Vicodin contains a mixture of hydrocodone and paracetamol. The opioid pain reliever is hydrocodone. An opioid is often referred to as a drug. Paracetamol is a less effective pain reliever that increases the effects of hydrocodone. You can buy Vicodin online. Vicodin tablets are used to relieve mild to moderate pain. Vicodin may also be included for uses not mentioned in this medication guide.