Efficacy and safety of fentanyl sublingual spray for the treatment of breakthrough cancer pain: a randomized, double-blind, placebo-controlled study

Opioid analgesics for nociceptive cancer pain: A comprehensive review

Pain is one of the most burdensome symptoms in people with cancer, and opioid analgesics are considered the mainstay of cancer pain management. For this review, the authors evaluated the efficacy and toxicities of opioid analgesics compared with placebo, other opioids, nonopioid analgesics, and nonpharmacologic treatments for background cancer pain (continuous and relatively constant pain present at rest), and breakthrough cancer pain (transient exacerbation of pain despite stable and adequately controlled background pain). They found a paucity of placebo-controlled trials for background cancer pain, although tapentadol or codeine may be more efficacious than placebo (moderate-certainty to low-certainty evidence). Nonsteroidal anti-inflammatory drugs including aspirin, piroxicam, diclofenac, ketorolac, and the antidepressant medicine imipramine, may be at least as efficacious as opioids for moderate-to-severe background cancer pain. For breakthrough cancer pain, oral transmucosal, buccal, sublingual, or intranasal fentanyl preparations were identified as more efficacious than placebo but were more commonly associated with toxicities, including constipation and nausea. Despite being recommended worldwide for the treatment of cancer pain, morphine was generally not superior to other opioids, nor did it have a more favorable toxicity profile. The interpretation of study results, however, was complicated by the heterogeneity in the study populations evaluated. Given the limited quality and quantity of research, there is a need to reappraise the clinical utility of opioids in people with cancer pain, particularly those who are not at the end of life, and to further explore the effects of opioids on immune system function and quality of life in these individuals.

Use of Opioids for Adults With Pain From Cancer or Cancer Treatment: ASCO Guideline

PURPOSE

To provide guidance on the use of opioids to manage pain from cancer or cancer treatment in adults.

METHODS

A systematic review of the literature identified systematic reviews and randomized controlled trials of the efficacy and safety of opioid analgesics in people with cancer, approaches to opioid initiation and titration, and the prevention and management of opioid adverse events. PubMed and the Cochrane Library were searched from January 1, 2010, to February 17, 2022. American Society of Clinical Oncology convened an Expert Panel to review the evidence and formulate recommendations.

RESULTS

The evidence base consisted of 31 systematic reviews and 16 randomized controlled trials. Opioids have primarily been evaluated in patients with moderate-to-severe cancer pain, and they effectively reduce pain in this population, with well-characterized adverse effects. Evidence was limited for several of the questions of interest, and the Expert Panel relied on consensus for these recommendations or noted that no recommendation could be made at this time.

RECOMMENDATIONS

Opioids should be offered to patients with moderate-to-severe pain related to cancer or active cancer treatment unless contraindicated. Opioids should be initiated PRN (as needed) at the lowest possible dose to achieve acceptable analgesia and patient goals, with early assessment and frequent titration. For patients with a substance use disorder, clinicians should collaborate with a palliative care, pain, and/or substance use disorder specialist to determine the optimal approach to pain management. Opioid adverse effects should be monitored, and strategies are provided for prevention and management.Additional information is available at www.asco.org/supportive-care-guidelines.

Improving the Emergency Department Management of Sickle Cell Vaso-Occlusive Pain Crisis: The Role and Options of Sublingual and Intranasally Administered Analgesia

Vaso-occlusive crisis (VOC), characterized by periods of excruciating pain is the most common clinical manifestation of sickle cell disease (SCD), often resulting in emergency room presentation. These patients often experience long wait times in the emergency department before receiving their first dose of analgesia. This delay results from the complexities of the emergency care system. Using the intranasal or sublingual approach to administering analgesia to SCD patients with VOC offers a fast, safe, noninvasive, atraumatic, and easily accessible route of administration which could reduce the time to first dose of analgesia. With the evolving advances in the development and delivery of analgesic medications, providers should be conversant with the nuances of intranasal and sublingual analgesia in the management of acute vaso-occlusive pain crisis. This review explores the pharmacokinetic profiles, dosages, and administration of intranasal and sublingual analgesics with relevance to the SCD population.

Revision of Pharmacological Treatment Recommendations for Cancer Pain: Clinical Guidelines from the Japanese Society of Palliative Medicine

Background: Pain is one of the most common symptoms in cancer patients. The Japanese Society for Palliative Medicine (JSPM) first published its clinical guidelines for the management of cancer pain in 2010. Since then, more research on cancer pain management has been reported, and new drugs have become available in Japan. Thus, the JSPM has now revised the clinical guidelines using a validated methodology. Methods: This guideline was developed through a systematic review, discussion, and the Delphi method, following a formal guideline development process. Results: Thirty-five recommendations were created: 19 for the pharmacological management of cancer pain, 6 for the management of opioid-induced adverse effects, and 10 for pharmacological treatment procedures. Due to the lack of evidence that directly addressed our clinical questions, most of the recommendations had to be based on consensus among committee members and other guidelines. Discussion: It is critical to continue to build high-quality evidence in cancer pain management, and revise these guidelines accordingly.

