Journal of toxicology. Clinical toxicology
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Acute valproic acid intoxication is an increasing problem, accounting for more than 5000 calls to the American Association of Poison Control Centers in 2000. The purpose of this paper is to review the pharmacology and toxicology of valproic acid toxicity. Unlike earlier antiepileptic agents, valproic acid appears to function neither through sodium channel inhibition nor through direct gamma-aminobutyric acid agonism, but through an indirect increase in regional brain gamma-aminobutyric acid levels. ⋯ Metabolic and hematologic derangements have also been described. Management of acute valproic acid ingestion requires supportive care and close attention to the airway. The use of controversial adjunctive therapies, including extracorporeal drug elimination and L-carnitine supplementation, will be discussed.
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J. Toxicol. Clin. Toxicol. · Jan 2002
The effect of the nitric oxide synthesis inhibitor L-NAME on amitriptyline-induced hypotension in rats.
Hypotension induced by tricyclic antidepressants is multifactorial. Previous animal experiments suggest a contribution from nitric oxide production. Our study aimed to evaluate the role of nitric oxide in amitriptyline-induced hypotension using N-nitro-L-arginine methyl ester, a nitric oxide synthesis inhibitor, and 3-morpholino sydnonimine, a nitric oxide donor, in anesthetized rats. ⋯ N-nitro-L-arginine methyl ester is found to be effective in temporarily improving hypotension and prolonging survival time but does not affect overall mortality. Because this effect was antagonized by 3-morpholino sydnonimine, nitric oxide production appears to contribute to the pathophysiology of amitriptyline-induced hypotension.
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J. Toxicol. Clin. Toxicol. · Jan 2002
Case ReportsA case of levetiracetam (Keppra) poisoning with clinical and toxicokinetic data.
Levetiracetam (Keppra) is a new anticonvulsant used to treat partial complex seizures that is also being investigated for its mood-stabilizing properties. Although its precise mechanism of action is unknown, levetiracetam does not appear to directly interact with the GABA system. We report the first intentional overdose with levetiracetam including clinical effects and serial serum concentrations. ⋯ In overdose, levetiracetam is sedating and causes respiratory depression, however, recovery is rapid with supportive care. This is the first reported case of levetiracetam overdose; serial serum concentrations suggest first-order elimination even at concentrations 10-40 fold higher than therapeutic.
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J. Toxicol. Clin. Toxicol. · Jan 2002
The National Poisons Information Centre in Sri Lanka: the first ten years.
Poisoning is a major health concern in Sri Lanka, which has a very high morbidity and mortality from pesticide poisoning. Poisoning, which continues to be in the first five leading causes of death, accounts for about 80,000 hospitalizations and over 3,000 deaths per year. The National Poisons Information Centre in Sri Lanka, thefirst such centre to be established in South Asia, completed 10 years service in 1997. The 4,070 calls received in thefirst 10 years are analyzed and compared with the national hospitalization pattern. ⋯ Although enquiries to the NPIC averaged only 0.5% of poisoning hospitalizations, they were sufficiently representative of the national pattern to predict that increasing utilization of the NPIC would offer a much needed service, both for
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J. Toxicol. Clin. Toxicol. · Jan 2002
Case ReportsAcute cyanide intoxication treated with a combination of hydroxycobalamin, sodium nitrite, and sodium thiosulfate.
An 80-year-old diabetic patient was admitted to the hospital because of sudden unconsciousness and severe metabolic acidosis. His son reported the possibility of cyanide poisoning. ⋯ Supportive therapy and the following antidotes--sodium nitrite two doses 300 mg i.v., sodium thiosulfate 3 g i.v., and hydroxocobalamin 4 g in 24 hours--were administered immediately and the patient completely recovered in 48 hours. Our observations suggest that timely and appropriate use of antidotes for cyanide intoxication may prevent death, even in aged diabetic patients.