Treatment of cancer pain with transdermal fentanyl

Opioid rotation from transdermal fentanyl to continuous subcutaneous hydromorphone in a cachectic patient: A case report and review of the literature

Opioid rotation from transdermal fentanyl to an alternate opioid is often necessitated in advanced disease, but is fraught with uncertainty due to variable absorption from the patch in end-stage illness and the lack of a clearly established opioid rotation ratio. The manufacturer of transdermal fentanyl provides opioid rotation recommendations only for rotation from the oral morphine equivalent daily dose (MEDD) of opioid to the patch, not in the opposite direction. This is a case report of a single patient with cancer and cachexia admitted to the palliative care unit of a large academic medical centre in Canada. The patient is a 50-year-old female with widely metastatic breast cancer who developed opioid toxicity when maintenance transdermal fentanyl patch therapy (100 μg patch applied every 72 h) was rotated to subcutaneous hydromorphone infusion to improve pain control. Hydromorphone was initiated at a rate of 1 mg/h by continuous infusion based on an opioid rotation ratio for transdermal fentanyl (μg/h):MEDD (mg/day) of 1:2.4. Opioid toxicity eventually resolved with downward titration of hydromorphone to only 30% of the initially estimated equianalgesic dose. This case highlights the need for close follow-up of all patients undergoing opioid rotation from transdermal fentanyl and reinforces the need to reduce the initial dose of the new opioid by 30%-50% of the calculated MEDD, especially when rotating from a high dose of transdermal fentanyl, or if there are factors potentially impairing absorption from the patch such as age, cachexia and weight loss, or if rotation is performed for reasons other than uncontrolled pain.

Evaluation of Heat Effects on Transdermal Nicotine Delivery In Vitro and In Silico Using Heat-Enhanced Transport Model Analysis

A combined experimental and computational model approach was developed to assess heat effects on drug delivery from transdermal delivery systems (TDSs) in vitro and nicotine was the model drug. A Franz diffusion cell system was modified to allow close control of skin temperature when heat was applied from an infrared lamp in vitro. The effects of different heat application regimens on nicotine fluxes from two commercial TDSs across human cadaver skin were determined. Results were interpreted in terms of transport parameters estimated using a computational heat and mass transport model. Steady-state skin surface temperature was obtained rapidly after heat application. Increasing skin surface temperature from 32 to 42°C resulted in an approximately 2-fold increase in average nicotine flux for both TDSs, with maximum flux observed during early heat application. ANOVA statistical analyses of the in vitro permeation data identified TDS differences, further evidenced by the need for a two-layer model to describe one of the TDSs. Activation energies associated with these data suggest similar temperature effects on nicotine transport across the skin despite TDS design differences. Model simulations based on data obtained from continuous heat application were able to predict system response to intermittent heat application, as shown by the agreement between the simulation results and experimental data of nicotine fluxes under four different heat application regimens. The combination of in vitro permeation testing and a computational model provided a parameter-based heat and mass transport approach to evaluate heat effects on nicotine TDS delivery.

Modeling Temperature-Dependent Dermal Absorption and Clearance for Transdermal and Topical Drug Applications

A computational model was developed to better understand the impact of elevated skin temperatures on transdermal drug delivery and dermal clearance. A simultaneous heat and mass transport model with emphasis on transdermal delivery system (TDS) applications was developed to address transient and steady-state temperature effects on dermal absorption. The model was tested using representative data from nicotine TDS applied to human skin either in vitro or in vivo. The approximately 2-fold increase of nicotine absorption with a 10°C increase in skin surface temperature was consistent with a 50-65 kJ/mol activation energy for diffusion in the stratum corneum, with this layer serving as the primary barrier for nicotine absorption. Incorporation of a dermal clearance component into the model revealed efficient removal of nicotine via the dermal capillaries at both normal and elevated temperatures. Two-compartment pharmacokinetic simulations yielded systemic drug concentrations consistent with the human pharmacokinetic data. Both in vitro skin permeation and in vivo pharmacokinetics of nicotine delivered from a marketed TDS under normal and elevated temperatures can be satisfactorily described by a simultaneous heat and mass transfer computational model incorporating realistic skin barrier properties and dermal clearance components.

Transdermal Fentanyl as A Front-Line Approach to Moderate-Severe Pain: A meta-analysis of Randomized Clinical Trials

Objective: The safety of transdermal fentanyl (TF) in comparison with slow-release oral morphine (SROM) in moderate-severe pain was assessed. Design: A systematic review of the literature was performed to identify all randomized trials comparing TF and SROM in moderate-severe pain. Overall safety was the primary end point. Trials enrolling both cancer and non-cancer patients were included in the analysis. Heterogeneity was assessed using the Mantel-Haenszel test; a random effects model was used for the pooled analysis. Cumulative and distinctive analyses for cancer and non-cancer pain were performed whenever the outcome was reported in at least two trials. Results: Five trials met the inclusion criteria. A significant advantage of TF was documented for constipation, laxative use, and urinary retention. TF was preferred by cancer and non-cancer patients. A difference in favour of SROM was documented for nausea, diarrhea, and sweating in cancer and non-cancer patients. No differences were observed for the other items considered. Conclusions: TF and SROM seem to have a different side effects profile, and TF seems to be preferred by patients. The hierarchical approach traditionally recommended by the main scientific societies (oral morphine and then TF) could be replaced by a front-line approach based on patients’ characteristics and needs.

