Transdermal fentanyl: an updated review of its pharmacological properties and therapeutic efficacy in chronic cancer pain control

A new once-a-day fentanyl citrate patch (Fentos Tape) could be a new treatment option in patients with end-of-dose failure using a 72-h transdermal fentanyl matrix patch

PURPOSE

The recommended dosing interval for transdermal fentanyl is every 72 h. However, some patients will have "end-of-dose failure," which may be seen as an increase of episodes of severe pain flares at the third day after application of the patch. A new once-a-day fentanyl patch was developed in Japan since 2010. This study aimed to assess the efficacy of the once-a-day fentanyl citrate patch for patients with cancer-related pain receiving the 72-h transdermal fentanyl not lasting 72 h.

METHODS

We performed a cross-sectional retrospective analysis of 445 inpatients with the 72-h transdermal fentanyl at Higashi Sapporo Hospital. We could switch to the once-a-day fentanyl citrate patch if patients reported inadequate pain relief beyond 48 h after application of the 72-h transdermal fentanyl. Patients recorded baseline scores for background pain intensity (PI) and the frequency of use of daily rescue medication for breakthrough cancer pain (BTcP).

RESULTS

Of all patients, 10.1% showed the increase in PI of 30% or more baseline PI on the third day after application of the 72-h transdermal fentanyl. Of patients, 84.4% were converted from equivalent dose of the 72-h transdermal fentanyl to the once-a-day fentanyl citrate patch. On the third day after switching, 60.5% of patients showed a reduction of more than 30% from baseline PI. Switching to the once-a-day fentanyl citrate patch significantly reduced the mean frequency of daily rescue dose for BTcP.

CONCLUSIONS

A once-a-day fentanyl citrate patch provided stable pain control. Its use may be considered as the dominant strategy for patients receiving a 72-h transdermal fentanyl not lasting 72 h.

Pharmacokinetic study between a bilayer matrix fentalyl patch and a monolayer matrix fentanyl patch: single dose administration in healthy volunteers

Aims

Transdermal fentanyl is a well established treatment for cancer pain. The aim of the present study is to assess the relative bioavailability of fentanyl from two different transdermal systems by evaluating plasma drug concentrations after single administration of Fentalgon® (test), a novel bilayer matrix type patch, and Durogesic SMAT (reference), a monolayer matrix type patch. In the Fentalgon patch the upper 6% fentanyl reservoir layer maintains a stable concentration gradient between the lower 4% donor layer and the skin. The system provides a constant drug delivery over 72 h.

Methods

This was an open label, single centre, randomized, single dose, two period crossover clinical trial, that included 36 healthy male volunteers. The patches were applied to non-irritated and non-irradiated skin on the intraclavicular pectoral area. Blood samples were collected at different time points (from baseline to 120 h post-removal of the devices) and fentanyl concentrations were determined using a validated LC/MS/MS method. Bioequivalence was to be claimed if the 90% confidence interval of AUC(0,t) and C_max ratios (test: reference) were within the acceptance range of 80–125% and 75–133%, respectively.

Results

The 90% confidence intervals of the AUC(0,t) ratio (116.3% [109.6, 123.4%]) and C_max ratio (114.4% [105.8, 123.8%] were well included in the acceptance range and the C_max ratio also met the narrower bounds of 80–125%. There was no relevant difference in overall safety profiles of the two preparations investigated, which were adequately tolerated, as expected for opioid-naïve subjects.

Conclusions

The new bilayer matrix type patch, Fentalgon®, is bioequivalent to the monolayer matrix type Durogesic SMAT fentanyl patch with respect to the rate and extent of exposure of fentanyl (Eudra/CT no. 2005-000046-36).

Noninterventional study of transdermal fentanyl (fentavera) matrix patches in chronic pain patients: analgesic and quality of life effects

Fentanyl is considered to be an effective, transdermal treatment of chronic, cancer, and noncancer pain. This noninterventional, clinical practice-based study, on 426 patients attending 42 practices, assessed a proprietary, Aloe vera-containing, transdermal fentanyl matrix patch (Fentavera), for its analgesic effects, patients' quality of life (QoL) effects, tolerability, and adhesiveness. Study outcomes were mean changes from baseline of patient (11-point scales) and physician (5-point scales) ratings. After 1 and 2 months treatment, there were significant (P < 0.0001) decreases in patients' ratings of pain intensity, and impairment of walking, general activity, sleep quality, and QoL. For each parameter, the patient response rate was >30% at 2 months (response = 2-point decrease on 11-point rating scale). In a large majority of patients, the physicians rated the matrix patch as good or very good for analgesic effect, systemic and local tolerance, and adhesiveness. There were 30 adverse events in 4.2% of patients and analgesic comedications were reduced during treatment compared to before treatment. It is concluded, from this population-based data, that the proprietary, transdermal fentanyl matrix patch is effective and safe for chronic pain management in clinical practice, with significant positive analgesic and QoL effects, while being well tolerated and exhibiting good or very good adhesiveness.

Good clinical practice guide for opioids in pain management: the three Ts - titration (trial), tweaking (tailoring), transition (tapering)

BACKGROUND AND OBJECTIVES

Achieving good clinical practice in the use of opioids as part of a comprehensive pain management regimen can face significant challenges. Despite guidelines from governmental and pain society/organization sources, there are still significant hurdles. A review of some basic tenets of opioid analgesia based on current published knowledge and experiences about this important healthcare imperative is warranted.

