Cocaine paste  Coca paste (paco, basuco, oxi) is a crude extract of the coca leaf which contains 40% to 91% cocaine sulfate along with companion coca alkaloids and varying quantities of benzoic acid, methanol, and kerosene. In South America, coca paste, also known as cocaine base and, therefore, often confused with cocaine freebase in North America, is relatively inexpensive and is widely used by low-income populations. The coca paste is smoked in tobacco or cannabis cigarettes and use has become widespread in several Latin American countries. Traditionally, coca paste has been relatively abundant in South American countries such as Colombia where it is processed into cocaine hydrochloride ("street cocaine") for distribution to the rest of the world. The caustic reactions associated with the local application of coca paste prevents its use by oral, intranasal, mucosal, intramuscular, intravenous or subcutaneous routes. Coca paste can only be smoked when combined with a combustible material such as tobacco or cannabis. Coca paste use began in Bolivia and Peru in the early 1970s, first in the capital cities and then in other towns and rural areas. In a few years its use had spread to Argentina, Brazil, Colombia, Ecuador, and some Mexican cities near the border with the United States. In Argentina, cocaine paste used to sell for about 30 cents a dose, enough for a powerful two-minute high. However, its price has increased because of higher demand, among other reasons. Crude cocaine preparation intermediates are marketed as cheaper alternatives to pure cocaine to local markets while the more expensive end product is exported to United States and European markets. Freebase cocaine paste preparations can be smoked. The psychological and physiological effects of the "paco" are quite severe. Media usually report that it is extremely toxic and addictive. According to a study by Intercambios, media appear to exaggerate the effects of "paco". These stereotypes create a sense that nothing can be done to help a "paco" addict and thus stand in the way of rehabilitation programs. Basuco is the term used for cocaine paste in Colombia, the world's second biggest cocaine producer after Peru. Basuco is derived from the Spanish word for trash (basura), literally meaning "little dirty trash" (of cocaine), referring to the paste left at the bottom of a barrel after cocaine production. Basuco is mostly smoked, either rolled like a cigarette with tobacco or cannabis, or more commonly from selfmade pipes.