Comparative study between 2-chloroprocaine and combination of 2-chloroprocaine with fentanyl for spinal anaesthesia

Using fentanyl as an adjuvant in spinal anesthesia has well been documented. Fentanyl being an opioid additive prolongs the duration of neuroaxial blockade without significantly increasing the time to ambulation. Aim: To assess the effect of fentanyl as an adjuvant used with 2-chloroprocaine on sensory and motor onset and offset block time, time for ambulation and complication rate. Methodology: A randomized comparative study was conducted for a period of 6 months in the department of anesthesiology at Kirupananda Variyar medical college and hospital, Salem. A total of 100 patients (50 in each group) posted for elective surgeries in the age group between 20 and 60 were enrolled as our study subjects. Group A patients received intrathecal injection of 3 mL of 1% 2-Chloroprocaine (30 mg) mixed with 0.5 mL of Normal saline and Group B patients received 3 mL of 1% 2-Chloroprocaine (30 mg) mixed with 0.5 mL of Fentanyl solution containing 50 micrograms per mL (25 mcg). Bilateral sensory and motor block onset and regression time was monitored. Results: Time for regression of sensory block, recovery of motor block and time to void urine was comparatively more among group B (2-chloroprocaine with fentanyl) than group A (2-chloroprocaine) and the difference was found to be statistically significant (p < .05). The length of stay in post-anesthesia ICU and the patient satisfaction score did not show a statistical significant difference between the two groups. Similarly no change was noted in hemodynamic parameters and in the incidence of adverse events. Conclusion: We conclude that the addition of fentayl to 2 chloroprocaine has a significant synergistic effect in prolonging postoperative analgesia without prolonging the time for ambulation.

Feasibility of a transmucosal sublingual fentanyl tablet as a procedural pain treatment in colonoscopy patients: a prospective placebo-controlled randomized study

Since patients often experience pain and unpleasantness during a colonoscopy, the present study aimed to evaluate the efficacy and safety of sublingually administered fentanyl tablets for pain treatment. Furthermore, since the use of intravenous drugs significantly increases colonoscopy costs, sublingual tablets could be a cost-effective alternative to intravenous sedation. We conducted a prospective placebo-controlled randomized study of 158 patients to evaluate the analgesic effect of a 100 µg dose of sublingual fentanyl administered before a colonoscopy. Pain, sedation, nausea, and satisfaction were assessed during the colonoscopy by the patients as well as the endoscopists and nurses. Respiratory rate and peripheral arteriolar oxygen saturation were monitored throughout the procedure. There were no differences between the fentanyl and placebo groups in any of the measured variables. The median pain intensity values, as measured using a numerical rating scale, were 4.5 in the fentanyl group and 5 in the placebo group. The sedation and oxygen saturation levels and the respiratory rate did not differ between the groups. The majority of the colonoscopies were completed.Our results indicate that a 100 µg dose of sublingual fentanyl is not beneficial compared to the placebo in the treatment of procedural pain during a colonoscopy.

Effects of age and gender in patients receiving doses of opioids for breakthrough pain proportional to background opioid doses

AIM

To identify the role of age and gender in analgesic and adverse effects after administering fentanyl products for breakthrough pain (BT), given in doses proportional to opioid doses given for background pain.

METHODS

Data from nine studies, in which patients with BP were given fentanyl products in doses proportional to their basal opioid regimen, were analyzed.

RESULTS

A total 462 patients presenting 1905 episodes of BP were included in this analysis. In older patients, the decrease in pain intensity was more pronounced 15 min after administration of a BP medication. No gender differences were found. No significant differences in frequency and intensity of adverse effects for age and gender were found.

CONCLUSION

Fentanyl products given for BP in doses proportional to background opioid regimen were more effective in older patients without adding risks of adverse effects. Gender did not influence analgesia and adverse effects of fentanyl products.

Effect of Opioid Exposure on Efficacy and Tolerability of Sublingual Fentanyl and Subcutaneous Morphine for Severe Cancer Pain Episodes. Secondary Analysis From a Double-Blind Double-Dummy, Randomized Trial

CONTEXT

Few studies have addressed the impact of previous opioid exposure on the effect of opioids for the treatment of severe cancer pain episodes.

OBJECTIVES

We aimed to test whether previous exposure to higher opioid doses was associated with a reduced analgesic effect of fentanyl sublingual tablets (FST) and subcutaneous morphine (SCM) and whether it had an influence on their relative effect.

METHODS

This is a secondary analysis of a placebo-controlled randomized trial comparing 100 μg FST with 5 mg SCM for the acute treatment of severe cancer pain episodes. The effect of previous opioid exposure (oral morphine equivalent daily dose from 20 to 120 mg) on pain intensity difference (PID) and side effects at 30 and 60 minutes after administration (PID 0-30 minutes, PID 0-60 minutes, and adverse events 30-60 minutes) and on re-medication for inefficacy, was studied by multivariable linear and logistic regression models and statistical tests for interaction.

