Painkillers or analgesic drugs are in a group of drugs that help a person achieve relief from pain. These types of drugs act on the central nervous system and temporarily affect or eliminate the feeling of pain. Opioids are the most common type of painkiller and are prescribed in Canada to treat moderate to severe pain. There are many different types of opioids and morphine is the primary one where most other prescription opioids are derived from. The dosing of opioids to treat pain is based on the patient, level of pain, and if they are taking any other opioids. For example, opioid-tolerant individuals have a higher dose ceiling than patients without tolerance. Opioid painkillers have many unpleasant side effects, such as nausea, vomiting, constipation, and causing sleep problems. Painkillers are widely used throughout Canada and are prescribed to Canadians across the country. All different types of painkillers are also abused and result in dangerous opioid addictions. Painkiller addiction is difficult to treat, and the use of opioids, whether legal or illegal have caused an epidemic across the country. Painkiller drugs come in many different forms, including tablets, capsules, syrups, solutions, nasal sprays and skin patches. The strength of these different drugs varies greatly, and most are only available with a prescription. Painkillers have a high potential for abuse, and essentially all opioids have the potential to become addictive. An addiction is a compulsive behavior, and an addict continues to use drugs despite the consequences. Painkillers create dangerous compulsive addictions, resulting in addicts going to extreme lengths to find ways to get the opioids they need. Because of the strong psychoactive properties and the high potential for abuse, opioid painkillers are heavily regulated in Canada under the Controlled Drugs and Substances Act. It is illegal to possess opioid painkillers unless you are a patient with a prescription. It is illegal to sell or even give away your prescription opioid pain medication to someone else. It is also illegal to doctor shop or seek out more than one prescription for opioid painkillers from more than one doctor.