Fentanyl

Anyone who has been under the knife probably has stayed under, thanks to fentanyl, which is used for surgical anesthesia and pain relief. It is 30 to 100 times more powerful than morphine and shows "less emetic activity than morphine or meperidine (Demerol)," according to the Physician's Desk Reference. That is, you're not as likely to throw up after fentanyl has been administered.

Fentanyl is a -opioid receptor agonist with high lipid solubility and a rapid onset and short duration of effects. It rapidly crosses the blood-brain barrier.

Fentanyl was first synthesized in 1960 by chemist Paul Janssen, founder of the Belgian pharmaceutical firm Janssen Pharmaceutica. His synthesis of fentanyl was to react N-phenethylpiperidone with aniline to create 4-anilino-N-phenethylpiperidine. This compound is then reacted with propionyl chloride to give pure fentanyl, which is toxic and must be diluted.

Fentanyl citrate was first used as an intravenous anesthetic called Sublimaze. Like other analgesics, it can produce insensitivity to pain without necessarily producing unconsciousness. In other forms, it is useful for treating breakthrough cancer pain or other types of moderate-to-severe chronic pain, including back pain and pain caused by sickle cell anemia.

According to the Drug Enforcement Administration (DEA), prescriptions for all types of fentanyl citrate have increased from 0.5 million in 1994 to more than 5.7 million in 2003.

THE INTRODUCTION of fentanyl in the 1960s has been important for general anesthetic practice in the U.S. It resolved problems with morphine-oxygen anesthesia, including incomplete amnesia, occasional histamine-related reactions, and marked increases in intra- and postoperative respiratory depression.

As with most narcotics intended for medical use, fentanyl has made its way into the illicit drug trade. According to DEA, illicit use of fentanyl first arose among medical professionals in the mid-1970s. Today, both pharmaceutical-grade fentanyl and its analogs produced by profiteers can be found in the black market, sometimes sold illegally as if it were China White--a storied, potent brand of heroin. When used by drug addicts, fentanyl is most often injected, but it can also be smoked or snorted.

According to DEA, more than 12 different analogs of fentanyl have been produced clandestinely and identified in U.S. illegal drug traffic. Prescription fentanyl citrate, in all of its forms, is also diverted to the street via pharmacy theft, fraudulent prescriptions, and illicit distribution by patients.

Sublimaze is used for both general and regional anesthesia and both during and after surgery. It acts almost immediately upon injection. Discovery of the compound laid the foundation for a better understanding of the structure-activity relationships of narcotic analgesics and in general spurred interest in developing compounds with greater potency and safety margins.

Another fentanyl citrate product, marketed as Actiq, is a berry-flavored lollipop or lozenge that is useful for treating cancer pain in patients who are opiate-tolerant. Health care research has determined that Actiq is being prescribed for uses beyond cancer pain to treat more general types of pain such as back or neck pain. Law enforcement officials say that Actiq's sweet taste and fast-acting effects mean it has become ripe for diversion to the black market, where the lollipops are sold as "perc-a-pops."

To treat chronic pain, fentanyl has also been marketed as the Duragesic transdermal patch. The success of the patch can be attributed to fentanyl's low molecular weight and its highly lipophilic nature, which enable it to be readily absorbed through the skin and subsequently distributed throughout the body.

According to attorney Karen L. Gendall of Robinson & Cole, Boston, in some cases, defective patches have delivered incorrect dosages and patients have overdosed through misuse or even correct use. Gendall's firm represents people who claim injury from the Duragesic patch in suits against the manufacturer. Asked if sizable awards have gone to patients who claim to have experienced these problems, Gendall replies, "Not yet."

One analog, Carfentanil, has an analgesic potency that is 10,000 times that of morphine and is used by veterinarians to immobilize certain large animals. Its whimsical trade name is Wildnil.

Fentanyl Citrate

Name
◾ N-Phenyl-N-[1-(2-phenylethyl) -4-piperidinyl]propanamide 2- hydroxy-1,2,3-propanetricarboxylate

CAS Registry
◾ 990-73-8

Other Names
◾ Actiq
◾ Duragesic
◾ Fentanest
◾ Leptanal
◾ Pentanyl
◾ Sublimaze

Introduced
1960, Janssen Pharmaceutica

Did you know that drug abusers sometimes refer to fentanyl as China White because of its narcotic potency and purity? Medical professionals are considered more likely to abuse fentanyl; the general public has limited access to the drug.