RESULTS

A total of 114 patients were enrolled. Results indicate modest and nonstatistically significant effect of previous opioid exposure on all the outcomes examined (P = 0.11, P = 0.35, P = 0.07, and P = 0.52, respectively, for PID 0-30 minutes, re-medication, PID 0-60 minutes, and adverse events 30-60 minutes). Nonstatistically significant tests for interaction for all models indicated a lack of impact of previous opioid exposure on the difference in the analgesic effect between treatments.

CONCLUSION

In this study, we could not demonstrate an effect of previous opioid exposure, from 20 to 120 mg oral morphine equivalent daily dose, on the absolute and relative efficacy and tolerability of 100 μg FST and 5 mg SCM for severe cancer pain episodes.

Demonstrating Heterogeneity of Treatment Effects Among Patients: An Overlooked but Important Step Toward Precision Medicine

Although heterogeneity in the observed outcomes in clinical trials is often assumed to reflect a true heterogeneous response, it could actually be due to random variability. This retrospective analysis of four randomized, double-blind, placebo-controlled multiperiod (i.e., episode) crossover trials of fentanyl for breakthrough cancer pain illustrates the use of multiperiod crossover trials to examine heterogeneity of treatment response. A mixed-effects model, including fixed effects for treatment and episode and random effects for patient and treatment-by-patient interaction, was used to assess the heterogeneity in patients' responses to treatment during each episode. A significant treatment-by-patient interaction was found for three of four trials (P < 0.05), suggesting heterogeneity of the effect of fentanyl among different patients in each trial. Similar analyses in other therapeutic areas could identify conditions and therapies that should be investigated further for predictors of treatment response in efforts to maximize the efficiency of developing precision medicine strategies.

Breakthrough Cancer Pain: A Systematic Review of Pharmacologic Management

BACKGROUND

Breakthrough cancer pain (BtCP), defined as a transient exacerbation of pain that occurs in conjunction with well-controlled background pain, is a common and burdensome problem in patients with cancer.
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OBJECTIVES

The aim of this systematic review is to identify evidence-based pharmacologic modalities for adequate management of BtCP. 
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METHODS

PubMed and CINAHL® databases were searched to identify literature regarding pharmacologic strategies for BtCP published from January 2006 to June 2016. These studies were then synthesized by the Oncology Nursing Society Putting Evidence Into Practice pain team. 
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FINDINGS

Forty-four studies provide evidence for the use of opioids for the management of BtCP. Transmucosal immediate-release fentanyl (TIRF) was found to have the most evidence for BtCP. Five studies and guidelines also suggest that oral opioids (not including TIRF products) be dosed proportionally to baseline opioids at 10%-20% of the 24-hour, around-the-clock dose.

Nitrous oxide/oxygen mixture for analgesia in adult cancer patients with breakthrough pain: A randomized, double-blind controlled trial

BACKGROUND

The aim of this study was to assess the efficacy of a fixed nitrous oxide/oxygen mixture for the management of breakthrough cancer pain.

METHODS/DESIGN

A double-blind, placebo-controlled, randomized clinical trial was undertaken in the Medical ward of Tumor Hospital of General Hospital of Ningxia Medical University. 240 cancer patients with breakthrough pain were recruited and randomly received a standard pain treatment (morphine sulphate immediate release) plus a pre-prepared nitrous oxide/oxygen mixture, or the standard pain treatment plus oxygen. The primary endpoint measure was the numerical rating scale (NRS) score measured at baseline, 5 and 15 min after the beginning of treatment, and at 5 min post treatment.

RESULT

In all, analysis of pain score (NRS) at 5 min after the beginning of treatment shown a significant decrease in nitrous oxide/oxygen mixture treated patients with 2.8 ± 1.3 versus 5.5 ± 1.2 in controls (p < 0.01). At 15 min during the intervention, the mean pain score for nitrous oxide/oxygen was 2.0 ± 1.1 compared with 5.6 ± 1.3 for oxygen (p < 0.01).

CONCLUSION

This study shows that self-administered nitrous oxide/oxygen mixture was effective in reducing moderate to severe breakthrough pain among patients with cancer.

SIGNIFICANCE

The management of breakthrough cancer pain is always a challenge due to its temporal characteristics of rapid onset, moderate to severe in intensity, short duration (median 30-60 min). Our study find that self-administered nitrous oxide/oxygen mixture was effective in reducing moderate to severe breakthrough cancer pain.

Pharmacokinetics and safety of fentanyl sublingual spray and fentanyl citrate intravenous: a single ascending dose study in opioid-naïve healthy volunteers

OBJECTIVE

Fentanyl sublingual spray offers rapid pain relief in opioid-tolerant cancer patients, and may be useful in acute or post-operative pain. Both opioid-naïve and non-tolerant patients are likely to receive opioids in these settings. Understanding the relationship between systemic exposure of fentanyl sublingual spray and effects on respiratory function in opioid-naïve or non-tolerant populations is important to ensure patient safety. This study evaluated single-dose fentanyl sublingual spray in opioid-naïve participants.

