Definition: Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).
Input: Abstract: The users of illicit drugs is endangered by both unpredictable concentrations of the drugs and by unexpected adulterants that may be present. Cocaine has been adulterated or admixed with numerous substances, among them local anesthetics, amphetamine, phencyclidine, and strychnine. We report three cases of thallium poisoning following nasal insufflation of a substance that was believed to have been cocaine. 
 Which is the apt title for the abstract? option1: Thallium poisoning in cocaine abusers. option2: Accessory cells as primary target of human immunodeficiency virus HIV infection [letter]
Output:
Thallium poisoning in cocaine abusers.