Fentanyl: Therapeutic use
Last modified: Sunday, 31. May 2009 - 3:31 pm
Fentanyl is still a new drug. Research is ongoing on its applications and benefits. It is expected that future fentanyl derivatives will be of even greater Therapeutic use and importance. Fentanyl is used in 70% of surgeries today. Many anesthesiologists view fentanyl as a superior anesthetic because it acts only on specific nerve receptors that are primarily in the central nervous system. These sites are primarily linked with pain sensation, respiration control, and physical dependence. In contrast, general anesthetics affect the whole body and render the patient unconscious. Because fentanyl acts primarily on the central nervous system, the patient is able to remain awake throughout surgery.
Fentanyl is primarily used alone, but sometimes it is combined with other opiates such as Licodaine, Bupivacaine, or morphine in epidural administration or in some IVs. However, one of the more appealing virtues of fentanyl is that, unlike other opioids, it has a very mild effect on the emetic trigger zone of the medulla. For this reason, patients have less nausea and no vomiting when fentanyl is used. With other drugs, such as morphine, this unwanted side effect can be intense. Fentanyl also does not cause the release of histamine, which makes it safer for the cardiovascular system than morphine.
Fentanyl is widely used in epidurals for women in delivery. This is called a continuous infusion epidural analgesia (CIEA). In this method, a needle is inserted into a woman’s spinal cavity, where it offers a continuous drip of the drug throughout the birthing process. The benefit is that it lessens the pain associated with delivering a baby while still allowing the woman to have an active role in the birthing process. When administered in the lower spinal area, it is very short-acting and does not completely numb the lower body. Morphine and Demerol, which have been used more frequently in the past, render the lower extremities completely numb, making it more difficult for the patient to participate in the delivery. Thus, because the woman is able to be more active when using fentanyl, the delivery process is quicker.
Fentanyl is also used in treating people who suffer from pain associated with long-term illnesses such as cancer. It is not, however, the most inexpensive method. Transdermal fentanyl costs roughly three times what an equivalent amount of sustained-release morphine sulfate, which has similar effects on the patient, would cost. For this reason it is not used as often as other forms of pain relief unless other avenues have failed. However, some health professionals believe fentanyl offers greater benefits in helping people cope with pain. Transdermal fentanyl is faster acting than other options and lasts up to 72 hours per application. Transdermal fentanyl is considered most beneficial for people who have a consistent pain with few momentary increases in the pain. This is because there is a steady release of fentanyl into the body with no variation. It is also suitable for people who cannot swallow or open their mouths for oral medication. However, it is recommended that patients on transdermal fentanyl be given a prescription for another opiate such as morphine, hydromorphine, or oxycodone for temporary pain relief when there is a temporary increase in their suffering.
For people with ongoing pain who desire oral doses, who cannot wear a patch, or who have moments of higher pain, fentanyl is given in a lozenge or lollipop. The raspberry-colored lozenges are quickly absorbed through the buccal mucosa in the mouth and more slowly through the gastrointestinal tract. The onset of analgesia is usually within 15 minutes by this method, and one dosage lasts one to two hours. After a patient begins feeling the effects of the fentanyl and the pain is subsiding, he or she should remove the lozenge from the mouth. This reduces the intake of the drug and slows the rate at which the patient becomes tolerant of the drug.
Recently fentanyl has been tested on AIDS patients. The drug is useful in blocking pain receptors, which helps patients cope with their pain. It also helps AZT to cross the blood-brain barrier. When used alone, AZT also has several side effects that early testing has shown to be reduced when fentanyl is added to the treatment.