RESEARCH DESIGN

Participants were randomized to receive single-dose fentanyl sublingual spray (100, 200, 400, 600, 800 mcg) or fentanyl citrate IV in one of five cohorts. Dosing occurred following a 10-h fast, with fasting continuing for 4 h post-dose. Dose proportionality was assessed using analysis of variance and linear regression techniques. PK assessments and safety monitoring were performed through 24 h post-dose. Safety assessments, including adverse event (AE) monitoring, occurred from dosing through Day 7.

RESULTS

Fifty participants (19-53 years) received fentanyl sublingual spray or fentanyl citrate IV. Mean maximum plasma concentrations were reached between 0.27-0.60 h post-dose for fentanyl sublingual spray. Peak (C_max) and total (AUC_0-t, AUC_0-∞) fentanyl exposures increased in a linear, but more than dose-proportional manner, with higher doses. The most common AEs were somnolence, nausea, and vomiting. All AEs were mild or moderate in severity. Doses at 400, 600, and 800 mcg were associated with nausea and vomiting, requiring pharmacologic intervention. Hypoxia episodes requiring nasal cannula oxygenation were observed with 600mcg and 800mcg doses.

CONCLUSIONS

Overall, single-dose fentanyl sublingual spray (100-800 mcg) was generally well tolerated, with greater incidences of AEs (e.g. nausea, vomiting, hypoxia) at higher doses. Doses up to 200 mcg may be safely administered to healthy opioid-naïve individuals with routine monitoring; doses between 400-800 mcg may be administered in settings with nasal cannula oxygenation.

Fentanyl sublingual spray for breakthrough cancer pain in patients receiving transdermal fentanyl

AIM

To investigate the relationship between effective fentanyl sublingual spray (FSS) doses for breakthrough cancer pain (BTCP) and around-the-clock (ATC) transdermal fentanyl patch (TFP).

METHODS

Adults tolerating ATC opioids received open-label FSS for 26 days, followed by a 26-day double-blind phase for patients achieving an effective dose (100-1600 µg).

RESULTS

Out of 50 patients on ATC TFP at baseline, 32 (64%) achieved an effective dose. FSS effective dose moderately correlated with mean TFP dose (r = 0.4; p = 0.03). Patient satisfaction increased during the study. Common adverse event included nausea (9%) and peripheral edema (9%).

CONCLUSION

FSS can be safely titrated to an effective dose for BTCP in patients receiving ATC TFP as chronic cancer pain medication. ClinicalTrials.gov identifier: NCT00538850.

Long-term safety of fentanyl sublingual spray in opioid-tolerant patients with breakthrough cancer pain

PURPOSE

The current study assessed the long-term safety of fentanyl sublingual spray for managing breakthrough cancer pain (BTCP).

METHODS

This open-label, multicenter study enrolled both de novo and rollover patients who completed a double-blind, efficacy trial. Eligible patients were ≥18 years of age and experiencing pain that was being managed with an around-the-clock opioid yet were experiencing ≤4 BTCP episodes daily and were opioid-tolerant (i.e., receiving ≥60 mg/day oral morphine or an equivalent dose of another opioid for ≥1 week). De novo patients initially entered a 21-day titration period to identify an effective dose of fentanyl sublingual spray (100-1600 μg), then entered a 90-day maintenance period. The incidence of adverse events (AEs), results of laboratory tests, vital sign assessments, and treatment satisfaction were assessed.

RESULTS

Of the 269 patients (de novo, 179; rollover, 90) who entered the maintenance period, 163 (60.6 %) completed the study; the primary reason for discontinuation was an AE (22.3 %). Eighty percent of patients identified an effective dose of fentanyl sublingual spray (median dose, 600 μg). The most common AEs differed from the titration period (nausea (13 %), vomiting (12 %), and somnolence (10 %)) to the maintenance period (malignant neoplasm progression (24 %), vomiting (16 %), and peripheral edema (12 %)). Few changes in laboratory parameters and vital sign assessments were observed. Patients generally reported being more satisfied with fentanyl sublingual spray than with their previous BTCP treatment.

CONCLUSIONS

This long-term maintenance study demonstrated that fentanyl sublingual spray was generally safe and well tolerated for managing BTCP over a 90-day period.

Effective Dose Titration of Fentanyl Sublingual Spray in Patients With Breakthrough Cancer Pain

OBJECTIVE

To further describe effective dose titration of fentanyl sublingual spray to treat breakthrough cancer pain (BTCP) during the 26-day open-label titration phase of a phase 3, randomized, double-blind, placebo-controlled study.

METHODS

Opioid-tolerant patients with 1 to 4 episodes of BTCP per day were enrolled. For randomization into double-blind treatment, patients must have titrated to a dose (100 to 1,600 mcg) providing effective analgesia for 2 consecutive BTCP episodes. The Treatment Satisfaction Questionnaire for Medication was administered at baseline and at titration end and included a Global Satisfaction domain.

RESULTS

Of 130 patients undergoing titration, 98 (75%) achieved pain relief (median dose = 800 mcg). The most common doses that allowed for adequate pain relief were 800 mcg (24.5%) and 1,200 mcg (20.4%). Of 32 (25%) patients who withdrew from the study, only 3 (2.3%) did not achieve an effective dose. In patients attaining an effective dose, mean Global Satisfaction increased from 54.9 ± 2.1 at baseline to 75.3 ± 1.7 at the end of the titration phase. Seventy-eight patients (60%) reported ≥ 1 adverse event (AE). Thirty-three AEs (25.4%) were considered probably related to treatment, with nausea (6.2%) and somnolence (4.6%) most commonly reported.