CONTENT

Consistent with guidelines, the literature supports using the lowest total opioid dose that provides adequate pain control with the fewest adverse effects. Titration (or trial) during opioid initiation is a way of starting low and going slow (and assessing the appropriateness of a specific opioid and formulation). Recognizing that multiple factors contribute to an individual's personal experience of pain, the physical, psychological, social, cultural, spiritual, pharmacogenomic, and behavioral factors of the individual patient should be taken into account (tweaking, or tailoring). Finally, for those patients for whom transition (tapering) from opioid is desired, doing so too rapidly can have negative consequences and minimization of problems during this step can be achieved by proper tapering.

CONCLUSION

We conclude that a simultaneously aggressive, yet conservative, approach is advocated in the literature in which opioid therapy is divided into three key steps (the 3 T's): titration (or trial), tweaking (or tailoring), and transition (or tapering). Establishment of the 3 T's along with the application of other appropriate good medical practice and clinical experience/judgment, including non-pharmacologic approaches, can assist healthcare providers in the effort to achieve optimal management of pain.

Indication of Adequate Transdermal Fentanyl Dose in Opioid Switching From Oral Oxycodone in Patients With Cancer

OBJECTIVE

The present study aimed to examine affecting factors for conversion ratio and to predict adequate fentanyl dose for patients with cancer pain in opioid switching from oral oxycodone.

METHODS

Patient characteristics, biochemical parameters, daily oxycodone dose, and reasons for opioid switching were retrospectively collected. The effect of variables on the conversion ratio was analyzed by multiple regression analysis.

RESULTS

Regression analysis for the data from 122 patients suggested that the typical conversion ratio was 95:1; however, this ratio was significantly reduced in patients taking a daily oral morphine-equivalent dose of <45 mg/d and in patients with poor pain control to 52:1 and 64:1, respectively.

CONCLUSION

We should carefully and rapidly control pain in opioid switching based on the adequate dose indicated in this study.

Efficacy and safety of a six-hour continuous overlap method for converting intravenous to transdermal fentanyl in cancer pain

CONTEXT

Managing cancer pain often requires opioid medications, such as fentanyl, which is frequently initiated parenterally, and then converted to transdermal form. Little evidence exists to guide this conversion.

OBJECTIVES

To observe the efficacy and safety of a six-hour continuous overlap method for converting intravenous fentanyl (IVF) to transdermal fentanyl (TF) in patients with cancer pain.

METHODS

We switched from IVF to TF using a 1:1 (IVF:TF) conversion ratio and overlapped a continuous, nontapered dose of IVF until six hours after TF placement. Pain intensity by Numeric Rating Scale, number of rescue analgesic doses, and presence and severity of opioid-related adverse events were recorded immediately before TF placement, and at six, 12, 18, and 24 hours thereafter.

RESULTS

A total of 17 consecutive patients with cancer pain controlled on IVF were converted to TF. Median age was 65 years, 10 were female, and all had Stage IV cancer. Pain intensity at six and 24 hours remained stable; a slight but statistically significant increase in Numeric Rating Scale was noted at 12 and 18 hours (P=0.01 and 0.02, respectively); however, there was no significant increase in number of rescue doses throughout the observation period. Only one patient experienced opioid-related adverse events.

CONCLUSION

A continuous six-hour overlap method is a safe and effective strategy when converting from IVF to TF in patients with cancer pain. A slight increase in pain intensity may occur, but does not lead to increased rescue doses.

Oral transmucosal drug delivery for pediatric use

The formulation of medicines for children remains a challenge. An ideal pediatric formulation must allow accurate dose administration and be in a dosage form that can be handled by the target age group. It is also important to consider the choices and the amount of excipients used in the formulation for this vulnerable age group. Although oral formulations are generally acceptable to most pediatric patients, they are not suitable for drugs with poor oral bioavailability or when a rapid clinical effect is required. In recent years, oral transmucosal delivery has emerged as an attractive route of administration for pediatric patients. With this route of administration, a drug is absorbed through the oral mucosa, therefore bypassing hepatic first pass metabolism and thus avoiding drug degradation or metabolism in the gastrointestinal tract. The high blood flow and relatively high permeability of the oral mucosa allow a quick onset of action to be achieved. It is a simple and non-invasive route of drug administration. However, there are several barriers that need to be overcome in the development of oral transmucosal products. This article aims to provide a comprehensive review of the current development of oral transmucosal delivery specifically for the pediatric population in order to achieve systemic drug delivery. The anatomical and physiological properties of the oral mucosa of infants and young children are carefully examined. The different dosage forms and formulation strategies that are suitable for young patients are discussed.

Transdermal fentanyl for pain due to chemoradiotherapy-induced oral mucositis in nasopharyngeal cancer patients: evaluating efficacy, safety, and improvement in quality of life

This study evaluated the efficacy, safety, and quality of life (QoL) measure of transdermal fentanyl (TDF) for moderate-to-severe pain due to oral mucositis caused by chemoradiotherapy in patients with advanced nasopharyngeal carcinoma (NPC). Patients with NPC who experienced moderate-to-severe oral mucosal pain during chemoradiotherapy (n=78) received TDF for pain relief. Pain relief and QoL were compared before and after treatment. The mean numeric rating scale score was reduced from 7.41±0.96 before treatment to 5.54±0.86, 3.27±0.73, 2.88±0.62, and 2.82±0.68 on days 1, 4, 7, and 10, respectively, after treatment (P<0.001). Karnofsky performance status and SPAASMS (Score for pain, Physical activity levels, Additional pain medication, Additional physician/emergency room visits, Sleep, Mood, and Side effects) scores showed significant improvement after treatment, indicating an improved QoL of patients (both P<0.001). The most common adverse reactions were nausea and vomiting (10.26%). No serious life-threatening adverse events and no symptoms of drug withdrawal were observed. TDF is effective, safe, and improves QoL in treating pain due to oral mucositis caused by chemoradiotherapy in NPC patients.