Do laws impact opioids consumption? A breakpoint analysis based on Italian sales data

Purpose

In Italy, where the adoption of opioid analgesics in pain management has been historically poor, an increase in opioids consumption occurred between 2000 and 2015. The aim of this study is to assess, through specific time series analyses for trend changes, the impact of different intervening factors – such as the availability of new drugs, the observance of clinical guidelines, changes in prescription regulations, and in reimbursement policies – on opioids sales to community pharmacies in Italy, focusing on the time period 2000–2010.

Materials and methods

Five opioids were considered: codeine, tramadol, buprenorphine, morphine, and fentanyl. The analysis is based on sales data collected at wholesale distributors. For each one of the five drugs, time series of the number of Defined Daily Doses per thousand inhabitants per day in the period 2000–2010 were analyzed, and an estimation of breakpoints was performed using segmented linear regression.

Results

Drug sales underwent a sharp increase in 2000–2010, although on different scales. Segmented regression analysis highlighted different potential breakpoints, corresponding to either a significant change in value and/or in slope. Sales of the five opioids were affected by at least one relevant event, often due to a synergy of regulatory, marketing, and technological factors. The effect of reimbursement changes has proved important.

Conclusion

Between 2000 and 2010, regulatory, technological, and reimbursement changes significantly influenced opioid sales to community pharmacies in Italy. The sales of relatively new drug products seem to be less influenced by changes in reimbursement and regulatory policies than that of more established products, suggesting that physicians are more comfortable with “old” drugs, since their clinical use is supported by established clinical guidelines and protocols.

Extended-release of opioids using fentanyl-based polymeric nanoparticles for enhanced pain management

Fentanyl-terminated polyesters provide linear release of therapeutics with an effective antinociceptive effect in vivo.

Poor adhesion of fentanyl transdermal patches may mimic end-of-dosage failure after 48 hours and prompt early patch replacement in hospitalized cancer pain patients

Context

Renewal of fentanyl transdermal patch (transdermal therapeutic system [TTS]) should occur every 3 days (72 hours) according to manufacturer’s guidelines. Some studies mentioned patients reporting end-of-dose failure, and thus, some authors recommend shortening the interval of application to 2 days (48 hours). However, reasons for early replacement are mostly unknown.

Objectives

The objectives of this study were to assess the prevalence of early replacement of fentanyl TTS in a cancer center in Basel, Switzerland, and to assess the reasons for early replacement in stationary patients.

Methods

We retrieved all fentanyl TTS administered in a cancer center in Basel, Switzerland, between November 11, 2011, and January 31, 2015, from the electronic medical database.

Results

A total of 739 patients (mean age 71.4±11.5 years, 55% women) were administered 2,250 fentanyl TTS (dosage 6–500 µg/hour). Most replacements occurred after 72 hours (61.6%) and a few after 48 hours (7.4%). Patients with early replacement after 48 hours were significantly younger (63.8 years versus 71.5 years, p<0.001) and obtained higher mean dosages of fentanyl TTS (89 µg/hour versus 44.1 µg/hour, p<0.001) and rescue medication (calculated as oral morphine equivalent in milligrams: 185.1 mg versus 39.6 mg during the first 24 hours after replacement, p<0.001). No pharmacological rationale for early replacement was observed. According to 57 physicians, nurses, and pharmacists, the most often reasons for early TTS replacement were end-of-dosage pain (41.4%) and poor adhesion (31.4%).

Conclusion

In the absence of any physiological, pharmacological, or environmental reasons recorded in the database to explain an early replacement of fentanyl TTS, skin adhesion problems may point practical reasons and mimic end-of-dosage failure.

Drug use evaluation of transdermal fentanyl in a tertiary hospital

Objectives

The primary objective of the study was to assess the rationale of fentanyl patch initiation and continuation for pain. The secondary objectives were to analyse prescribing pattern between disciplines, monitoring criteria and adverse events profile of fentanyl patch in the inpatient wards for a tertiary hospital.

Methods

A retrospective case series review was undertaken of patients who received transdermal fentanyl for pain from April to June 2013 at the National University Hospital, Singapore. Relevant data were collected from electronic and physical medical records and audit criteria applied for indication, opioid tolerance, dosage regimen, adverse events and monitoring criteria.

Results

40 patients were prescribed fentanyl patches for pain in the study period. 15 patients (62.5%) had one or more problems during initiation of fentanyl patch. Appropriate use during initiation was low with only 9 (38%) patients meeting all the required criteria. Most of the inappropriate use involved a lack of bridging opioids (58%), wrong opioid conversion dose (42%) and use in opioid-naïve patients (42%). In addition, three cases of inappropriate placement were observed. Monitoring for efficacy and adverse effects generally met audit criteria. There was a low incidence of discontinuation (21%) due to its well-tolerated side effect profile.

Conclusions

This study highlighted high incidence of inappropriate initiation of fentanyl patch, and we proposed an in-house guideline to aid physicians in initiating fentanyl patches during admission and to educate nursing staff of the monitoring parameters for efficacy and toxicity.

Efficacy and safety of transdermal fentanyl for the treatment of oral mucositis pain caused by chemoradiotherapy in patients with esophageal squamous cell carcinoma

PURPOSE

Oral mucositis is one of the most painful side effects found in esophageal squamous cell carcinoma (ESCC) patients treated with chemoradiotherapy. The transdermal route of administration is worthy of investigation for patients who suffer from dysphagia due to severe oral mucositis. In this phase 2 study, we investigated the efficacy and safety of transdermal fentanyl (TDF) for mucositis pain caused by chemoradiotherapy in ESCC patients.