CONCLUSIONS

In patients with BTCP, fentanyl sublingual spray can be rapidly and safely titrated to an effective dose, resulting in greater satisfaction with fentanyl sublingual spray than previous BTCP medications.

Transmucosal Immediate-Release Fentanyl for Breakthrough Cancer Pain: Opportunities and Challenges for Use in Palliative Care

Opioids are used to treat breakthrough cancer pain (BTCP) and can be classified by relative duration and onset of action. Regulatory approvals of numerous transmucosal immediate-release fentanyl (TIRF) formulations provide alternative options to palliative care-trained providers in the management of BTCP. TIRFs have been formulated as a sublingual tablet, sublingual spray, intranasal spray, pectin-based nasal spray, buccal tablet, and buccal soluble film. Differences exist between TIRFs regarding formulation design and dosing to treat BTCP. Opportunities for use include palliation of BTCP in head and neck cancer and/or radiation-induced mucositis. The purpose of this review is to discuss TIRF formulation and dosing, pharmacokinetics, clinical efficacy, patient acceptability, and safety/tolerability. In addition, barriers to TIRF utilization will be discussed.

WITHDRAWN: Opioids for the management of breakthrough pain in cancer patients

At August 2015, this review has been withdrawn. It is correct at the date of publication, and previous versions can be accessed in the ‘Other versions’ tab on the Cochrane Library. The Cochrane Editorial Unit (CEU) agreed with the authors of the feedback that the review was misleading, and because the original author team was unavailable to update the review, the CEU advised that it should be withdrawn. See below for full details. PaPaS is seeking a new author team to develop a new review which will serve to update the original.

Feedback 1, received 15 February 2015

Dr Vicente Ruiz Garcia
 vicenteruizgarcia@gmail.com

With colleagues Xavier Bonfill Cosp, Eduardo Lopez Briz, Rafa Carbonell, Jose Luis Gonzalvez Perales, Sylvia Bort Martí, and Marta Roque Figuls.

Comment: Dear editor:

We have read the update of Zeppetella and Davies about management of breakthrough pain in cancer patients (1). We think that this review is very important to help clinicians and patients to decide whether the new treatments for the breakthrough pain in cancer could be a useful alternative to morphine.

In this update, some comments that we made to the previous review (the letter was not published) (2) were considered by the authors; in particular, not pooling the results obtained for oral transmucosal fentanyl citrate (OTFC) versus placebo, with those of OTFC versus morphine, and those of two trials that were titration of doses of fentanyl. However, we do not agree with the authors’ results when they state: “When compared with placebo or oral morphine, participants gave lower pain intensity and higher pain relief scores for transmucosal fentanyl formulations at all time points”. First, the outcomes at 15 min (the most important to obtain a quick relief of pain), Pain intensity Difference (Comparison 2. Transmucosal opioid versus oral morphine) and Comparison 4. OTFC versus intravenous morphine), failed to show statistically significant differences with oral morphine (mean difference 0.37 CI 95% 0.00‐0.73) and with morphine iv (mean difference 0.80 CI 95% 0.00‐1,60). In any case the results had no clinical relevance. Moreover the authors state “at all time points”, whereas they do not provide any data for longer times (i.e. 30, 45, 60 min). In addition, authors state “transmucosal fentanyl citrate are safe (..) (compared with both placebo and morphine) in relieving breakthrough pain”. Surprisingly no analysis of adverse events have been done that were only described in each study. Seven out 15 were crossover trials and it was impossible to draw conclusions about it.

As reviewers we know that multiple comparisons could be made, but the most clinical interesting comparison is the gold standard, morphine.

The review only shows in SOF, comparisons of fentanyl with placebo and concludes, that it is effective. Surprisingly, there is no mention of morphine comparison, which we consider a key point, because no patient will take placebo if he has a breakthrough pain, but morphine for obvious reasons.

In our opinion, traversing the authors’ conclusions, this review did not show that the use of oral and nasal transmucosal fentanyl is an effective alternative to morphine for patients with breakthrough cancer pain.

Reply

The authors of the review were contacted but chose not to provide a response to the feedback.

Contributors

Kate Seers, PaPaS Feedback Editor, and Anna Hobson, PaPaS Managing Editor.

Additional feedback 2, received May 2015

On 15 February 2015, Dr Vicente Ruiz Garcia (University Hospital La Fe, Spain), and his colleagues Xavier Bonfill Cosp, Eduardo Lopez Briz, Rafa Carbonell, Jose Luis Gonzalvez Perales, Sylvia Bort Martí, and Marta Roque Figuls submitted feedback via the Cochrane Library. The main complaint is available above.

On 23 February, 16 March and 15 April, Kate Seers (Feedback Editor, PaPaS) contacted the authors and invited them to respond. On 21 March, John Zeppetella (lead author) declined to provide a formal response. No response was received from Andrew Davies (second author).