Transdermal fentanyl for cancer pain

BACKGROUND

Opioid drugs have been used for many years to relieve pain. Transdermal fentanyl offers one option for delivering and maintaining pain relief in patients with moderate or severe cancer pain.

OBJECTIVES

To determine the analgesic efficacy of transdermal fentanyl for relief of cancer pain, and to assess the adverse events associated with the use of transdermal fentanyl for relief of cancer pain.

SEARCH METHODS

The following databases were searched: Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 4 of 12); MEDLINE (1966 to May 2013); EMBASE (1974 to May 2013; CANCERLIT (PubMED) (November 2012); and ClinicalTrials.gov (May 2013).

SELECTION CRITERIA

Published randomised controlled trials (RCTs) using placebo or active comparators reporting on the analgesic effect of transdermal fentanyl in adults and children with cancer pain. Studies with fewer than 10 participants were excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two review authors. We extracted any available data on the number or proportion of patients with 'no worse than mild pain' or treatment success (very satisfied, or very good or excellent on patient global impression scales), together with information about adverse events and withdrawals.

MAIN RESULTS

We identified nine studies meeting the inclusion criteria, including a Turkish study that is awaiting formal translation. There were 1244 participants randomised in classically designed RCTs, of whom 1197 had evaluable data, and 138 patients enrolled in an enriched enrolment, randomised withdrawal (EERW) trial. Overall, 600 participants were treated with transdermal fentanyl patches, 382 with various formulations of morphine, 36 with methadone, and 221 with paracetamol plus codeine. There were major sources of potential bias, including lack of blinding, small size, high levels of attrition, and inconsistent reporting.We could not compare data in a meaningful analysis regarding adverse events such as nausea, abdominal pain, gastrointestinal bleeding, and confusion. These events may have been attributable to the underlying disease process.There were insufficient comparable data for meta-analysis to be undertaken or to produce numbers needed to treat (NNT) for the analgesic effect. In seven studies with 461 participants reporting pain intensity results after about two weeks, the mean or median pain scores were on the borderline of mild and moderate pain. Most participants would have had no worse than mild pain on treatment. Another reported that 77% of participants using transdermal fentanyl had an undefined successful outcome. Fewer participants experienced constipation with transdermal fentanyl (28%) than with oral morphine (46%), giving a risk ratio of 0.61 (95% CI 0.47 to 0.78); the NNT to prevent constipation was 5.5 (95% CI 3.8 to 10).

AUTHORS' CONCLUSIONS

The randomised trial literature for effectiveness of transdermal fentanyl is limited, but it is an important medicine. Most studies recruited fewer than 100 participants and did not provide data appropriate for meta-analysis. Only a few reported how many patients had good pain relief but, where data were reported, a majority had no worse than mild pain within a reasonably short time period. The evidence pointed to a useful and significant reduction in complaints about constipation for transdermal fentanyl compared with oral morphine.

Update on prescription extended-release opioids and appropriate patient selection

Chronic pain is largely underdiagnosed, often undertreated, and expected to increase as the American population ages. Many patients with chronic pain require long-term treatment with analgesic medications, and pain management may involve use of prescription opioids for patients whose pain is inadequately controlled through other therapies. Yet because of the potential for abuse and addiction, many clinicians hesitate to treat their patients with pain with potentially beneficial agents. Finding the right opioid for the right patient is the first - often complicated - step. Ensuring that patients continue to properly use the medication while achieving therapeutic analgesic effects is the long-term goal. Combined with careful patient selection and ongoing monitoring, new formulations using extended-release technologies incorporating tamper-resistant features may help combat the growing risk of abuse or misuse, which will hopefully reduce individual suffering and the societal burden of chronic pain. The objective of this manuscript is to provide an update on extended-release opioids and to provide clinicians with a greater understanding of which patients might benefit from these new opioid formulations and how to integrate the recommended monitoring for abuse potential into clinical practice.

Adverse effects associated with non-opioid and opioid treatment in patients with chronic pain

