Journal of toxicology. Clinical toxicology最新文献

Background: Lindane (gamma-benzene hexachloride), commonly used as a treatment for pediculosis, has been associated with adverse reactions and has recently undergone increased regulation.

Objective: We sought to describe the patterns of a large number of lindane exposures reported to poison centers in Texas during 1998-2002.

Methods: Data on all lindane exposures for pediculosis reported to the Texas Poison Center Network were analyzed.

Results: There were 528 reported human exposures to lindane for pediculosis. The incidence of lindane exposures has decreased by 52% from 1998 to 2002. Misuse or abuse of lindane was reported in at least 87% of the cases. Of those cases with a known patient age, 45% were less than age 6 yrs, 23% age 6-19 yrs, and 32% over age 19 yrs. Female patients accounted for 55% of reported cases. Of those cases with a known medical outcome, 61% reported no effects. The most frequently reported symptoms were vomiting, nausea, and ocular irritation or ocular pain.

Conclusion: The number of reported lindane exposures in Texas is decreasing. The majority of reported exposures involve misuse or abuse of the product. The pattern of symptoms reported in Texas was consistent with the literature.

Whole bowel irrigation (WBI) should not be used routinely in the management of the poisoned patient. Although some volunteer studies have shown substantial decreases in the bioavailability of ingested drugs, no controlled clinical trials have been performed and there is no conclusive evidence that WBI improves the outcome of the poisoned patient. Based on volunteer studies, WBI should be considered for potentially toxic ingestions of sustained-release or enteric-coated drugs particularly for those patients presenting greater than two hours after drug ingestion. WBI should be considered for patients who have ingested substantial amounts of iron as the morbidity is high and there is a lack of other options for gastrointestinal decontamination. The use of WBI for the removal of ingested packets of illicit drugs is also a potential indication. WBI is contraindicated in patients with bowel obstruction, perforation, ileus, and in patients with hemodynamic instability or compromised unprotected airways. WBI should be used cautiously in debilitated patients or in patients with medical conditions that may be further compromised by its use. The concurrent administration of activated charcoal and WBI may decrease the effectiveness of the charcoal. The clinical relevance of this interaction is uncertain. A review of the literature since the preparation of the 1997 Whole Bowel Irrigation Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.

Objective: The aim of the our study was to investigate the role of adenosine receptors on cardiovascular toxicity induced by amitriptyline, a tricyclic antidepressant agent. Therefore, the hypothesis of this study was that adenosine receptor antagonists would improve and/or prevent amitriptyline-induced hypotension and conduction abnormalities in an anesthetized rat model of amitriptyline intoxication.

Methods: Two separate experimental protocols were performed. Amitriptyline intoxication was induced by the infusion of amitriptyline 0.94 mg/kg/min until 40-45% reduction of mean arterial pressure (MAP). Sodium cromoglycate (10 mg/kg) was injected i.v. to inhibit the A3 receptor-mediated activation of mast cells. In protocol 1, after amitriptyline infusion, while control animals (n=8) were given dextrose solution, treatment groups received a selective adenosine A1 antagonist DPCPX (8-cyclopentyl-1,3-Dipropylxanthine, 20 microg/kg/min, n=8) or a selective A2a antagonist CSC (8-(3-chlorostyryl) caffeine, 24 microg/kg/min, n=8) for 60 minutes. In protocol 2, after the sodium cromoglycate, while control group of rats (n=8) recevied a dextrose solution, treatment groups of rats were administered DPCPX (20 microg/kg/min, n=8) or CSC (24 microg/kg/min, n=8) infusion to block adenosine A1 and A2a receptors for 20 minutes before amitriptyline infusion. After pretreatment with adenosine antagonists, all rats were given a dose of 0.94 mg/kg/min of amitriptyline infusion during 60 minutes. Outcome measures were mean arterial pressure (MAP), heart rate (HR), QRS duration and survival rate.

Results: In protocol 1, amitriptyline infusion significantly reduced MAP and prolonged QRS within 15 minutes. HR was not changed significantly during the experiments. While dextrose did not improve MAP and QRS prolongation, DPCPX or CSC administration developed a significant improvement in MAP compared to the dextrose group within 10 min (88.5 +/- 2.8%, 75.6 +/- 4.7% and 50.1 +/- 14.7%, p<0.01, p<0.05, respectively). Both DPCPX and CSC decreased QRS prolongation (p<0.05) and increased median survival time significantly (log-rank test, p<0.00001). In protocol 2, pretreatment with DPCPX or CSC prevented the reduction in MAP due to amitriptyline toxicity compared to rats administered dextrose infusion (99.5 +/- 2.6%, 102.4 +/- 2.6%, 81.8 +/- 5.4, p<0.01 at 30 min; 98.0 +/- 2.9%, 93.5 +/- 6.0%, 64.9 +/- 4.7, p<0.001, p<0.01 at 40 min, respectively). Pretreatment with DPCPX or CSC also prevented the QRS prolongation (p<0.05) and increased median survival time significantly (log-rank test, p<0.0001).