On 31 March, PaPaS sought advice from the Cochrane Editorial Unit (CEU) on how to manage the issue; advised to publish without a response, depending on nature of feedback.

On 11 May 2015, review re‐published with feedback incorporated.

On 20 May 2015, Marta Roqué Figuls (Statistician, Iberoamerican Cochrane Centre) wrote to the CEU repeating the initial claim. They did not agree with the approach decided upon by the Co‐Ed, which was supported by the EiC. They stated “The CCIb assessment is that the review presents methodological shortcomings, and the conclusions are skewed in favor of fentanyl. Consequently, we support Vicente and colleagues’ petition to re‐assess the publication status of the review.”

Reply

On 9 June, Christopher Eccleston (Co‐ordinating Editor, PaPaS) advised that the review remain unchanged until it was ready for updating in September 2015.

On 25 June 2015 David Tovey (Editor in Chief, Cochrane) responded to say “We have now had a chance to appraise this review and also obtain a report from our screening team… In summary we agree with almost all of the criticisms made of the review, and are concerned that the flaws may mean that the findings are misleading as currently presented. We note that the authors have declined to respond to the useful comments provided by Vicente. Having considered this and discussed it internally, we agree with our colleagues at the IbCC that the review should be withdrawn temporarily until the errors have been fixed and the review updated. We would like to re‐screen the review before any update or amendment is published.”

On 2 July and 23 July, Anna Hobson (Managing Editor, PaPaS) again invited the authors to respond to the initial feedback and subsequent reviews by 23 July. No response was forthcoming.

At August 2015, the review was withdrawn.

Contributors

Kate Seers (Feedback Editor, PaPaS), Cochrane Editorial Unit (CEU), Christopher Eccleston (Co‐ordinating Editor, PaPaS), David Tovey (Editor in Chief, Cochrane), Anna Hobson (Managing Editor, PaPaS).

The editorial group responsible for this previously published document have withdrawn it from publication.

The fentanyl story

Fentanyl, introduced more than 50 years ago, has become the most often used opioid for intraoperative analgesia. Since the early 1990s the fentanyl patch has been available for management of chronic pain of all forms of cancer as well as the persistent, intense pain from many noncancerous maladies. More than a half dozen rapid-onset transmucosal fentanyl preparations have been developed, approved, launched, and popularized for "breakthrough" pain syndromes in the past 20 years. The purpose of this article is to describe why this opioid has become so important in the treatment of pain in modern clinical practice. The data indicate that fentanyl's popularity has occurred because it has minimal cardiovascular effects, does not result in increases in plasma histamine, is relatively short in onset of action and duration of effect, is easy and inexpensive to synthesize and prepare for the marketplace, and is now familiar to clinicians working in pain and perioperative medicine throughout the world.

Efficacy and tolerability of intranasal fentanyl spray in cancer patients with breakthrough pain

PURPOSE

The aims of this study were to explore the efficacy of intranasal fentanyl spray* (INFS) 400 μg to evaluate 12-week tolerability of the nasal mucosa and to explore safety data for all dose strengths of INFS in patients with cancer-related breakthrough pain (BTP).

METHODS

Patients received a test dose of INFS 50 μg, followed by a titration phase. Those patients with doses titrated to 200 or 400 μg entered a randomized, double-blind, cross-over efficacy phase, in which 8 episodes of BTP were randomly treated with INFS 400 μg (6 episodes) and placebo (2 episodes), followed by a tolerability phase. Patients with doses titrated to 50 or 100 μg entered the tolerability phase directly. Primary outcome was measured by pain intensity difference at 10 minutes, analyzed using ANCOVA, and presented as least square mean difference. Examination of the nasal cavity was conducted at inclusion and after 12 weeks of treatment by an otorhinolaryngologist.

FINDINGS

Forty-six patients were included. Thirty-eight patients' doses were titrated to an effective dose of INFS; 50 μg (n = 8), 100 μg (n = 9), 200 μg (n = 9), and 400 μg (n = 12); 15 patients entered the efficacy phase and 31 entered the tolerability phase. In the efficacy phase, 88 and 29 episodes of BTP were treated with INFS 400 μg and placebo, respectively. Pain intensity difference at 10 minutes least square mean for INFS 400 μg was 2.5 (95% CI, 1.42-3.49) (P < 0.001) and least square mean difference between INFS 400 μg and placebo was 1.1 (95% CI, 0.41-1.79) (P = 0.002). Runny nose (10%) and change in color of the mucosa (9%) were the most frequent findings of nasal examination, and nausea and dizziness were the most frequent treatment-related adverse events. One serious adverse event (ie, respiratory depression) was considered related to INFS.

IMPLICATIONS

INFS 400 μg is effective and nasal tolerability and overall safety profile is acceptable during 12 weeks of use. ClinicalTrials.gov identifier: NCT01429051.

Rapid-onset opioids for the treatment of breakthrough cancer pain: two cases of drug abuse

SETTING

In the last few years, the use of opioids for cancer pain has rapidly increased and new molecules have been developed. Currently, rapid-onset opioids are widely used in clinical practice for breakthrough cancer pain (BTcP). However, the tolerability of these molecules is still a matter of debate.

