Patent medicine the patent medicines, some of their makers began replacing the opium tincture laudanum with acetanilide, a particularly toxic non-steroidal anti-inflammatory drug with analgesic as well as antipyretic properties that had been introduced into medical practice under the name "Antifebrin" by A. Cahn and P. Hepp in 1886. But this ingredient change probably killed more of the nostrum's users than the original narcotics did, since acetanilide not only caused an alarming cyanosis due to methemoglobinemia but was later discovered to cause liver and kidney damage. The occasional reports of acetanilide-induced cyanosis prompted the search for supposedly less toxic aniline derivatives, such
Prescription drug Prescription drug A prescription drug (also prescription medication or prescription medicine) is a pharmaceutical drug that legally requires a medical prescription to be dispensed. In contrast, over-the-counter drugs can be obtained without a prescription. The reason for this difference in substance control is the potential scope of misuse, from drug abuse to practicing medicine without a license and without sufficient education. Different jurisdictions have different definitions of what constitutes a prescription drug. "Rx" (℞) is often used as a short form for prescription drug in North America - a contraction of the Latin word ""recipe"" (an imperative form of "recipere")