See Bolivia; Colombia as Drug Source; International Drug Supply Systems; Mexico as Drug Source
LAUDANUM Laudanum refers to a tincture of OPIUM—an alcoholic extract (about 20%) of opium, which contains approximately 10 milligrams per milliliter of morphine. If used at all currently, it would be as an antidiarrheal. The solution is more concentrated than PAREGORIC, and smaller
volumes are given; however, their actions are almost identical. At standard doses, they rapidly and effectively treat diarrhea without producing euphoria or analgesia. The solution does contain MORPHINE and other opioid alkaloids and, at higher doses, it can be abused—as it was during the late-nineteenth and early twentieth centuries, when it was sold widely as a tonic and cure-all, in shops, by mail order, and by traveling medicine shows. Laudanum use and abuse are often mentioned in novels and plays of and about the period.
(SEE ALSO: Dover's Powder)
BRUNTON, L. L. (1996). Agents affecting gastrointestinal water flux and motility; Emesis and antiematics; Bile acids and pancreatic enzymes. In J. G. Hardman et al. (Eds.), The Pharmacological Basis of Therapeutics, 9th ed. (pp. 917-936). New York: McGraw-Hill.
Gavril W. Pasternak
LAW ENFORCEMENT See Anslinger, Harry J., and U.S. Drug Policy; Coerced Treatment for Substance Offenders; Appendix, Volume 4
LD50 In preclinical studies, the LD50 is the median lethal dose—the dose of a drug that pro duces death in 50 percent of the experimental animals tested. The LD50 can be estimated from a dose-effect curve, where the concentration of the drug is plotted against the percentage of animals that die. The ratio of the LD50 to the ED50 (the median effective dose) indicates the therapeutic index of a drug for that effect and suggests how selective the drug is in producing its desired effects. In clinical studies, the concentration of the drug required to produce toxic effects can be compared to the concentration required for therapeutic effects in the population to esimate the clinical therapeutic index.
(SEE ALSO: Research: Animal Model)
Gilman, A. G., et al., (Eds.). (1990). Goodman and Gilman's the pharmacological basis of therapeutics, 8th ed. New York: Pergamon.
Was this article helpful?