Chronic pain is a debilitating condition that is associated with many common diseases; this places a major burden on the healthcare system. There are currently numerous analgesic agents available for the treatment of chronic pain. In general, the oral non-opioid analgesic, paracetamol, is recommended for the initial treatment of mild to moderate pain. Therapeutic doses of paracetamol do not appear to result in hepatotoxicity, although overdose may lead to acute liver failure. Current data suggest that paracetamol has acceptable gastrointestinal tolerability. Another class of non-opioid analgesic with confirmed efficacy for the treatment of chronic mild to moderate pain are non-steroidal anti-inflammatory drugs (NSAIDs), although this efficacy is offset by the potential of adverse gastrointestinal events. In particular, non-selective NSAIDs, also known as cyclooxygenase (COX) inhibitors, carry an increased risk of serious upper gastrointestinal complications, including ulcers, perforation and bleeding. The introduction of COX-2 inhibitors provided a NSAID-based option with improved gastrointestinal safety, but increased risk of cardiovascular effects. Opioids are powerful analgesic agents used to treat moderate to severe chronic pain. However, treatment with opioids is associated with a number of common adverse effects, including constipation, nausea or vomiting, pruritus, somnolence or cognitive impairment, dry mouth, tolerance or dependence and urinary retention. Although there are multiple strategies in place to manage adverse events that arise from both non-opioid and opioid analgesic therapy, a better understanding of the mechanisms involved in the development of specific drug-related adverse effects is required along with proper prescribing practices and adequate physician/patient education. Balanced against the adverse effects of pain management medications, there is a need to be mindful of the widespread, often serious, adverse consequences of poorly managed pain itself.

Pharmacokinetics, Tolerability, and Performance of a Novel Matrix Transdermal Delivery System of Fentanyl Relative to the Commercially Available Reservoir Formulation in Healthy Subjects

A novel transdermal formulation of fentanyl-containing dipropylene glycol droplets dispersed in a silicone matrix with a rate-controlling membrane was developed. Healthy male subjects (n = 24) received repeated 72-hour applications of fentanyl (50 mug/h) as the novel matrix and the conventional reservoir formulations in a randomized, 2-way crossover study. Blood samples were collected, and serum concentrations of fentanyl were assayed using liquid chromatography with mass spectrometry detection. The mean area under the curve (AUCtau) and peak concentrations (C(max)) of the matrix formulation were 84 838 pg.h/mL and 1680 pg/mL, respectively. Ratio and 90% confidence intervals of AUCtau and C(max) between the 2 formulations were within 80% to 125%. Adherence of the matrix formulation was higher than the reservoir formulation (62.5 vs 56.2%, P < .0001), without affecting skin irritation. Vital signs and adverse events of the 2 formulations were similar in nature and frequency. The novel matrix formulation displayed enhanced adherence and resulted in similar pharmacokinetics and tolerability as the reservoir formulation.

Linezolid is associated with serotonin syndrome in a patient receiving amitriptyline, and fentanyl: a case report and review of the literature

We report a unique case of an adverse interaction between the oxazolidinone antibiotic linezolid, the tricyclic antidepressant amitriptyline and the opioid analgesic fentanyl in a 68-year-old woman with advanced ischemic peripheral arterial disease and sepsis, under empirical antibiotic treatment. We also summarize the current relevant literature as identified via PubMed, EMBASE, and PsycINFO as well as reference sections of selected articles.

Multicenter clinical study for evaluation of efficacy and safety of transdermal fentanyl matrix patch in treatment of moderate to severe cancer pain in 474 chinese cancer patients

OBJECTIVE

Although a new matrix formulation fentanyl has been used throughout the world for cancer pain management, few data about its efficacy and clinical outcomes associated with its use in Chinese patients have been obtained. This study aimed to assess the efficacy and safety of the new system in Chinese patients with moderate to severe cancer pain.

METHODS

A total of 474 patients with moderate to severe cancer pain were enrolled in this study and were treated with the new transdermal fentanyl matrix patch (TDF) up to 2 weeks. All the patients were asked to record pain intensity, side effects, quality of life (QOL), adherence and global satisfaction. The initial dose of fentanyl was 25 μg/h titrated with opioid or according to National Comprehensive Cancer Network (NCCN) guidelines. Transdermal fentanyl was changed every three days.

RESULTS

After 2 weeks. The mean pain intensity of the 459 evaluated patients decreased significantly from 5.63±1.26 to 2.03±1.46 (P<0.0001). The total remission rate was 91.29%, of which moderate remission rate 53.16%, obvious remission rate 25.49% and complete remission rate 12.64%. The rate of adverse events was 33.75%, 18.78% of which were moderate and 3.80% were severe. The most frequent adverse events were constipation and nausea. No fatal events were observed. The quality of life was remarkably improved after the treatment (P<0.0001).

CONCLUSION

The new TDF is effective and safe in treating patients with moderate to severe cancer pain, and can significantly improve the quality of life.

Analgesic effect of switching from oral opioids to a once-a-day fentanyl citrate transdermal patch in patients with lung cancer

A new once-a-day fentanyl citrate transdermal patch was developed in Japan. We retrospectively investigated analgesic and adverse effects of this drug in 24 patients with lung cancer. All patients were started on this patch by switching from an oral opioid. The mean pain score before switching was 2.45 (0-5); 48 hours after switching, 15 of the 24 patients showed a decreased pain score and the mean score (2.00) was significantly lower than that before switching. Of the 16 patients who had adverse effects of oral opioids, 7 patients showed improvement in their symptoms after switching. Two patients showed adverse effects of the drug but their symptoms were mild, and no patient required dose decrease. This new transdermal patch could be a useful treatment option for cancer pain.

