FENTANYL PATCH Indicated for chronic pain in opioid-tolerant patients, severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate .Discontinue or taper all other extended-release opioids when beginning fentanyl transdermal therapy .
Fentanyl is an opioid used as a pain medication and together with other medications for anesthesia. Fentanyl is also made illegally and used as a recreational drug, often mixed with heroin or cocaine. It has a rapid onset and effects generally last less than two hours.
Fentanyl is an opioid analgesic drug more powerful than morphine. In patch form it is used to provide a steady stream of the drug to treat moderate to severe chronic pain.
Despite the theoretical benefits of maintaining steady-state kinetics with the patch compared to the wide variations of blood levels, termed peaks and troughs, associated with oral administration of most drugs, the transdermal system of administration has numerous drawbacks. The onset of pharmacological activity is very slow because of slow absorption of the drug through the intact skin. For instance, it typically takes 4 hours for circulating plasma levels of scopolamine to even be detected once the patch is applied, and the time to reach peak levels averages 24 hours. Thus the anesthesiologist cannot expect any significant therapeutic effect immediately following an anesthetic unless the scopolamine patch is applied many hours before the start of a procedure. The fentanyl patch takes 24–72 hours to reach steady state, and once it is removed, the residual fentanyl in the skin continues to be absorbed for hours. It takes approximately 17 hours for fentanyl blood levels to drop by 50% once the patch is removed, so fentanyl interactions with sedatives, hypnotics, and other opioids are still possible hours after the patch has been removed. Thus removal of the patch does not quickly eliminate the risk of fentanyl interactions with other drugs.