METHODS

Forty-six ESCC patients who experienced moderate to severe oral mucosal pain during chemoradiotherapy received TDF for pain relief. The assessment of pain was made according to the Numeric Rating Scale (NRS). Efficacy and safety of TDF was collected and conducted in an open-label fashion. The analgesic effect, quality of life, and side effects were evaluated after the administration of transdermal fentanyl using the paired sample Wilcoxon signed rank test.

RESULTS

The mucositis-induced pain disappeared in 31 (67.4 %) patients during the treatment with transdermal fentanyl with the median time of onset at day 6.6 (range 3-14). The median Numeric Rating Scale (NRS) score was reduced from 6 (range 3-9) before treatment to 4.5 (range 2-9), 3 (range 2-8), 2.5 (range 1-8), 2 (range 0-6), and 0 (range 0-4) on days 3, 6, 9, 11, and 15, respectively, after treatment (P < 0.001). The patients' quality of life also improved significantly (P < 0.01). The side effects of treatment were mild and disappeared within several days.

CONCLUSION

Transdermal fentanyl is an effective, convenient, and well-tolerated treatment for mucositis pain caused by chemoradiotherapy, which can improve ESCC patients' quality of life.

Reduced morphine consumption and pain severity with transdermal fentanyl patches following total knee arthroplasty

PURPOSE

To determine the effects of transdermal fentanyl patches (TFPs) for postoperative analgesia in patients undergoing total knee arthroplasty (TKA) surgery.

METHODS

A randomized, double-blind, controlled trial study of 40 ASA I-III patients undergoing TKA surgery was performed under general anaesthesia. Patients were randomly divided into two groups. Group I (n = 20) received two 25 μg TFPs placed on the laterals of chest wall approximately 12 h before induction of general anaesthesia. Group II, the control group (n = 20), received placebo patches of identical size. Postoperative pain at rest was assessed with visual analogue scale (VAS) at 0, 30 min and 2, 4, 6, 12, 24, 48 and 72 h. Total rescue consumption of morphine was estimated with patient control analgesia during the first 72 h after operation. The degree of active knee flexion and incidence of side effects were also evaluated.

RESULTS

The VAS scores at 2, 4, 6, 12, 24, 48 and 72 h were significantly less in the group I compared to the group II (p < 0.05). Total morphine consumption was significantly less in group I than in group II (p < 0.05). No significant differences were found between the groups in the postoperative active knee flexion (n.s.). Side effects were similar between the groups.

CONCLUSIONS

Transdermal fentanyl patches provide effective pain relief and decrease total rescue morphine consumption during the first 72 h after operation without additive side effects in patients undergoing TKA surgery.

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.

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.

Use of opioid analgesics in the treatment of cancer pain: evidence-based recommendations from the EAPC

Here we provide the updated version of the guidelines of the European Association for Palliative Care (EAPC) on the use of opioids for the treatment of cancer pain. The update was undertaken by the European Palliative Care Research Collaborative. Previous EAPC guidelines were reviewed and compared with other currently available guidelines, and consensus recommendations were created by formal international expert panel. The content of the guidelines was defined according to several topics, each of which was assigned to collaborators who developed systematic literature reviews with a common methodology. The recommendations were developed by a writing committee that combined the evidence derived from the systematic reviews with the panellists' evaluations in a co-authored process, and were endorsed by the EAPC Board of Directors. The guidelines are presented as a list of 16 evidence-based recommendations developed according to the Grading of Recommendations Assessment, Development and Evaluation system.

Is oral morphine still the first choice opioid for moderate to severe cancer pain? A systematic review within the European Palliative Care Research Collaborative guidelines project

The aim of this systematic review was to evaluate the evidence that oral morphine can be recommended as the first choice opioid in the treatment of moderate to severe cancer pain in updating the European Association for Palliative Care opioid recommendations. A systematic literature review was performed to update the 2007 Cochrane review 'Oral morphine for cancer pain'. The literature search was conducted on MedLine, EMBASE and Cochrane Central Register of Controlled Trials databases. The search strategy, limited in time (from 1 July 2006 to 31 October 2009), was aimed to be as extensive as possible using both text words and MeSH/EMTREE terms; a hand search of the reference lists of identified papers was also performed. Randomized clinical trials, containing data on efficacy and/or side effects of morphine, were identified. Among the papers retrieved from the cited databases and the Cochrane review, 17 eligible studies, for a total of 2053 patients, and a meta-analysis were selected. These studies do not add significant information to the previous Cochrane review confirming the limitation of efficacy and tolerability data on opioid-naïve and non-selected populations of cancer patients treated with morphine and suggesting that oral morphine, oxycodone and hydromorphone have similar efficacy and toxicity in this patient population.

Oral-parenteral conversion factor for morphine in palliative cancer care: a prospective randomized crossover pilot study

Objective. This pilot study clinically tests whether a conversion factor of 2 to 1 is appropriate when changing from oral to parenteral morphine administration in the treatment of cancer-related nociceptive pain and calculates the size of an adequately powered future study. Methods. Eleven outpatients with incurable cancer and well-controlled nociceptive pain were randomly assigned to either intravenous or subcutaneous morphine using half the previous oral 24-hour dose. Each group crossed over after the first three-day period. Serum concentrations of morphine and its metabolites were monitored as well as intensity of pain. Results. Oral to subcutaneous and oral to intravenous quotas of morphine concentrations were approximately 0.9. Subcutaneous to intravenous morphine quotas were 1. Conclusions. The conversion factor of 2 to 1 seems to be a reasonable average but with an obvious need for individual adjustments. Concurrent medications and substantially higher doses of morphine could potentially affect the appropriate conversion factor. An adequately powered study to validate these findings would need at least 121 patients.