A simple liquid chromatography-tandem mass spectrometry method for determination of plasma fentanyl concentration in rats and patients with cancer pain

A fentanyl patch is widely used for the treatment of cancer pain. Its few adverse effects include constipation and drowsiness. The absorption volume of transdermally applied fentanyl may differ according to its site of application and variability in patch adhesion. Since fentanyl is predominantly metabolized by the drug-metabolizing enzyme cytochrome P450 (CYP) 3A4 in the liver, its concentration may vary in cases of physiologically reduced CYP3A4 activity in the liver (liver disease and aging) or on co-administration of drugs. The clinical significance of measuring plasma concentration of fentanyl is high, but conventional methods require complicated processes such as solid-phase extraction and liquid-liquid extraction before the sample is injected into an HPLC system. In this study, a simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for determining plasma fentanyl concentrations by deproteinization with acetonitrile. A recovery test was conducted using an absolute calibration curve to confirm the method's linearity and inter- and intra-day reproducibility. The required plasma volume for detection was reduced from 1 mL in the conventional method to 20 µL in the present study, and a good calibration curve was obtained in the concentration range from 0.05 to 5 ng/mL. These findings suggest that the method for sample preparation and quantification developed in this study are appropriate for measuring fentanyl concentration in human plasma in clinical settings.

Effects of Application Site and Subject Demographics on the Pharmacokinetics of Fentanyl HCl Patient-Controlled Transdermal System (PCTS)

INTRODUCTION

The fentanyl HCl patient-controlled transdermal system (PCTS) is a self-contained, preprogrammed, needle-free system currently in development for acute pain management in a medically supervised setting. The objectives of these studies were to evaluate skin application sites for the fentanyl HCl PCTS and to evaluate the effect of patient demographics on its pharmacokinetics.

METHODS

The first study was a randomised, open-label, single-centre, 3-treatment, crossover study in which the fentanyl HCl PCTS was applied to the upper outer arm, lower inner arm or chest of healthy volunteers. Fentanyl 25 microg was then delivered via this system twice during the first 20 minutes of every hour for 24 hours. The pharmacokinetics of fentanyl were determined and analysed for each application site using ANOVA. The second study was a nonrandomised, nonblind, multicentre, sequential treatment study. Healthy volunteers received fentanyl HCl 40 microg via the PCTS three times during the first 30 minutes of each hour for 3 hours. After a 5- to 10-day washout period, fentanyl HCl 120 microg was administered intravenously during the first 30 minutes of each hour for 3 hours as a reference treatment. Pharmacokinetic parameters were determined for the fentanyl HCl PCTS, and results were analysed using ANOVA. Safety and tolerability were evaluated in both studies.

RESULTS

Application of the system to the upper outer arm or chest resulted in similar maximum serum concentrations (Cmax; 1.193 and 1.176 microg/L, respectively) and areas under the serum concentration-time curve (AUC24-25; 1.033 and 1.015 microg h/L). However, both Cmax and AUC24-25 were less when the system was applied to the lower inner arm (0.859 microg/L and 0.757 microg x h/L). Subject age, bodyweight, sex and ethnicity had no significant effect on pharmacokinetic parameters. No serious adverse events were reported in either study during or after administration of the fentanyl HCl PCTS.

CONCLUSION

Fentanyl HCl is comparably absorbed from the PCTS when it is applied to the upper outer arm or chest. The pharmacokinetics of fentanyl HCl delivered by the PCTS are unaffected by sex, age, race or weight.

The efficacy of transdermal fentanyl for pain relief after endoscopic submucosal dissection: a prospective, randomised controlled trial

OBJECTIVE

Epigastric pain management following endoscopic submucosal dissection is an important consideration. This study aimed to investigate the utility and safety of fentanyl patches for pain relief after the procedure.

METHODS

Patients who were scheduled to undergo endoscopic submucosal dissection were prospectively randomised to either a transdermal fentanyl patch group or a placebo control group. An additional pethidine was intravenously administered when pain developed and a numerical rating scale was used to evaluate both pre- and post-procedural pain.

RESULTS

One hundred and ten patients were randomly assigned to receive either a 12 mcg/h fentanyl patch or a control patch on the night before the procedure. The fentanyl patch group had significantly lower pain scores immediately following the procedure (mean, 5.17 vs. 4.26, p=0.030). Maximal pain scores during the first 24 h (5.43 vs. 4.46, p=0.038) and pain scores on the day after the procedure (2.98 vs. 1.20, p<0.001) were also lower in the fentanyl patch group. In addition, the fentanyl patch group required a significantly lower dose of pethidine for pain management (24.54 vs. 11.25, p=0.004).

CONCLUSIONS

The application of a transdermal fentanyl patch is an effective, convenient, and safe method to control epigastric pain after endoscopic submucosal dissection.

A new drug release method in early development of transdermal drug delivery systems

In vitro drug release tests are a widely used tool to measure the variance between transdermal product performances and required by many authorities. However, the result cannot provide a good estimation of the in vivo drug release. In the present work, a new method for measuring drug release from patches has been explored and compared with the conventional USP apparatus 2 and 5 methods. Durogesic patches, here used as a model patch, were placed on synthetic skin simulator and three moisture levels (29, 57, 198 μL cm⁻²) were evaluated. The synthetic skin simulators were collected after 1, 2, 3, 4, 6, and 24 hours and extracted with pH 1.0 hydrochloric acid solution. The drug concentrations in the extractions were measured by isocratic reverse phase high-pressure liquid chromatography. The results showed that, with the increasing moisture level on the synthetic skin simulator, the drug release rate increased. In comparison with the conventional USP method, the drug release results performed by the new method were in more correlation to the release rate claimed in the product label. This new method could help to differentiate the drug release rates among assorted formulations of transdermal drug delivery systems in the early stage of development.

