RT Book, Section A1 Lapoint, Jeff M. A2 Hoffman, Robert S. A2 Howland, Mary Ann A2 Lewin, Neal A. A2 Nelson, Lewis S. A2 Goldfrank, Lewis R. SR Print(0) ID 1108432541 T1 Cannabinoids T2 Goldfrank's Toxicologic Emergencies, 10e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 9780071801843 LK accessemergencymedicine.mhmedical.com/content.aspx?aid=1108432541 RD 2024/10/16 AB Cannabis has been used for more than 4000 years. The earliest documentation of the therapeutic use of marijuana is the fourth century b.c. in China.156 Cannabis use spread from China to India to North Africa, reaching Europe around a.d. 500.126 In colonial North America, cannabis was cultivated as a source of fiber. Like cocaine and morphine, cannabis was the focus of research efforts in the 19th century. Although the active chemical constituents of the former were isolated during this time, that of cannabis remained elusive.91 This is due to the fact that the active compounds of morphine and cocaine are both alkaloids and were possible to extract with the technological means of the time, whereas the methods to isolate the active terpenes in cannabis were not available to researchers until several decades later.