Transdermal fentanyl: pharmacology and toxicology

OBJECTIVE

To evaluate the underlying pharmacology, safety, and misuse/abuse of transdermal fentanyl, one of the cornerstone pharmacotherapies for patients with chronic pain.

METHODS

Literature was identified through searches of Medline (PubMed) and several textbooks in the areas of pharmacology, toxicology, and pain management. A bibliographical review of articles identified by these searches was also performed. Search terms included combinations of the following: fentanyl, transdermal, patch, pharmacology, kinetics, toxicity, and poisoning. All pertinent clinical trials, retrospective studies, and case reports relevant to fentanyl pharmacology and transdermal fentanyl administered by any route and published in English were identified. Each was reviewed for data regarding the clinical pharmacology, abuse, misuse, and safety of transdermal fentanyl. Data from these studies and information from review articles and pharmaceutical prescribing information were included in this review.

RESULTS

Fentanyl is a high-potency opioid that has many uses in the treatment of both acute and chronic pain. Intentional or unintentional misuse, as well as abuse, may lead to significant clinical consequences, including death. Both the US Food and Drug Administration (FDA) and Health Canada have warned of potential pitfalls associated with transdermal fentanyl, although these have not been completely effective in preventing life-threatening adverse events and fatalities related to its inappropriate use.

CONCLUSIONS

Clinically consequential adverse effects may occur unexpectedly with normal use of transdermal fentanyl, or if misused or abused. Misuse and therapeutic error may be largely preventable through better education at all levels for both the prescriber and patient. The prevention of intentional misuse or abuse may require regulatory intervention.

A One Year Health Economic Model Comparing Transdermal Fentanyl with Sustained-Release Morphine in the Treatment of Chronic Noncancer Pain

A Markov model was constructed to simulate the resource use and health outcomes of one year of treatment comparing the fentanyl transdermal therapeutic system (fentanyl-TTS) with oral sustained-release (SR) morphine in outpatients with noncancer pain in Denmark. Effectiveness was assessed in terms of days of good pain control and days on initial treatment. Costs included those of baseline pain management, including breakthrough pain; co-medication costs; and control of adverse events. Fentanyl-TTS was more effective than SR-morphine in achieving good pain control (99 vs. 64 days, respectively) and the incremental cost-effectiveness of fentanyl-TTS was US dollars 10.26 per extra day of good pain control. Patients treated with fentanyl-TTS remained considerably longer on initial treatment compared with those treated with SR-morphine (166 days vs. 117 days, respectively). The results of this study suggest that fentanyl-TTS is a competitive therapeutic and economic choice for the treatment of chronic noncancer pain.

Cancer-related pain and quality of life in prostate cancer patients: assessment using the Functional Assessment of Prostate Cancer Therapy

The objective of this study was to assess disease-associated pain and quality of life (QOL) in patients with prostate cancer (PC). A total of 102 PC patients (clinical stage B, C: 20, D2: 82) patients were enrolled. QOL was assessed using the Functional Assessment of Cancer Therapy, General and Prostate (FACT-G/P). Disease-specific pain response was assessed using the visual analog scale and the face rating scale. In patients with stage D2 PC, mean age, serum prostate-specific antigen level, and performance status were 72.5 +/- 7.1 years (range, 55-88), 217 +/- 467 ng/mL (range, 0.1-2600), and 1.4 (0-4), respectively. The score of physical well-being and FACT-P was significantly lower in stage D2 patients, compared with those of stage B/C (P = 0.02, 0.0088, respectively). Performance status, extent of disease, and the visual analog scale were related with a poor QOL score (P = 0.0054, 0.01, <0.0001, respectively). Thirty-two patients (39%) had disease-specific pain, and 25 patients received a related treatment. Ten patients under morphine analgesics maintained better QOL in almost all domains, compared with the seven patients without any painkillers. Combined use of FACT and pain scales enhances the objective assessment of QOL and pain status in PC patients. Control of disease-associated pain is crucial to improving QOL in stage D2 PC patients.

Efficacy and safety of transdermal fentanyl for treatment of oral mucositis pain caused by chemotherapy

BACKGROUND/OBJECTIVE

We investigated the efficacy and safety of transdermal fentanyl for severe mucositis pain caused by chemotherapy.

METHODS

Thirty-two patients who had moderate to severe pain using the Numeric Rating Scale (NRS) were enrolled in this study. The analgesic effect, quality of life and side effects were evaluated after the administration of transdermal fentanyl.

RESULTS

The median NRS score was reduced from 6 (range 4 - 9) before treatment to 4 (range 0 - 9), 2.5 (range 0 - 8), 2 (range 0 - 8), 2 (range 0 - 6) and 0 (range 0 - 5) on days 3, 5, 7, 10 and 15, respectively, after treatment (p < 0.001). The patients' quality of life also improved significantly (p < 0.01). The side effects of treatment were mild, and disappeared within several days.

CONCLUSIONS

Transdermal fentanyl is an effective, convenient and well-tolerated treatment for severe mucositis pain caused by chemotherapy that can improve patients' quality of life.

