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Biomedical subjects

William A Watson

Publications and source records attributed to William A Watson.

11 recordsLinked to original sources
PubMed2005

TESS-based dose-response using pediatric clonidine exposures.

OBJECTIVE: The toxic and lethal doses of clonidine in children are unclear. This study was designed to determine whether data from the American Association of Poison Control Centers Toxic Exposure Surveillance System (TESS) could be utilized to determine a dose-response relationship for pediatric clonidine exposure. METHODS: 3,458 single-substance clonidine exposures in children <6 years of age reported to TESS from January 2000 through December 2003 were examined. Dose ingested, age, and medical outcome were available for 1550 cases. Respiratory arrest cases (n = 8) were classified as the most severe of the medical outcome categories (Arrest, Major, Moderate, Mild, and No effect). Exposures reported as a "taste or lick" (n = 51) were included as a dose of 1/10 of the dosage form involved. Dose ranged from 0.4 to 1980 (median 13) microg/kg. Weight was imputed based on a quadratic estimate of weight for age. Dose certainty was coded as exact (26% of cases) or not exact (74%). Medical outcome (response) was examined via logistic regression using SAS JMP (release 5.1). RESULTS: The logistic model describing medical outcome (P < 0.0001) included Log dose/kg (P = 0.0000) and Certainty (P = 0.045). CONCLUSION: TESS data can provide the basis for a statistically sound description of dose-response for pediatric clonidine poisoning exposures.

Accidents↗
PubMed2005

The Toxic Exposure Surveillance System (TESS): risk assessment and real-time toxicovigilance across United States poison centers.

The Toxic Exposure Surveillance System (TESS) is a uniform data set of US poison centers cases. Categories of information include the patient, the caller, the exposure, the substance(s), clinical toxicity, treatment, and medical outcome. The TESS database was initiated in 1985, and provides a baseline of more than 36.2 million cases through 2003. The database has been utilized for a number of safety evaluations. Consideration of the strengths and limitations of TESS data must be incorporated into data interpretation. Real-time toxicovigilance was initiated in 2003 with continuous uploading of new cases from all poison centers to a central database. Real-time toxicovigilance utilizing general and specific approaches is systematically run against TESS, further increasing the potential utility of poison center experiences as a means of early identification of potential public health threats.

Database Management Systems↗
PubMed2005

The severity of toxic reactions to ephedra: comparisons to other botanical products and national trends from 1993-2002.

OBJECTIVE: Ephedra is a botanical product widely used to enhance alertness, as a weight loss aide, and as a decongestant. Its reported adverse effects led the Food and Drug Administration (FDA) to ban ephedra-containing products in the United States in 2004. This study's purpose was to compare toxicity from botanical products containing ephedra to nonephedra products. METHODS: The Toxic Exposure Surveillance System (TESS), a national poison center database, was utilized to determine the number and outcomes of cases involving botanical products reported from 1993-2002. Cases listing both a botanical product and any other drugs or chemicals were excluded a priori. Ten-year hazard rates (moderate outcomes + major outcomes + deaths per 1000 exposures) were used to compare botanical product categories. RESULTS: There were 21,533 toxic exposures with definitive medical outcomes reported over the 10 yrs where a botanical product was the only substance involved. Of these, 4306 (19.9%) had moderate or major medical outcomes and there were two deaths, for an overall hazard score of 200 per 1000 exposures. The number of ephedra reports to poison centers increased 150-fold over the 10-yr period. The hazard rate for products that contained only ephedra was 250 per 1000 exposures and 267 per 1000 exposures for products that contained ephedra and additional ingredients; whereas the hazard score for only nonephedra botanical products was 96 per 1000 exposures. The rate ratios for multibotanical products with ephedra (RR 1.33; 95% C.I. 1.27-1.40) and for single-ingredient ephedra products (RR 1.25; 95% C.I. 1.11-1.40) were both two to six times higher than those of other common botanical products. Yohimbe-containing products had the highest hazard score (417) and rate ratio (2.08; 95% C.I. 1.59-2.80). CONCLUSION: Ephedra-containing botanical products accounted for a significant number of toxic exposures with severe medical outcomes reported to poison centers. Hazard rate analysis suggests poison center-reported events involving ephedra-containing botanical products were much more likely to result in severe medical outcomes than those involving nonephedra-containing botanical products. These data support recommendations by policymakers that the sale of ephedra should be prohibited to protect consumers. Our data suggest that the botanical product, yohimbe, may also be associated with unacceptably high risks of toxicity and should receive close scrutiny from health policymakers.

Data Collection↗
PubMed2003

Post-mortem toxicology: what the dead can and cannot tell us.

The evaluation of postmortem laboratory assays of drugs needs to be performed in a systematic manner. The condition of the body, drug characteristics, matrix and site analysis are factors which need to be considered in the proper interpretation of an autopsy specimen result.

Animals↗
PubMed2003

Evaluation of the time frame for home ipecac syrup use when not kept in the home.

INTRODUCTION: The home administration of ipecac syrup remains a recommendation in some guidelines for the management of specific pediatric poisonings. A common challenge for poison specialists is how to approach the situation when ipecac syrup is indicated but not kept in the home. This study examines whether or not ipecac syrup can be administered and produce timely emesis in this situation. METHODS: Over a 6-month period, a prospective observational study was undertaken to determine if ipecac syrup can be administered in a timely manner when it is indicated but not available in the home. Cases where ipecac syrup was indicated but not kept in the home were included if parents stated that they could obtain ipecac within 15 minutes. Timely administration and the onset of emesis were defined as < 30 min and < 60 min, respectively. RESULTS: During our study 14,603 human exposures were evaluated; ipecac syrup was recommended by a poison specialist in 75 cases, and 25 of these were included in our study. Ages ranged from 1 to 6 years. The mean time to administration of ipecac from exposure time was 40 min (SD +/- 14 min). Administration of ipecac syrup occurred in < 30 min in 20% of the cases. The mean time to first emesis from exposure was 58 min (SD +/- 13). Initial emesis occurred in < 60 min in 36% of the cases. CONCLUSIONS: Ipecac syrup was rarely recommended by our center and was frequently unavailable when it was recommended. Ipecac syrup often could not be administered in a timely manner because it was not kept in the home. Parents of pediatric patients who have a significant ingestion should not be referred to purchase ipecac syrup.

Child↗
PubMed2002

High-dose montelukast exposures in a 3-year-old and a 5-year-old child.

The leukotriene receptor antagonists (LTRAs) is a relatively new class of asthma medication with a lack of toxicity for unintentional poisoningsituations. This makes it difficult to determine which exposures require aggressive decontamination or simple monitoring in the home setting: prompting the question, "What LTRA dose is likely to produce significant toxicity?" We report a case of an unintentional poisoning with 80 mg montelukast in a 3-y-o asthmatic child that was managed in the home with observation alone and a second case of untentional 135 mg montelukast poisoning in a 5-y-o asthmatic child managed in an emergency department. In both cases, symptoms were not observed. These cases and available literature suggest that doses < 4.5 mg/kg in children result in minimal toxicity.

Accidents↗