Painkiller abuse is the use of drugs for purposes other than prescribed. Painkillers are mainly used to relieve pain. The drugs are available from local drug stores, chemists, hospitals, or the internet. The drugs can be snorted, injected, or taken orally. There are different types of painkillers that serve the same purpose. The drugs are prescribed by doctors according to severity of the patient. Height, weight, size, and age are factors to be considered during administration of the drugs.