Pain therapy

Cancer-related pain is a major issue of healthcare systems worldwide. The reported incidence, considering all stages of the disease, is 51%, which can increase to 74% in the advanced and terminal stages. For advanced cancer, pain is moderate to severe in about 40-50% and very severe or excruciating in 25-30% of cases. Pain is both a sensation and an emotional experience. Pain is always subjective; and may be affected by emotional, social and spiritual components thus it has been defined as "total pain". From a pathophysiological point of view, pain can be classified as nociceptive (somatic and visceral), neuropathic (central, peripheral, sympathetic) idiopathic or psychogenic. A proper pain assessment is fundamental for an effective and individualised treatment. In 1986 the World Health Organisation (WHO) published analgesic guidelines for the treatment of cancer pain based on a three-step ladder and practical recommendations. These guidelines serve as an algorithm for a sequential pharmacological approach to treatment according to the intensity of pain as reported by the patient. The WHO analgesic ladder remains the clinical model for pain therapy. Its clinical application should be employed only after a complete and comprehensive assessment and evaluation based on the needs of each patient. When applying the WHO guidelines, up to 90% of patients can find relief regardless of the settings of care, social and/or cultural environment. This is the standard treatment on a type C basis. Only when such an approach is ineffective are interventions such as spinal administration of opioid analgesics or neuroinvasive procedures recommended.

Morphine bioavailability from a topical gel formulation in volunteers

Although available therapies provide relief to many patients with cancer-related pain, swallowing difficulties or intestinal obstruction may preclude oral analgesic delivery in some. Topical morphine might provide an alternate delivery form but morphine bioavailability from a topical gel formulation has not been reported in humans. We conducted a randomized, placebo-controlled, double-blind, crossover study of five volunteers after they provided institutionally-approved, written, informed consent. They were admitted to the Northwestern University General Clinical Research Center twice, being randomly assigned to receive either 1mL of morphine compounded at 10mg/mL in pluronic lecithin organogel (PLO) base applied to the wrist and 1mL of normal saline administered subcutaneously, or 1mL of topical drug-free PLO base and 1mL of subcutaneous morphine, 3mg/mL, the first time and the opposite combination the second. Seventeen blood samples were collected from 5minutes to 10hours after dose administration for morphine concentration determination. Plasma samples were prepared by solid-phase extraction and morphine concentrations measured by a mass spectrometric technique with a linear range of 0.5-500ng/mL. Bioavailability of the topical formulation relative to the subcutaneous dose was to be estimated from doses and the plasma morphine concentration versus time relationships. Because morphine was seldom detected in plasma samples after topical administration and was unquantifiable when it was, the low bioavailability of topical morphine was unquantifiable. These results suggest that topical administration of morphine compounded in a PLO base for transdermal drug delivery is unlikely to provide relief of cancer-related pain.

Ex vivo evaluation of bioadhesive films for buccal delivery of fentanyl

The goals of this work were (i) to develop bioadhesive films for the buccal delivery of fentanyl, and (ii) to evaluate their performance in vitro using the pig esophageal model. Films were made with polyvinylpyrrolidone (PVP) of two different molecular weights: PVP K30 and PVP K90. Delivery of fentanyl was determined across full-thickness mucosa and across heat-separated epithelium (where the permeability barrier was shown to be located). The influence of film pH was investigated, and it was found that fentanyl permeation increased with increasing pH (i.e., when a higher percentage of the unionized fraction of drug was present). However, at the pH values studied, fentanyl was predominantly ionized suggesting that transport pathways offering a hydrophilic, or polar, environment across the mucosa were available. The transport rates achieved from the PVP films providing the highest delivery suggest that a buccal system of only 1-2 cm(2) in surface area could achieve a therapeutic effect equivalent to a 10 cm(2) transdermal patch, with a much shorter lag-time.

Clinical experience with transdermal and orally administered opioids in palliative care patients--a retrospective study

BACKGROUND

Transdermal fentanyl is a widely used opioid for the treatment of cancer pain. Simplicity of use and high patient compliance are the main advantages of this opioid. However, based on our clinical experience, transdermal fentanyl is often not efficacious in terminally ill palliative care patients. We thus retrospectively examined the pain management and need for opioid switching in cancer patients admitted to our palliative care unit.

METHODS

Of 354 patients admitted to our palliative care unit from 2004 through 2005, 81 patients were pre-treated with transdermal fentanyl. Demographic and cancer-related data (diagnosis, symptoms, pain score on a numeric rating scale (NRS)), analgesic dose at admission and discharge were compared.

STATISTICS

mean +/- SD, ANOVA, Wilcoxon's test was used for inter-group comparisons, significance P < 0.05, adjusted for multiple testing. Pain scores are given in median (range).

RESULTS

Mean transdermal fentanyl dose at admission was 81.0 +/- 55.8 microg/h. In 79 patients transdermal fentanyl treatment was discontinued. In two patients, analgesic treatment according to WHO I provided sufficient pain relief. The other 77 patients were switched to other opioids: 33 patients to oral morphine and 44 to oral hydromorphone. In patients switched to morphine the dose at discharge (104.7 +/- 89.0 mg) was lower than at admission (165.5 mg morphine equivalence). In patients switched to hydromorphone the dose of 277.8 +/- 255.0 mg morphine equivalent was higher at discharge than at admission (218.2 +/- 131.4 mg morphine equivalence--considering an equianalgesic conversion ratio morphine: hydromorphone = 7.5: 1). Pain scores decreased significantly after opioid rotation (NRS at rest/on exertion: 4 (0-10)/7 (2-10) versus 1 (0-3)/2 (0-5); P < 0.001).

CONCLUSIONS

In the patient group switched to morphine, sufficient pain relief was achieved by lower equianalgesic morphine doses, compared with the doses at admission. In the patient group switched to hydromorphone, higher equianalgesic morphine doses were needed at discharge, considering an equianalgesic conversion ratio of morphine: hydromorphone = 7.5: 1. Patients with far advanced cancer often suffer from sweating and cachexia, which may have negative effects on the absorption of transdermal fentanyl. Opioid switching to oral morphine or hydromorphone was well tolerated and proved to be an efficacious option for cancer pain treatment.

