Alphamethylfentanyl

α-methylfentanyl is an opioid analgesic that is an analogue of fentanyl.

α-methylfentanyl was invented in 1979 and appeared on the black market under the name "China White". It was first identified in the bodies of two drug overdose victims in Orange County, California, in December 1979, who appeared to have died from opiate overdose but tested negative for any known drugs of this type. Over the next year there were 13 more deaths and eventually the responsible agent was identified as α-methylfentanyl.

α-methylfentanyl was significant as the first example of a "designer drug" which had been developed entirely by clandestine chemists for sale as an illicit recreational drug rather than as a product of legitimate scientific research; while new synthetic drugs such as DOB and ALD-52 had previously appeared on the black market, they had been reported in scientific research papers prior to their appearance as recreational drugs.

α-methylfentanyl was placed on the Schedule I list in September 1981, only two years after its appearance on the street, but already other analogues were being developed. Following the appearance of α-methylfentanyl on the market, over 10 new analogues of fentanyl have been reported, starting with para-fluorofentanyl, followed by α-methylacetylfentanyl, then by the highly potent 3-methylfentanyl, and subsequently many others such as β-hydroxyfentanyl, ohmefentanyl, β-hydroxythiofentanyl and β-hydroxy-4-methylfentanyl. The development of such a wide structural family of novel narcotic drugs was a major factor responsible for the implementation of the Federal Analog Act which for the first time attempted to control entire families of drugs based on their structural similarity rather than scheduling each drug individually as they appeared. Whether this has been a successful strategy is debatable, it could be argued that specifying restrictions on new drugs which have never yet been made only encourages clandestine chemists to become more creative to attempt to circumvent the legal restrictions.

α-methylfentanyl has similar effects to fentanyl. It is less potent by weight due to reduced binding affinity to its target site, yet longer acting as the α-methyl group interferes with binding to metabolic enzymes which break the drug down. Since fentanyl itself is highly potent and notorious for causing fatal overdoses when abused, and also very short lasting with addicts often administering doses every hour, α-methylfentanyl could have several advantages over the parent compound as a recreational drug. Side effects of fentanyl analogues are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression which can be life-threatening.