Tamiko is worried that she will become addicted to the drug she has been taking to relieve her pain. She is most likely taking a (n) :

She is most likely taking an; opiate

Opiate belongs to the class of drugs called opioids and it is produced from opium (gotten from the poppy plant). Opiate is used in the treatment of pain. Opiate produces intense feelings of well-being and happiness. Opiate is regarded as a drug of high abuse potential and it can be addictive to some individuals. Examples of opiate are morphine and heroin.