Transdermal fentanyl in childhood and adolescence: a comprehensive literature review

The recently introduced fentanyl transdermal therapeutic system (TTS) with a drug release rate of 12.5 microg/h matches the lower dosing requirements of cancer pain control in children. It is likely that fentanyl TTS will be used in pediatrics with increasing frequency. We compiled the published evidence on pediatric applications of this drug formulation to help physicians get the most benefit from its use. Within this systematic review, a total of 11 observational clinical or pharmacokinetic studies were identified. There are no pediatric randomized or controlled cohort studies. Pharmacokinetic studies poorly described time-concentration profiles after application. The time to reach steady-state serum drug concentrations seems to be longer, clearance (expressed as liters per kilogram per hour) higher, and elimination half-life shorter in children than in adults. There are no fundamental differences in effect or profile of adverse effects compared with adults. Fentanyl TTS may be associated with less constipation compared with morphine use. Frequently, pediatric patients need supplemental mechanical fixation of the fentanyl TTS by means of medical tape. Younger patients tend to have a higher fentanyl requirement when referenced to body weight. Both parents and medical professionals are satisfied with fentanyl TTS to a higher degree than with individual analgesic pretreatment regimens. Fentanyl TTS is a promising option for chronic pain control in children. An approximate conversion factor of 45 mg/day oral morphine to 12.5 microg/h fentanyl TTS is used for initial therapy dose estimation in children receiving long-term morphine therapy. This is conservatively low to avoid respiratory depression. Daily oral morphine equivalent dose should be at least 30 mg/d before fentanyl TTS therapy is started with 12.5 microg/h. Evidence for superiority of fentanyl TTS treatment above conventional opioid administration is both scarce and of low quality.

PERSPECTIVE

The article gives a comprehensive overview of all pediatric data concerning the fentanyl TTS. Children may take longer to reach steady-state fentanyl serum concentrations than adults, and younger children may require higher doses referenced to body weight than older children or adults. Consequently, there is a need to provide sufficient medication in the phase of therapy initiation to prevent breakthrough pain. The 72-hour dosing schedule recommended by the manufacturers may not be applicable to children because of poor patch adhesiveness. The authors suggest to ensure firm fixation of the fentanyl TTS with additional medical tape if necessary and to change the fentanyl TTS after 48 hours. Transdermal fentanyl in children may exhibit fewer side effects when compared with other opioids, especially constipation. Randomized studies are urgently needed to definitively answer this question.

Withdrawal symptoms from transdermal fentanyl (TDF) after an allogeneic peripheral blood stem cell transplant (PBSCT)

A 47-year-old woman who underwent allogenic peripheral blood stem cell transplant developed withdrawal symptoms soon after Fentanyl 25 mcg/h patch was stopped, which has not been reported at this dose. Possible causes, such as the inhibition of CYP3A4 induced by cyclosporine causing elevations of serum fentanyl, are discussed.

Inter- and intraindividual variabilities in pharmacokinetics of fentanyl after repeated 72-hour transdermal applications in cancer pain patients

Perception of pain by the patient is frequently one of the early signs preceding a diagnosis of cancer and, later, a sinister sign of disease progression. Among opioid drugs, transdermal fentanyl has been evaluated in the treatment of moderate to severe cancer pain. The objective of this study was to investigate the intra- and interindividual variabilities in pharmacokinetics after fentanyl drug delivery by the transdermal fentanyl patch delivery system in patients with cancer pain. As a first step, a liquid chromatography-mass spectrometry method was developed for the determination of the analgesic fentanyl in human plasma. This method was validated over the concentration range 0.15-100 ng/mL. The study group consisted of 29 inpatients (18 men and 11 women; age range 29-80 years). The initial transdermal fentanyl delivery rate was chosen depending on the patient's analgesic requirements. For 20 patients, the initial TTS fentanyl delivery rate was 25 or 50 microg/h. For 6 patients, the initial delivery rate was 75-150 microg/h. Two patients received up to 300 microg/h fentanyl delivery rate, and 3 patients received up to 350 microg/h fentanyl delivery rate. Fifteen of the 29 patients received rescue doses of subcutaneous or oral morphine, and 26 patients received paracetamol with codeine (30 mg per os). Blood samples were collected at the following intervals: 2-5, 22-26, or 45-47 hours following fentanyl patch application. The severity of pain experienced by the patient was assessed thrice daily using a visual analogue scale. The study period was 46 days. Large patient-to-patient variations in pharmacokinetic parameters occurred, although intraindividual variability was limited. A mean bioavailability of 78% was estimated; the total clearance averaged 41 L/h. From 25 to 100 mug/h fentanyl delivery rate, the pharmacokinetics was linear. At the 2 highest doses, an increase of total clearance was observed (>60 L/h). For the whole group, transdermal fentanyl treatment provided good to excellent pain relief in the majority of patients.

