Fentanyl patches

Other than possibly for the insensible perspiration they absorb, transdermal patches tend to operate as thermodynamically static systems, meaning as com-positionally fixed systems, from the moment they are applied until their removal. Marketed ethanol-driven estradiol and fentanyl patches are exceptions because they meter out ethanol and drive it into the stratum corneum to propel the absorption process. Compositional steadfastness is still the rule, however, and it is this feature that bestows the zero-order delivery attribute on the ordinary transdermal patch. Drug is present within the patches in reservoir amounts whether or not the reservoir compartment is easily distinguished, for there must be enough drug to sustain delivery over the full course of patch wear. 

Conversion from transdermal fentanyl to CR tablets Eighteen hours following the removal of the transdermal fentanyl patch, treatment with CR tablets can be initiated. Although there has been no systematic assessment of such conversion, a conservative oxycodone dose, approximately 10 mg every 12 hours of CR tablets, should be initially substituted for each fentanyl transdermal patch 25 mcg/h. Closely follow the patient for early titration as there is very limited clinical experience with this conversion. 

Which of the following statements about fentanyl patches is true ... 

E. Fentanyl patches have the same effect as fentanyl, only in a time-release manner. Thus, the purpose of the question is delineation of opioid effects—respiratory depression and constipation. The respiratory depression is life-threatening when the patch is used in nonambulatory patients, and it is therefore contraindicated for that purpose. 

Similarly, fentanyl is a teratogenic drug contraindicated for use during pregnancy. The fentanyl patch does not induce anesthesia (loss of consciousness) but does produce analgesia. 

In developing protein and peptide trans-dermal delivery systems, one must be mindful of the high interindividual variation in drug absorption across the skin. Large variations in bioavailability have been demonstrated with fentanyl patches, initially intended for postoperative pain relief but later abandoned due to unacceptable variability among individuals receiving the same dose [9]. Response in postoperative patients to the application of a fentanyl patch ranged from ineffective pain relief to severe respiratory depression, and effects were correlated with variations in plasma fentanyl levels [9]. 

If disturbances of gastrointestinal function prevent the use of oral sustained-release morphine, the fentanyl transdermal system (fentanyl patch) can be used over long periods. Furthermore, buccal transmucosal fentanyl can be used for short episodes of breakthrough pain (see Alternative Routes of Administration). Administration of strong opioids by nasal insufflation has been shown to be efficacious, and nasal preparations are now available in some countries. Approval of such formulations in the USA is growing. In addition, stimulant drugs such as the amphetamines have been shown to enhance the analgesic actions of the opioids and thus may be very useful adjuncts in the patient with chronic pain. 

In line with the trend towards prolonged application intervals, 3M and Purdue have started developing a fentanyl patch that is effective for 7 days. It will be interesting to see how well long-term application and occlusion at a particular site will be tolerated in comparison with the relatively good dermal tolerance of three days treatment. 

Flannagan, L.M., Butts, J.D., and Anderson, W.H., Fentanyl patches left on dead bodies — potential source of drug for abusers, J. Forensic Set, 41, 320, 1996. 

Anonymous, Fentanyl patches are new drug on street, Addict. Lett., 8, 3, 1992. 

Inhalant abuse is also termed volatile solvent abuse. It should be noted that many drugs besides those classified as inhalants can be administered by inhalation, including marijuana, cocaine, heroin, methamphetamine, fentanyl patches, and nicotine. These drugs are not volatile solvents and have different physical and chemical properties therefore, they are not classified as inhalants. Inhalants are chemicals that are volatile, meaning they can readily vaporize from... 

A 57-year-old woman using transdermal fentanyl (75 pg/ hour) developed a reduced respiratory rate and bilateral pinpoint pupils when an upper body warming blanket was used as a normal postoperative procedure (24). The resultant increase in skin temperature significantly enhanced skin perfusion, and increased the systemic absorption of fentanyl from the intracutaneous fentanyl depot, leading to sjmptoms of opioid overdose. She recovered after removal of the fentanyl patch and the intravenous administration of naloxone 60 pg. 

