients received supportive care as no specific antidote was available, and ultimately died. We have reviewed the published literature on C. collinus poisoning.

A clinical and laboratory profile of Cleistanthus collinus poisoning.

AIMS: 1. To study the clinical features in patients with Cleistanthus collinus poisoning, 2. To study in them the effect of Cleistanthus collinus poisoning on the various organ systems and metabolic parameters using standard laboratory investigations. METHODS: All patients admitted to the hospital between September 1998 and April 2000 were studied. Statistical analysis of the results was done using chi-square test, Fisher's exact test and Student's 't' test. RESULTS: Forty six cases were studied, 15 (32%) of whom died. Eighty percent of the patients were in the second to third decade. The female:male ratio was 3:2. Ingestion of the poison as a decoction prepared from the leaves and ingestion of a large number of leaves otherwise were associated with a poor outcome. While survivors remained relatively asymptomatic, fatally poisoned patients presented with significant clinical signs and symptoms, however, laboratory abnormalities such as hypokalaemia, hyponatremia, an elevated AST/LDH/CPK/CPK-MB, nonspecific ST-T changes and QTc prolongation on ECG, metabolic acidosis and hypoxia with widened alveolar-arterial oxygen difference (A-aDO2) were seen in both groups. CONCLUSION: It is a poisoning seen in the young with significant mortality. Cause of death appears to be mainly due to its cardiac and respiratory effects. Metabolic disturbances especially hypokalaemia was a prominent feature. Most deaths occurred on the 3rd day and all within a week. No specific antidote is available.

Biomarkers of exposure to cyanogens in horses with grass sickness.

To test the hypothesis that equine grass sickness may be associated with the ingestion of cyanogenic glycosides from white clover (Trifolium repens), the concentrations of whole blood cyanide, and plasma and urinary thiocyanate, the main metabolite of cyanide, were measured in 12 horses with acute grass sickness and 10 horses with subacute grass sickness, and in 43 control horses, of which 21 were co-grazing with cases of acute grass sickness, 12 grazed pastures where grass sickness had not been reported, and 10 were stabled horses. The healthy horses which grazed with cases of acute grass sickness had higher concentrations of blood cyanide, and plasma and urinary thiocyanate than the other control horses, consistent with an increased exposure to cyanogens. The horses with grass sickness had no evidence of a recent intake of cyanogens, but may have been exposed to increased levels of cyanogens before they became anorexic.

A case of nondigitalis cardiac glycoside toxicity.

A case is presented of cardiac glycoside poisoning in a 1-year-old patient from the plant Nerium oleander (common oleander). The patient had bradycardia, vomiting, altered level of consciousness, and no history of ingestion. Antibody-based digoxin assays may cross-react with other cardiac glycosides nonquantitatively. Chromatographic techniques can be used in the specific diagnosis.

Cocklebur poisoning in cattle.

Cocklebur poisoning occurred in a herd of cattle in Oklahoma during the month of July. The poisonous dicotyledonary stage of cocklebur plant growth usually occurs during the early spring in Oklahoma. In this instance, dicotyledonary sprouts were in a lowland pasture adjacent to a river. Sprouting and growth occurred after receding water and hot dry weather had created favorable conditions for germination. The diagnosis was made on the basis of the finding of the dicotyledonary stage of plant growth and evidence of the plants having been grazed, as well as the clinical signs, gross necropsy findings, and histopathologic findings in the affected cattle.

Evaluating exposures to plants.

Exposures to plants generate an exceptional amount of public concern, especially plant ingestions by children. Most clinical problems, however, involve older age groups as a result of experimentation with or overt abuse of plant parts and extracts. Of mounting concern is the sometimes uninformed and massive use of herbal preparations, currently widely available and in popular vogue. Plant exposures, from whatever source, may present as complex pharmacologic problems that may challenge the diagnostic and therapeutic skills of the physician. Although specific physiologic antagonists (antidotes) may exist for specific intoxications, basic decontamination and supportive techniques are many times all that may be offered.

Toxicologic study of carboxyatractyloside (active principle in cocklebur--Xanthium strumarium) in rats treated with enzyme inducers and inhibitors and glutathione precursor and depletor.

Male rats (10 rats/group) were treated with phenobarbital (PB), phenylbutazone (PBZ), stanozolol (3 inducers of cytochrome P450-dependent enzymes), piperonyl butoxide (PBO; a P450 inhibitor), cobaltous chloride (CoCl2; an inhibitor of hemoprotein synthesis), 5,6-benzoflavone (BNF; an inducer of cytochrome P448 dependent enzymes), cysteine [CYS; a glutathione (GSH) precursor], or ethyl maleate (EM; a GSH depletor). The rats were then given a calculated LD50 dosage (13.5 mg/kg of body weight) of carboxyatractyloside (CAT) intraperitoneally. Clinical signs of toxicosis, duration of illness, lethality, gross lesions, and hepatic and renal histopathologic lesions were recorded. Seemingly, (i) CAT toxicosis has independent lethal and cytotoxic components (PBZ decreased lethality and cytotoxicity; CoCl2 decreased cytotoxicity but not lethality; BNF decreased duration of illness, and perhaps lethality, but not cytotoxicity); (ii) CAT cytotoxicity could be partly due to an active metabolite formed by de novo-synthesized, P450-/P448-independent hemoprotein (PBZ and CoCl2 had anticytotoxic effects, but PB, stanozolol, PBO, and BNF did not); (iii) CAT detoxification may occur partly through a hemoprotein-independent, PBZ-inducible enzyme, and partly through a P448-dependent (BNF-inducible) enzyme; and (iv) CAT detoxification apparently is not P450 or GSH-dependent because PB, stanozolol, and CYS had no beneficial effects, and PBO, CoCl2, and EM did not enhance toxicosis. Metabolism of CAT may have a role in its cytotoxic and lethal effects.