Opioids in pain management of blood-related malignancies

Opioids are basic analgesics used in the treatment of moderate to severe pain in patients affected by blood-related malignancies. They should be sequentially administered according to the World Health Organisation scale for cancer pain. Initial treatment and titration with opioids should be based on immediate-release preparations, to be administered at appropriate intervals in order to relieve pain and to satisfy the individual opioid requirement. Once a relatively good pain control has been achieved, a slow release formulation at equivalent doses can be given. Most patients can be adequately managed using oral formulation opioids. However, a small group, such as those presenting severe mucositis or requiring a rapid pain relief, should be managed by intravenous continuous infusion and/or by a patient-controlled analgesia system; while for patients in the community, there are distinct advantages to using the subcutaneous route. Other available routes of administration for opioids, can be used in selected circumstances, including rectal, transdermal, epidural, intrathecal and intramuscular. The invasive neuraxial route has a very limited role in patients with haematological malignancies, given the high risk of infection and bleeding. Through a close observation and a careful management, opioid-related side effects can be effectively prevented and treated. This article reviews the principles of opioid therapy and how opioids can be adapted for patients with pain due to haematological malignancies.

Severe deficit in brain reward function associated with fentanyl withdrawal in rats

BACKGROUND

During the last decade, there has been a strong increase in the use of the mu-opioid receptor agonist fentanyl. The aim of these studies was to investigate the effects of fentanyl withdrawal on brain reward function and somatic withdrawal signs.

METHODS

Fentanyl and saline were chronically administered via minipumps. An intracranial self-stimulation procedure was used to provide a measure of brain reward function. Somatic signs were recorded from a checklist of opioid abstinence signs.

RESULTS

The opioid receptor antagonist naloxone induced a dose-dependent elevation in brain reward thresholds and somatic withdrawal signs in fentanyl-treated rats. Discontinuation of fentanyl administration resulted in a time-dependent elevation of brain reward thresholds and somatic withdrawal signs.

CONCLUSIONS

These findings indicate that fentanyl withdrawal is associated with affective and somatic withdrawal signs. The severity of the deficit in brain reward function in this animal model suggests that affective fentanyl withdrawal symptoms may be a strong deterrent to abstinence.

Is the use of transdermal fentanyl inappropriate according to the WHO guidelines and the EAPC recommendations? A study of cancer patients in Italy

BACKGROUND

World Health Organization (WHO) guidelines, Agency for Health Care Policy and Research (AHCPR) clinical practice guidelines, and EAPC recommendations indicate oral route of opioid administration as the preferred route. Transdermal administration of opioids is considered an alternative when patients cannot take medications orally. Moreover, WHO and EAPC indicate orally administered morphine as the first-choice drug for the treatment of moderate to severe cancer-related pain. However, we can see that in Italy there is an increasing use of transdermal fentanyl (TF) as first-choice strong opioid (and route) even when oral administration of opioids is possible.

AIMS

The aims of this study are to describe the modality in the use of TF administration in two settings of care, taking into consideration (1) the drugs previously taken by the patients, (2) the reasons for switching from any drug to TF, (3) the conversion ratio used, and (4) the frequency of "inappropriate use of transdermal fentanyl according to the WHO guidelines and the EAPC recommendations", i.e., switching to fentanyl patch from any drug, even if there were no contraindications in using oral morphine. The settings of care considered were the out-patient palliative care unit (OP-PCU) and the oncological wards (OWs) of the National Cancer Institute (NCI) of Milan.

PATIENTS AND METHODS

The clinical charts of 98 patients prescribed with and given fentanyl patch for the first time at the NCI of Milan in 2002 were reviewed and the data gathered were grouped according to the administration of fentanyl at the OP-PCU (63 out-patients) or at the OWs (35 in-patients). Summary descriptive statistics and bar and box plots have been used. Fisher two-tailed exact text was applied to test the differences between in- and out-patients.

RESULTS

Before switching to TF, (1) in-patients were more frequently treated with nonsteroidal anti-inflammatory drugs (NSAIDs) and weak opioids (mostly tramadol) in respect to the out-patients (44.1 vs 25.8%) who were mostly treated with oral morphine (48.4 vs 20.6%) (p=0.045), and (2) 88.7% of the out-patients were treated with oral opioids and only 1.6% with parenteral opioids in respect to OWs where 69.7% were on oral opioids and 18.2% on parenteral opioids (p=0.006). In 29% of out-patients and in 53% of in-patients, changing to fentanyl patch was considered as "inappropriate" (p=0.028) according to the WHO guidelines and the EAPC recommendations. No statistically significant differences between the two settings were observed regarding the reasons for switching and the conversion ratio used.

CONCLUSIONS

There is a trend to use fentanyl patch as first-choice strong opioid in cancer patients in situations such as titration phase, in the presence of instable pain, and in the absence of dysphagia or gastrointestinal symptoms where the use of oral morphine is, however, not contraindicated.

Oxymorphone: a review

Oxymorphone (oxymorphone hydrochloride) (14-hydroxy-dihydromorphinone), a semisynthetic mu-opioid agonist, was first approved by the US Food and Drug Administration in 1959. Oxymorphone is considered a more potent opioid than its parent compound, morphine. Recently, an immediate-release and long-acting oral formulation of this drug was developed that makes oxymorphone a new option in treating moderate to severe pain. This article reviews the pharmacodynamics, pharmacology, and clinical efficacy for this new option in treating moderate to severe pain.

Cancer patients’ first treatment episode with opioids: a pharmaco-epidemiological perspective

GOAL

The factors underlying the choice of opioids for cancer patients in primary care are largely unknown. Our aim was to describe cancer patients' first treatment episode with opioids in relation to disease characteristics and clinical course.

PATIENTS AND METHODS

During 1997 and 1998, a population-based cohort of 4,006 incident cancer patients from a Danish county was identified. The patients were followed up from diagnosis to death or until 31 December 2003, and data on their use of opioids were obtained from a prescription database.