PATIENTS

We describe two cases of rapid-onset opioids misuse that have been recently observed at our palliative care unit.

DISCUSSION

The reported cases are explicative as they occurred in patients suffering from different types of cancer and with different causes of BTcP. Further investigations are needed to identify factors predicting addiction to this new class of molecules.

Interventional modalities to treat cancer-related pain

Cancer-related pain is a significant cause of morbidity in those affected by both primary and metastatic disease. Although oral, transdermal, and parenteral opioid medications are an integral part of the World Health Organization's analgesic ladder, their use may be limited by side effects. Fortunately, there are advanced interventional pain management strategies effective in reducing pain in the cancer patient while mitigating the aforementioned side effects. Celiac plexus blocks and neurolysis have been proven effective in treating cancers of the abdominal viscera (ie, pancreas). Transversus abdominis plane blocks, neurolysis, and catheter placement can be used to treat cancer pain associated with the abdominal wall. Peripheral nerve blocks and catheter placement at the brachial and lumbosacral plexus or peripheral nerves treat cancer pain associated with the upper and lower limbs, whereas paravertebral and intercostal blocks treat cancer pain associated with the chest wall and ribs. Finally, alternate drug delivery methods such as intrathecal drug delivery systems concentrate medication at central opioid receptors without affecting the peripheral receptors implicated in unwanted side effects. This article provides an overview of these interventions, including indications, contraindications, and potential complications of advanced interventional pain management options available for the treatment of intractable cancer-related pain.

Patient Satisfaction with Fentanyl Sublingual Spray in Opioid-Tolerant Patients with Breakthrough Cancer Pain

OBJECTIVES

Breakthrough cancer pain (BTCP) is associated with decreased satisfaction with around-the-clock opioid therapy. This analysis examined patient satisfaction with fentanyl sublingual spray for BTCP during the open-label titration period of a randomized, placebo-controlled study.

METHODS

Opioid-tolerant patients with 1 to 4 daily BTCP episodes were included. During a 26-day, open-label titration phase, a successful dose (100 to 1600 mcg) of fentanyl sublingual spray was established that provided effective analgesia for 2 consecutive BTCP episodes with tolerable side effects. The Treatment Satisfaction Questionnaire for Medication (TSQM) was administered at baseline to assess satisfaction with previous BTCP medication and at the end of the titration to assess satisfaction with fentanyl sublingual spray.

RESULTS

Of 130 enrolled patients, 115 (88.5%) had a TSQM measure at baseline and at the end of their titration period. Scores on all 4 TSQM domains increased from baseline to end of the titration, with mean (standard error [SE]) improvements of 22.3 (2.3) for effectiveness, 7.7 (3.2) for side effects, 6.8 (2.2) for convenience, and 12.9 (2.8) for global satisfaction (P < 0.05 for all). Satisfaction with symptom relief (26.1% to 77.4%) and onset of action (21.7% to 82.6%) also improved from baseline to end of titration. At least one adverse event (AE) was reported by 78 patients (60.0%). The most common AEs considered possibly or probably related to study medication were dizziness, somnolence, and nausea (n = 10 [7.7%] each).

DISCUSSION

These data indicate markedly improved satisfaction among patients receiving fentanyl sublingual spray relative to previous BTCP medications.

Breakthrough cancer pain (BTcP): a synthesis of taxonomy, pathogenesis, therapy, and good clinical practice in adult patients in Italy

Pain presents in 80% of patients with advanced cancer, and 30% have periods of increased pain due to fluctuating intensity, known as breakthrough cancer pain (BTcP). BTcP is high-intensity, short-duration pain occurring in several episodes per day and is non-responsive to treatment. The clinical approach to BTcP is variable. A review of the literature was performed to provide clinicians and practitioners with a rational synthesis of the ongoing scientific debate on BTcP and to provide a basis for optimal clinical approach to BTcP in adult Italian patients. Data show that circadian exacerbations of pain should be carefully monitored, differentiating, if possible, between fluctuations of background pain (BP), end-of-dose effect, and BTcP. BTcP should be monitored in all care contexts in clinical practice and each care facility must have all the medications and products approved for use in BTcP at their disposal. Data show that knowledge about medications for BTcP is lacking: medications for BTcP treatment are not interchangeable, although containing the same active substance; each physician must know the specific characteristics of each medication, its pharmacological properties, limitations in clinical practice, specifics relating to titration and repeatability of administration, and technical specifics relating to the accessibility and delivery. Importantly, before choosing a rapid-onset opioid (ROO), it is essential to deeply understand the status of patient and the characteristics of their family unit/caregivers, taking into account the patient’s progressive loss of autonomy and/or cognitive-relational functionality. When BTcP therapy is initiated or changed, special attention must be paid to training the patient and family members/caregivers, providing clear instructions regarding the timing of drug administration. The patient must already be treated effectively with opioids before introducing ROOs for control of BTcP.

Assessing age and gender in studies of breakthrough pain medications

OBJECTIVE

The present review was performed to identify possible differences observed between adults and elderly patients and between males and females in randomized clinical trials of breakthrough pain (BTP).

