Discontinued. Taxol (paclitaxel) has been discontinued in the us. There was originally concern because of the environmental impact of its original sourcing, no longer used, from the pacific yew. In addition, the assignment of rights, and even the name itself, to bristol-myers squibb were the subject of public debate and congressional hearings.
Allergies. Those who have allergies to the drug or yew tree and those with adverse reactions.