MedlinePlus: Butorphanol Nasal Spray - Provides information on usage, precautions, side effects and brand names when available. Data provided by government agencies and health-related organizations. - http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a601204.html
MedlinePlus: Butorphanol Injection - Provides information on usage, precautions, side effects and brand names when available. Data provided by government agencies and health-related organizations. - http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682667.html
Stadol - Full prescribing information from RxList. - http://www.rxlist.com/cgi/generic2/butor.htm