NapaDol® is a combination of two Paracetamol 325 mg and Tramadol 37.5 mg tablet. Tramadol Hydrochloride is an opioid analgesic that acts on the central nervous system. Tramadol is pure non selective agonists of the m, d, and k opioid receptors with a higher affinity for the m receptors. Unlike morphine, Tramadol Hydrochloride has no respiratory depressant effect. Paracetamol (acetaminophen) is a pain reliever and a fever reducer which is used to treat many conditions such as headache, muscle aches, arthritis, backache, toothaches, colds, and fevers. Combination of Paracetamol and Tramadol exerts a synergistic effect and subsides mutual side effects.