Polymer excipients enable sustained drug release in low pH from mechanically strong inorganic geopolymers

Improving acid resistance, while maintaining the excellent mechanical stability is crucial in the development of a sustained and safe oral geopolymer dosage form for highly potent opioids. In the present work, commercially available Methacrylic acid-ethyl acrylate copolymer, Polyethylene-glycol (PEG) and Alginate polymer excipients were included in dissolved or powder form in geopolymer pellets to improve the release properties of Zolpidem, herein acting as a model drug for the highly potent opioid Fentanyl. Scanning electron microscopy, compression strength tests and drug release experiments, in gastric pH 1 and intestinal pH 6.8 conditions, were performed. The polymer excipients, with an exception for PEG, reduced the drug release rate in pH 1 due to their ability to keep the pellets in shape, in combination with the introduction of an insoluble excipient, and thereby maintain a barrier towards drug diffusion and release. Neither geopolymer compression strength nor the release in pH 6.8 was considerably impaired by the incorporation of the polymer excipients. The geopolymer/polymer composites combine high mechanical strength and good release properties under both gastric and intestinal pH conditions, and are therefore promising oral dosage forms for sustained release of highly potent opioids.

Simple and rapid HPLC-UV method using an ultrafine particle octadecylsilane for determination of residual fentanyl in applied Durotep MT transdermal matrix patches and its clinical application

A few complicated and time-consuming methods are available for the determination of residual fentanyl in Durotep MT transdermal patches, however, their application to clinical settings is limited. The aim of this study was to develop a simple and rapid HPLC-UV method using an ultrafine particle octadecylsilane (ODS) for the determination of residual fentanyl in applied Durotep MT transdermal matrix patches. Patch extraction involved sonicating a shredded Durotep MT patch in acetonitrile for 15 min. Fentanyl separation was completed within 2 min using a 2.3-μm particle ODS column (50 × 4.6 mm i.d.) at a flow rate of 1.5 mL/min. No peaks interfering with fentanyl (1.27 min) and papaverine (0.89 min) as an internal standard were observed. The calibration curve for fentanyl was linear over the range of 0.015-9.0 mg as a Durotep MT patch. The intra- and inter-assay precisions and accuracies of each patch were within 5.3% and 103.9-110.5% and within 8.2% and 97.1-104.3%, respectively. The validated method was applied to determine residual fentanyl in Durotep MT patches used in 35 cancer patients. Although the plasma fentanyl concentration was significantly correlated with its measured absorption rate, the measured absorption rate normalized fentanyl concentration showed a large inter-individual variation. The validated simple and rapid HPLC-UV method established in the present study is helpful for evaluating the absorption rate of fentanyl in patients receiving Durotep MT patches.

Is morphine still the best reference opioid?

SUMMARY Cancer and noncancer pain can usually be managed according to the WHO analgesic ladder and, in many countries, morphine remains the first-line opioid of choice for chronic severe pain. There have been many advances in the use of opioids for moderate-to-severe pain control in recent years. Consequently, the position of morphine as the gold standard became gradually more questioned, mostly because of serious adverse effects and the availability of different opioids and new formulations. The place of morphine as the first-line option is based on reasons of familiarity, availability or cost rather than medical advantages. In recent years, a number of systematic reviews failed to demonstrate superiority of morphine over other opioids in terms of efficacy or tolerability. Moreover, some strong opioids have shown improved tolerability or convenience. Currently, morphine might still be considered as a reference drug for equivalent dosing, but not for strategic healthcare decisions, as it has not demonstrated clinical or pharmacological superiority over other opioids. Therefore, there is a lack of evidence to sustain the role of morphine as the gold standard in the treatment of chronic severe pain.

Fentanyl pectin nasal spray: in breakthrough pain in opioid-tolerant adults with cancer

Fentanyl pectin nasal spray (PecFent®) uses a novel pectin-based delivery system that turns from an aqueous solution into a gel when applied to mucosal surfaces. Fentanyl is absorbed in a controlled manner from the pectin gel formed in the nasal cavity, and has a rapid onset of pain relief and duration of action that matches the time course of a typical episode of breakthrough pain in cancer (BTPc). Relative to administration as oral transmucosal fentanyl, fentanyl administered as fentanyl pectin nasal spray is more rapidly absorbed, reaches higher maximum plasma concentrations and has greater bioavailability. In the treatment of BTPc in two randomized, double-blind, crossover trials in opioid-tolerant adults, fentanyl pectin nasal spray (100-800 μg titrated doses) was significantly more effective than placebo in reducing pain intensity and provided a significantly faster onset of pain relief than oral immediate-release morphine. During long-term treatment of BTPc episodes, fentanyl pectin nasal spray consistently provided effective pain relief in an open-label, 16-week trial. Most patients were satisfied or very satisfied with the ease of use and convenience of the nasal spray. Fentanyl pectin nasal spray 100-800 μg was generally well tolerated and was not associated with nasal tolerability problems.

The management of cancer pain

The experience of pain in cancer is widely accepted as a major threat to quality of life, and the relief of pain has emerged as a priority in oncology care. Pain is associated with both the disease as well as treatment, and management is essential from the onset of early disease through long-term survivorship or end-of-life care. Effective relief of pain is contingent upon a comprehensive assessment to identify physical, psychological, social, and spiritual aspects and as a foundation for multidisciplinary interventions. Fortunately, advances in pain treatment and in the field of palliative care have provided effective treatments encompassing pharmacological, cognitive-behavioral, and other approaches. The field of palliative care has emphasized that attention to symptoms such as pain is integral to quality cancer care.