Conclusion: Adenosine antagonists were found to be effective in improving hypotension, QRS prolongation and survival time in our rat model of amitriptyline toxicity. Additionally, amitriptyline-induced cardiotoxicity was abolished by pretreatment with adenosine receptor antagonists. These results s

Background: Cyproheptadine is reported to be effective in treating serotonin syndrome. It is only available as an oral preparation and administration after SSRI overdose treated with activated charcoal is problematic. Sublingual administration may circumvent this problem. The pharmacokinetics of sublingual cyproheptadine are not characterized. This study compares the pharmacokinetics of cyproheptadine following oral and sublingual administration.

Methods: Cross-over, non-blinded, volunteer study using five healthy males. Eight milligrams of oral and sublingual cyproheptadine were administered on separate occasions with a one-week washout period. Sublingual arm subjects were pretreated with 50 g of oral activated charcoal 30 min prior to cyproheptadine, to prevent any gut absorption. Serum cyproheptadine concentration was measured at baseline, 30 min, and 1, 2, 3, 4, 6, 8, and 10 h by liquid chromatography and mass spectroscopy.

Results: Mean C(max) for oral and sublingual were 30.0 microg/L and 4.0 microg/L respectively: mean T(max) were 4 h and 9.6 h; mean AUC were 209 and 25 microg x hr/L. Mean +/- SEM within-subject difference between oral and sublingual C(max) was 25.9 +/- 4.1 (p = 0.003) and AUC was 184 +/- 31 (p = 0.004).

Conclusions: Serum concentrations after sublingual cyproheptadine are significantly less than after oral administration. At these concentrations, the sublingual route is unlikely to be effective in treating serotonin syndrome.

We report a 67-yr-old woman with hepatitis C-related liver cirrhosis and hepatoma who had developed severe bone marrow suppression after taking Cantharanthus roseus as an alternative anticancer treatment. The patient developed severe pancytopenia with initial presentations of vomiting, diarrhea, oral ulcer, and fever about 1 week after taking 5-days' course of Cantharanthus roseus. Bone marrow biopsy showed autolysis, which indicated massive necrosis of the hematopoietic cells. There was no malignant cell infiltration. The patient also had severe gastrointestinal disturbances, bacteremia, urinary tract infection, and impaired renal and liver function. Supportive care with broad-spectrum antibiotics, granulocyte colony-stimulating factor, repeated blood transfusions, and albumin supplement was given. She recovered and was discharged after 48 days hospitalization. Coadministration of Cantharanthus roseus and cisapride was noted, and these two drugs are both substrates of cytochrome P450 3A4 enzymes (CYP 3A4). Because the vinca alkaloids are extensively metabolized by the liver cytochrome P450 enzymes, poor hepatic function and drug-herb interaction might predispose the patient to develop the bone marrow toxicity. This case report demonstrated possible effect of oral dose of vinca alkaloids and also hinted that all the substrates and inhibitors of CYP 3A4 have propensity to interfere with metabolism of vinca alkaloids.

The administration of a cathartic alone has no role in the management of the poisoned patient and is not recommended as a method of gut decontamination. Experimental data are conflicting regarding the use of cathartics in combination with activated charcoal. No clinical studies have been published to investigate the ability of a cathartic, with or without activated charcoal, to reduce the bioavailability of drugs or to improve the outcome of poisoned patients. Based on available data, the routine use of a cathartic in combination with activated charcoal is not endorsed. If a cathartic is used, it should be limited to a single dose in order to minimize adverse effects of the cathartic. A review of the literature since the preparation of the 1997 Cathartics Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.

Introduction: Dichlorodiphenyltrichloroethane (DDT) ingestion is an uncommon cause of poisoning worldwide. To date, no cases of renal impairment after oral intake of DDT in humans have been reported. We describe the clinical course and management of two patients presenting after DDT ingestion, one of whom developed acute oliguric renal failure.

Case report: A father and son mistook DDT powder for flour while preparing fish for a meal, and after eating they developed symptoms compatible with acute organochlorine insecticide poisoning. Both were intubated endotracheally due to recurrent convulsions and loss of consciousness followed by admission to the intensive care unit. Both cases developed severe metabolic acidosis. Acute oliguric renal failure (ARF) was diagnosed in the son in the second day, with a blood urea nitrogen level of 47 mg/dl and creatinine 6.4 mg/dl. Urinalysis disclosed abundant RBCs on the third day. Vigorous fluid resuscitation and strict monitoring helped reverse its clinical course by the tenth day. Both patients recovered within two weeks and were discharged without sequelae.

Conclusion: Clinicians should not overlook the possibility of DDT poisoning in the differential diagnosis of acute renal failure and seizures. More strict measures should be taken to prohibit misidentification of DDT and similar products, particularly in the developing world.

Glyphosate (N-[phosphonomethyl]glycine) is a nonselective herbicide used in agriculture as a foliage spray for the control and the destruction of herbaceous plants. Adverse skin reactions due to contact with this compound have been rarely described. We report a case of a 78-year-old woman presenting with extensive chemical burns on her trunk and legs caused by accidental contact with a glyphosate-surfactant formulation. The lesions healed in four weeks without scarring.