Paracetamol or acetaminophen, (Figure 1) is a widely
used over-the-counter analgesic (pain reliever) and antipyretic
(fever reducer). It is commonly used for the relief of
headaches, other minor aches and pains, and is a major ingredient
in numerous cold and flu remedies. In combination
with opioid analgesics, paracetamol can also be used
in the management of more severe pain such as post surgical
pain and providing palliative care in advanced cancer
patients. It was found as adulterant in illicit heroin, methaqualone,
phenobarbitone, cocaine, methamphetamine
(Atasoy et al. 1988; Battisti et al. 2006; Brunt et al. 2009).
Phenacetin (Figure 2) is an analgesic, once widely used
but nowadays its use has been declined because of its
adverse effects. It was reported as adulterant in illicit
cocaine, methaqualone and heroin samples