Synthetic geopolymers for controlled delivery of oxycodone: adjustable and nanostructured porosity enables tunable and sustained drug release

In this article we for the first time present a fully synthetic mesoporous geopolymer drug carrier for controlled release of opioids. Nanoparticulate precursor powders with different Al/Si-ratios were synthesized by a sol-gel route and used in the preparation of different geopolymers, which could be structurally tailored by adjusting the Al/Si-ratio and the curing temperatures. In particular, it was shown that the pore sizes of the geopolymers decreased with increasing Al/Si ratio and that completely mesoporous geopolymers could be produced from precursor particles with the Al/Si ratio 2∶1. The mesoporosity was shown to be associated with a sustained and linear in vitro release profile of the opioid oxycodone. A clinically relevant release period of about 12 h was obtained by adjusting the size of the pellets. The easily fabricated and tunable geopolymers presented in this study constitute a novel approach in the development of controlled release formulations, not only for opioids, but whenever the clinical indication is best treated with a constant supply of drugs and when the mechanical stability of the delivery vehicle is crucial.

Fentanyl sublingual: in breakthrough pain in opioid-tolerant adults with cancer

Fentanyl is a potent opioid with a short duration of action. Fentanyl sublingual has been formulated as a rapidly disintegrating tablet that is quickly absorbed, producing a fast onset of analgesia. In two randomized, double-blind clinical trials, fentanyl sublingual as single fixed or titrated doses reduced pain intensity during breakthrough pain episodes to a significantly greater extent than placebo in opioid-tolerant cancer patients. In a fixed-dose phase II trial and a titrated-dose phase III trial, fentanyl sublingual (as a single 400 μg dose and as titrated doses) reduced mean pain intensity difference (PID) to a significantly greater extent than placebo over the entire treatment period (up to 60 minutes), reaching statistical significance 15 minutes post-dose. In the titrated-dose study, the mean sum of PID (area under the PID vs time curve) at 30 minutes post-dose was significantly greater with fentanyl sublingual than placebo, with significant improvements in PID seen at 10 minutes maintained at 60 minutes post-dose. In the phase III study, patients receiving fentanyl sublingual were more satisfied with their treatment than patients receiving placebo (measured using the Patient Global Evaluation of Medication score), and almost half of all fentanyl sublingual recipients were satisfied or very satisfied with their treatment. Fentanyl sublingual was generally well tolerated in the two trials and most adverse events were mild to moderate in intensity.

A comprehensive LC-MS-based quantitative analysis of fentanyl-like drugs in plasma and urine

Fentanyl, norfentanyl, alfentanil, sufentanil, remifentanil and 3-methylfentanyl are potent, short-acting, synthetic narcotic analgesics that are not revealed in standard opiate immunoassays. In this article, a fully validated analytical method for the determination of these fentanyl-type compounds in plasma and urine is presented, consisting of a liquid-liquid extraction followed by a LC-MS/MS analysis using electrospray ionisation in the positive ionisation mode. Fentanyl-d(5) and norfentanyl-d(5) were used as internal standards. The lower LOQ in plasma and urine was 0.1 ng/mL for fentanyl, norfentanyl, alfentanil, remifentanil and 3-methylfentanyl, and 0.2 ng/mL for sufentanil. The method proved linear over a concentration range of 0.2-50 ng/mL for sufentanil and 0.1-50 ng/mL for all other analytes, with correlation coefficients of 0.998 or better. The analytical procedure showed excellent selectivity and precision (all CVs below 15%) for all analytes. Accuracy was good, except for sufentanil, where deviations of more than 15% from nominal concentrations were observed. No matrix effects were observed, and stability of stock and internal standard solutions was within acceptability limits.

Fentanyl Transdermal Therapy System (TTS-Patch) for Post-Traumatic Blunt Chest Injury

Proper post-extubation pain control in traumatic blunt chest injury represents a challenge to provide adequate analgesia for proper lung inflation and to prevent re-intubation. In this case, the average opioid (Remifentanil) infusion drip in a traumatic blunt chest injury patient in the 48 hours prior to extubation was calculated and converted to the equivalent analgesic one of the Fentanyl Transdermal Therapeutic System (Fentanyl TTS Patch). The analgesic gap before the onset of action for the applied fentanyl patch was covered by frequent injections of tramadol. Evaluation of the Fentanyl TTS effect through the post-extubation period was carried out by measuring the analgesic effect on a visual analogue scale, the alertness status by simple sedation score, while the respiratory performance was followed by the negative inspiratory force. The outcome in this case showed that Fentanyl Patch is a reliable, favorable, safe and non-invasive method that produces a good analgesic effect and positive impaction on the post-extubation course of respiratory performance with a satisfactory outcome and no side effects.

Effect of transdermal fentanyl patches on the motility of the sphincter of oddi

BACKGROUND/AIMS

Pain is one of the most troublesome symptoms of pancreatitis. Transdermal fentanyl patches (TFPs) are long-acting analgesics with a reduced risk of dependency. This prospective study evaluated the effect of TFPs on sphincter of Oddi (SO) motility for the management of pain in pancreatitis.