MAIN RESULTS

Eventually, 54% of the cancer patients became incident users of opioids. Opioid treatment was initiated close to the diagnosis date in 20% of the patients. Most incident users (57%) were not terminal when they began using opioids, and 44% survived the first treatment episode. Of those who died, 70% received opioids in their terminal phase. The incidence rates of new opioid users were inversely related to the 5-year cancer survival period. A weak opioid was the first choice in 64% of the non-terminal users and in 43% of the terminal ones. No statistically significant differences in opioid use were found between men and women.

CONCLUSIONS

Opioid use in cancer patients was not confined to the terminal course. Treatment with opioids should be viewed as a dynamic condition, with patients shifting between periods of use and non-use. The aggressiveness of the cancer and the presence of metastases were characteristics found to be strong determinants of opioid use.

Safety, Tolerability, and Efficacy of Continuous Transdermal Dopaminergic Stimulation with Rotigotine Patch in Early-Stage Idiopathic Parkinson Disease

Rotigotine is a new dopamine agonist with transdermal patch formulation for the treatment of Parkinson disease. The aim of this study was to investigate safety and efficacy of rotigotine in patients with early-stage Parkinson disease. In this open-label, dose-escalation, safety and efficacy study, 31 patients in the early stages of idiopathic Parkinson disease received rotigotine to a maximum of 18.0 mg/day. Of the 29 patients who completed the 28-day treatment phase, 24 were maintained at the maximum dose level. The drug was well tolerated, and skin reactions were mild. A statistically significant improvement in UPDRS I, II, and III scores was observed from baseline to end of treatment for the 29 subjects who completed the trial. Mean improvement (+/- standard deviation) was -0.41 +/- 0.78 on UPDRS I (P = 0.0078), -2.76 +/- 3.31 on UPDRS II (P = 0.0001), and -4.62 +/- 5.32 on UPDRS III (P < 0.0001). When results were stratified by maximum dose achieved, significant improvements were seen on all 3 subscores for patients achieving the maximum dose. These data suggest that rotigotine is a safe, well-tolerated, and effective treatment for early-stage Parkinson disease.

The Role of Opioids in Cancer Pain Management

Opioids remain an important cornerstone in the treatment of cancer pain. Effective analgesia is obtained in the majority of cancer pain patients with the application of fairly straightforward algorithms using opioids as the main therapy. Many rational treatment algorithms exist. In this tutorial we will describe the role of opioids in the treatment of cancer pain, including a brief overview of cancer pain syndromes, essential aspects of opioid therapy, opioid pharmacology, opioid rotation, properties of the individual opioids, and management of common side effects of opioids.

Treatment of cancer-related pain with transdermal buprenorphine: a report of three cases

Three patients suffering from pain arising from renal and metastasing prostate and breast cancer were successfully treated with transdermal buprenorphine. The three cases demonstrate that transdermal buprenorphine is an easy-to-use and effective therapeutic option for the treatment of advanced cancer pain, that it can also be used in opioid rotation as an alternative after formerly applied steps II or III opioids have failed and that long-term treatment without dose escalation or compromise in tolerability is possible.

Transdermal fentanyl in HSCT patients: an open trial using transdermal fentanyl for the treatment of oral mucositis pain

Fentanyl is a synthetic opioid that can be delivered through a transdermal therapeutic system (TTS). The aim of this study was to assess the efficacy of fentanyl TTS in treating oral mucositis pain in 75 adult hematopoietic stem cell transplant (HSCT) patients. The analysis was based on 62 patients who developed mucositis. Pain control was assessed by the patients using a visual analogue scale (VAS) from day 0 to day +33 after HSCT. Fentanyl TTS was administered at the patient's request. In all, 20 patients did not require fentanyl (group A). The first 22 patients asking for the patch received fentanyl 25 microg/h (group B) and the subsequent 20 patients received 50 microg/h (group C). There were no significant differences in pain relief between groups B and C. The expected effect of a decrease in mean pain score (mean of the VAS scores of all of the patients in the same group each day) following the application of fentanyl TTS was not noted. We can conclude that fentanyl TTS at the doses used in this study may not adequately relieve oral mucositis pain.

Morphine Use for At-Home Cancer Patients in Japan

Recently, many cancer patients have been cared for at home in Japan. Cancer pain control is one of the most important factors for terminal cancer patients to maintain functional lives at home. Morphine has long been the gold standard in the control of cancer pain. This paper examined the present status of the frequency of morphine use and its prescribing route for pain control in cancer patients at home monitored by doctors offering home care medicine in Japan. We reviewed the data based on the replies to questionnaires about morphine use in a textbook edited in 2001 by the doctors supportive of home care medicine nationwide in Japan. 301 (92.9%) among 324 doctors administered morphine for at-home cancer patients. 257 doctors' replies were analyzed as to the prescribed pattern of morphine after excluding data without information on the administration route. The oral administration was most frequently used in 247 (96.1%) doctors and rectal administration was used in 217 (84.4%) doctors, while intravenous injection and epidural infusions were less common. The pattern of morphine administration was similar between doctors who worked at hospitals and clinics, except that doctors who worked at hospitals administered subcutaneously more frequently than doctors who worked at clinics (69.2% in the hospital vs. 39.4% in the clinic setting). This study has revealed that morphine is commonly prescribed to control pain in at-home cancer patients by doctors who support home care medicine in Japan. The restricted administration routes of morphine among the doctors and less prevalent use of the subcutaneous routes in doctors who work at clinics are also shown in the home cancer care setting. These findings might result from mutual relationship between the thought and experience of doctors and clinical characteristics of patients under home care medicine.