Is the yew really poisonous to you?

BACKGROUND

Taxus species, commonly referred to as yew plants, have the reputation of being inordinately toxic. Case reports which chronicle human near-fatal yew berry ingestions and countless fatalities in livestock present a sober profile to the treating toxicologist. Very often, a limited number of adverse reports influence decisions on all exposures to that potential poison. The objective of this investigation was to profile the toxicity of exposures to Taxus spp and determine what percentage of exposures were associated with significant morbidity.

METHODS

The individual computerized files of all exposures to Taxus spp were retrieved from American Association of Poison Control Centers (AAPCC) Toxic Exposure Surveillance System (TESS) and placed in a relational database. Reports from 1985-1994 were analyzed. The cases were examined to determine patient demographics, the outcome of exposures, the ultimate disposition of the patients, treatment, and symptoms. AAPCC TESS definitions were used to assess outcomes.

RESULTS

The number of exposures identified from the 10-year subset was 11,197. Children less than 12 years of age were involved in 96.4% (< 6 years 92.7%; 6-12 years, 3.7%) of the exposures. When the final outcome of the exposure was documented (n = 7269), no adverse effects occurred in 92.5% and minor effects were experienced in 7.0%. Moderate (more pronounced, but not life-threatening) effects were experienced by 30 individuals and major (life-threatening) effects occurred in 4 people. There were no fatalities. Decontamination therapy, when compared to no therapy, had no impact on patient outcome. 6.3% were admitted for psychiatric or medical care. When symptoms were related to Taxus spp exposures, the most frequent symptoms were gastrointestinal (65.5%), followed by dermal (8.3%), neurological (6.0%), and cardiovascular (6.0%).

DISCUSSION

There are limitations to the interpretation of AAPCC TESS data which may lead to bias in favor of positive outcomes. However, the large sample size may minimize the limitations.

CONCLUSION

Taxus spp exposures result only rarely in significant morbidity. Consistent with published case reports, the most common symptoms were gastrointestinal. Decontamination had no impact on patient outcome.