An investigation of the relationship between antemortem and postmortem drug concentrations in blood

In the field of postmortem toxicology, principles from pharmacology and toxicology are combined in order to determine if exogenous substances contributed to ones death. In order to make this determination postmortem and (whenever available) antemortem blood samples may be analyzed. This project focused on evaluating the relationship between postmortem and antemortem blood drug levels, in order to better define an interpretive framework for postmortem toxicology. To do this, it was imperative to evaluate the differences in antemortem and postmortem drug concentrations, determine the role microbial activity and evaluate drug stability. Microbial studies determined that the bacteria Escherichia coli and Pseudomonas aeruginosa could use the carbon structures of drugs as a source of food. This would suggest prior to sample collection, microbial activity could potentially affect drug levels. This process however would stop before toxicologic evaluation, as at autopsy blood samples are stored in tubes containing the antimicrobial agent sodium fluoride. Analysis of preserved blood determined that under the current storage conditions sodium fluoride effectively inhibited microbial growth. Nonetheless, in many instances inconsistent drug concentrations were identified. When comparing antemortem to postmortem results, diphenhydramine, morphine, codeine and methadone, all showed significantly increased postmortem drug levels. In many instances, increased postmortem concentrations correlated with extended postmortem intervals. Other drugs, such as alprazolam, were likely to have concentration discrepancies when short antemortem to death intervals were coupled with extended postmortem intervals. While still others, such as midazolam followed the expected pattern of metabolism and elimination, which often resulted in decreased postmortem concentrations. The importance of drug stability was displayed when reviewing the clonazepam/ 7-aminoclonazepam data, as the parent drug commonly converted to its metabolite even when stored in the presence of a preservative. In instances of decreasing postmortem drug concentrations the effect of refrigerated storage could not be ruled out. A stability experiment, which contained codeine, produced data that indicated concentrations could continue to decline under the current storage conditions. The cumulative data gathered for this experiment was used to identify concentration trends, which subsequently aided in the development of interpretive considerations for the specific analytes examined in the study.

The effects of a family-based educational intervention on the prevention of lead poisoning in children

The effects of lead exposure may endure through one's lifetime and can negatively effect educational performance. While the link between the cause and effects of lead poisoning has been identified, the application of lead health education as the mechanism of disease prevention has not. The purpose of this study was to examine whether caregiver participation in a family-based educational intervention can result in decreased lead exposure in low socioeconomic children. ^ Participants (n = 50) were caregivers of children 12 to 36 months of age. They were randomly selected from an urban clinic and randomly assigned to either a treatment or control group. The experimental design of this study involved two clinic visits. Parents in the treatment group were given the educational intervention during the first clinic visit while those in the control group were given the intervention during the second clinic visit. The intervention was reinforced with a lead education brochure coupled with a video on childhood lead poisoning. One instrument was used to test parental knowledge of lead poisoning both pre- and post-intervention. Blood lead levels in pediatric participants were tested using two blood lead screens approximately three to four months apart determined by well-child check-up schedules. ^ Findings from the analysis of variance showed the interaction between the change in blood lead level between the children's first and second clinic visits and the treatment level. This demonstrated a significant interaction between the differences of first and second clinic visits blood lead levels and the presence or absence of the educational intervention. ^ The findings from an analysis of covariance support that caregivers in the treatment group have significantly higher scores on the second clinic visit scores on the CLKT than the caregivers in the control group. These data suggest that the educational treatment is effective in increasing the knowledge of caregivers about the dangers of lead poisoning and the strategies for lead poisoning prevention. ^ Conclusions indicate that the education of adult caregivers can affect blood lead levels of children, the educational treatment increased the knowledge of caregivers, caregivers were able to carry out procedures taught, and caregivers retained knowledge over time. ^