METHODS

SO manometry (SOM) was performed using triple-lumen catheters anterogradely inserted through the percutaneous transhepatic route during cholangioscopy in 16 patients. The basal pressure, amplitude, and frequency of the SO were assessed before and after applying a TFP at 24 hour at doses of 25 and 12.5µg/hr, respectively.

RESULTS

Two of 16 patients receiving a 25µg/hr. TFP were excluded because of adverse side effects (headache and/or nausea). The mean basal pressure, amplitude, and frequency of SOM did not change significantly in the 25µg/hr TFP group (n=4 patients). Parameters of SO function also did not significantly change in the 12.5µg/hr TFP group (n=11 patients).

CONCLUSIONS

TFPs below a dose of 25µg/hr may not affect the motility of the SO. Administration of TFPs at lower dosages seems to be a safe analgesic treatment for the pain control of patients with pancreatitis without affecting the function of the SO.

Azole antimycotics and drug interactions in the perioperative period

PURPOSE OF REVIEW

A beneficial effect of antifungal prophylaxis on the prevention of invasive fungal infections has increased the use of azole antimycotics in intensive care and during the perioperative period. At the same time more severe illnesses are treated and multiple drug therapies are employed. Thus, the potential for severe drug-drug interactions has increased. Previous studies have shown that azole antimycotics increase the risk of many clinically significant drug interactions with potentially hazardous consequences.

RECENT FINDINGS

A recent pharmacoepidemiological study has found a more than five-fold incidence ratio in the adjusted rate of sudden death from cardiac diseases among those patients who were given simultaneously inhibitors of cytochrome P450 (CYP) enzymes and their substrates. Although new triazole antifungals are well tolerated, they still cause significant inhibition of CYP enzymes.

SUMMARY

This review focuses on azole antimycotics and anesthetic drugs being used during the perioperative period and discusses the possible clinically significant drug-drug interactions. Azole antimycotics are amongst the strongest inhibitors of CYP-mediated drug metabolism. Anesthesiologists must be aware of the interaction potential of azole antimycotics to be able to adjust their perioperative strategies according to the patient's condition and concomitant medication.

Transdermal Opioids for Cancer Pain Management

The prevalence of pain in cancer is up to 90%, more than 45% of this can be adequately managed using the World Health Organisation three step analgesic ladder.Transdermal opioids are safe, effective, and produce significantly fewer side effects than oral morphine when used for moderate to severe cancer pain.Transdermal buprenorphine has a lower incidence of systemic side effects than transdermal fentanyl and it is indicated for use in cancer patients with neuropathic pain and renal dysfunction.Transdermal opioids require a long lag period for dose stabilisation and elimination, hence are unsuitable for acute or unstable pain, and may result in prolonged side effects.Transdermal analgesics reduce the need for frequent dosing, clock watching and are more convenient for patients, physicians and carers, hence increasing treatment compliance.

High-dose fentanyl patch for cancer pain of a patient with cholangiocarcinoma

We describe here a patient who obtained a good analgesic effect with high-dose fentanyl patches for controlling cancer pain. A 52-year-old man was referred to our hospital because of severe cancer pain that was 7/10 on a numeric rating scale (NRS). He had been diagnosed with locally advanced cholangiocarcinoma 3 months previously. We prescribed weak opioids and an antidepressant, but his pain was not relieved. We introduced strong opioids (transdermal fentanyl patches for the background pain and a short-acting opioid for the breakthrough pain) and his pain was tolerable on 250 µg/hr of fentanyl patches for 3 months. With time, however, his pain intensity became worse and this reached up to 8/10 to 9/10 on the NRS. Percutaneous transhepatic biliary drainage was performed, which did not relieve his pain. We increased gradually the dose of transdermal fentanyl to 1,050 µg/hr (20 patches). At this dose, the patient was mentally alert, with good pain control (NRS 2/10 to 3/10) and no exacerbation of side effects. To the best of our knowledge, we report here on the highest dose of transdermal fentanyl that has been successfully used for treating a patient suffering from visceral cancer pain.

Transdermal delivery of fentanyl from matrix and reservoir systems: effect of heat and compromised skin

The United States Food and Drug Administration (FDA) has received numerous reports of serious adverse events, including death, in patients using fentanyl transdermal systems (FTS). To gain a better understanding of these problems, the current research focuses on the in vitro characterization of fentanyl reservoir (Duragesic) and matrix (Mylan) systems with respect to drug release and skin permeation under conditions of elevated temperature and compromised skin. In addition, different synthetic membrane barriers were evaluated to identify the one that best simulates fentanyl skin transport, and thus may be useful as a model for these systems in future studies. The results indicate that reservoir and matrix FTS are comparable when applied to intact skin at normal skin temperature but the kinetics of drug delivery are different in the two systems. At 40 degrees C, the permeation rate of fentanyl was twice that seen at 32 degrees C over the first 24 h in both systems; however, the total drug permeation in 72 h is significantly higher in the reservoir FTS. When applied to partially compromised skin, matrix FTS has a greater permeation enhancement effect than reservoir FTS. The intrinsic rate limiting membrane of the reservoir system served to limit drug permeation when the skin (barrier) permeability was compromised. Different ethylene vinyl acetate membranes were shown to have fentanyl permeability values encompassing the variability in human skin. Results using the in vitro model developed using synthetic membranes suggest that they mimic the effect of compromised skin on fentanyl permeability. Especially for highly potent drugs such as fentanyl, it is important that patients follow instructions regarding application of heat and use of the product on compromised skin.