Transdermal fentanyl was the cause of an opioid overdose when a 77-year-old man with a history of severe arthritis developed respiratory failure after starting epidural diamorphine-bupivacaine mixture for postoperative pain (50). The fentanyl patch was removed, the epidural infusion was stopped, and naloxone was given to counteract the excessive opioid effects. 

Transdermal fentanyl avoids the discomfort of injections and reduces fluctuations in drug concentrations. In an open study of transdermal fentanyl patches 50 pg for postoperative pain management in 15 thoracotomy patients, two patients had nausea and one had erythema over the site of apphcation of the patch (55). 

The long-term use of transdermal fentanyl in patients with chronic non-cancer pain (back pain, leg pain, arthritic pain, trigeminal neuralgia, and intestinal cystitis), which is controversial, has been discussed (62). Transdermal fentanyl was effective and safe and improved quality of life and independent living. However, these case reports were collected by authors closely associated with the company that manufactures transdermal fentanyl patches a degree of case selectivity and bias might have occurred. 

A 71-year-old woman was found unconscious, with reduced respiration and miotic pupils, having previously had nausea, dizziness, and drowsiness (73). She had inappropriately applied a fentanyl patch 100 pg/hour a day before the symptoms occurred. She recovered fuUy after treatment with intravenous naloxone 0.4 mg. 

A 24-year-old woman, with a history of polysubstance abuse and extensive psychiatric history, presented with acute opioid overdose caused by the intentional oral ingestion of a fentanyl patch (Duragesic) (74). 

Frolich MA, Giannotti A, ModeU JH, FroUch M. Opioid overdose in a patient using a fentanyl patch dnrrng treatment with a warming blanket. Anesth Analg 2001 93(3) 647-8. 

E Oxycodone/acetaminophen would be the most appropriate drug to start for this patient s acute postsurgical pain. The onset of action is rapid, and it can be titrated to effect. Morphine and meperidine have active metabolites that can accumulate in this patient with renal dysfunction, increasing the risk for seizures, sedation, and respiratory depression. The fentanyl patch is primarily indicated in chronic pain. The onset is slow, and the patches cannot be titrated up rapidly to cover acute pain, nor titrated down as the patient recovers and requires less opioid. 

Fentanyl is used chronically in the management of major pain in humans. One of the common side effects of therapy with opioids is constipation. However, a recent cohort analysis of a large California HMO looking at the incidence of constipation in patients receiving opioid analgesics showed a low incidence of constipation in the patients receiving fentanyl patches (3.7%). 

Treatment is based on the patient s clinical presentation. Basic and advanced life support measures should be performed as needed. Activated charcoal may be utilized to adsorb orally administered fentanyl, such as the ingestion of a fentanyl patch. Whole bowel irrigation should be considered to speed the... 

Hardwick WE, King WD, and Palmisano PA (1997) Respiratory depression in a child unintentionally exposed to transdermal fentanyl patch. Southern Medical Journal 90 962-964. 

The site of application for fentanyl patches (an analgesic) depends on the brand of product used. Read the individual patient information leaflet for more details. 

A fentanyl patch placed every 72 h may provide a more convenient dosing regimen when patients are on a stable oral dosing program. 

Fentanyl patches have been used to provide analgesia. The most dangerous adverse effect of this mode of administration is... 

A fentanyl patch is available for the treatment of severe chronic pain. This dosage form delivers fentanyl transdermally and provides effective analgesia for periods of up to 72 hours. In 1999, fentanyl also became available in a lollipop dose form for absorption from the oral cavity. 

Fentanyl has been used safely in a number of patients receiving MAOIs. However, a fatality due to a serotonin-like syndrome has occurred in a patient taking an MAOI given fentanyl, and another case of hypertension and tachycardia has occurred. The authors of one of these reports, considered that there was insufficient evidence to conclude that patients on MAOIs can be given fentanyl safely, and call for all cases of combined use to be reported. Case reports also describe the safe use of alfentanil, remifen-tanil, and sufentanil. However, one UK manufacturer of fentanyl patches recommends that they should not be used during the use of, or within 14 days of stopping, an MAOI. ... 

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