METHODS

A systematic search of the existing literature from 1998 to September 2013 was performed. Randomized clinical trials reporting data on older patients were selected.

RESULTS

Sixteen comparative studies were selected. The age range of inclusion criteria patients was mainly between 18-80 or ≥18 years. In some cases this data was unreported. The mean age of patients was 48-64 years, but information regarding the number of elderly patients was present in three studies only. Gender distribution was more or less 50%:50%. No subgroup analysis of efficacy or adverse effects of BTP medications for age and gender was reported.

CONCLUSION

There is a need for more information regarding the use of opioids for BTP according to age and gender.

New opioids

Despite the skilled use of opioid analgesics, which is crucial to the relief of cancer pain, there is a lack of evidence to support many aspects of current clinical practice. Therefore, there is a significant need for more effective treatment options. New opioids have been marketed in the past years, including hydrocodone and oxymorphone. Moreover, mixed opioids with combined mechanisms of action have been developed; one such agent, tapentadol, is a centrally acting oral analgesic that possesses a combined mechanism of action: μ-opioid receptor activation with norepinephrine reuptake inhibition. Drug development strategies involving naloxone have been initiated to reduce peripheral opioid-related adverse effects. The rationale is based on the local antagonist activity of naloxone in intestinal opioid receptors and the negligible oral bioavailability of naloxone, particularly in a prolonged-release formulation. New delivery systems have been developed to provide rapid analgesia with potent opioid drugs such as fentanyl. Despite the upcoming availability of these new drugs and technologies that will add to existing types of opioid medication, their benefits and liabilities will ultimately need to be determined by the individual physician and individual patient experiencing pain.

Pharmacokinetics and dose proportionality of fentanyl sublingual spray: a single-dose 5-way crossover study

BACKGROUND

Fentanyl sublingual spray is a novel formulation of fentanyl for sublingual delivery that was designed to enhance the rate and extent of absorption of fentanyl for management of breakthrough cancer pain (BTCP).

OBJECTIVES

The primary objective of this study was to determine the pharmacokinetics and dose proportionality of 5 different doses (100, 200, 400, 600, and 800 μg) of fentanyl sublingual spray in healthy subjects under fasted conditions (part A); the secondary objective was to assess the effects of temperature and pH in the oral cavity on relative bioavailability of fentanyl (part B).

METHODS

Analyses were performed on venous blood samples drawn 5 min to 36 h after administration of fentanyl sublingual spray (Subsys(®), Insys Therapeutics, Inc., Chandler, AZ, USA). Part A of this phase I study was a 5-treatment, 5-sequence, 5-period crossover study in which subjects received a single treatment of each of the 5 fentanyl sublingual spray doses. Dose proportionality was assessed using analysis of variance and linear regression techniques. Part B was a 5-treatment, 2-sequence, 5-period crossover study in which subjects received a single assigned dose of fentanyl sublingual spray 200 μg under the following 5 conditions: no pretreatment, pretreatment with cold or hot beverage, and pretreatment with low- or high-pH beverage. Naltrexone was administered to block potential opioid effects associated with fentanyl. Adverse events (AEs) were monitored and recorded throughout the study.

RESULTS

Fifty-three subjects (15 men, 38 women; mean age, 31 years) were enrolled in part A. Fourteen subjects (11 men, 3 women; mean age, 32 years) were enrolled in part B. The first quantifiable mean plasma concentrations of fentanyl were observed at the first sample time (5 min) for all doses. Mean maximum plasma concentration (C(max)) increased with increases in dose, whereas median time to reach C max (t max) tended to decrease with increases in dose. The dose-normalized C(max), area under the plasma concentration-time curve from time zero to infinity (AUC∞), and AUC from time zero to time of last measurable concentration (AUClast) values were linear and consistent with dose proportionality across the 100-800 μg dose range. Pretreatment of the oral cavity with a cold or hot beverage, or low- or high-pH beverage, did not appreciably alter fentanyl absorption (C(max) and AUC∞ values). The most commonly reported AEs were nausea and vomiting.

CONCLUSIONS

In healthy subjects, administration of fentanyl sublingual spray produced a rapid rise in fentanyl plasma concentrations. Dose-dependent parameters (C max and AUC) showed dose proportionality across the range of 100-800 μg. Altering the local environment of the oral cavity (temperature and pH) showed no effects on the bioavailability of fentanyl. The rapid and predictable rise in plasma fentanyl concentrations following administration of fentanyl sublingual spray corresponds with the rapid onset and duration of many BTCP episodes.

Opioids for the management of breakthrough pain in cancer patients

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (Issue 1, 2006). Breakthrough pain is a transient exacerbation of pain that occurs either spontaneously or in relation to a specific predictable or unpredictable trigger despite relative stable and adequately controlled background pain. Breakthrough pain usually related to background pain and is typically of rapid onset, severe in intensity and generally self limiting with a mean duration of 30 minutes. Breakthrough pain has traditionally been managed by the administration of supplemental oral analgesia (rescue medication) at a dose proportional to the total around-the-clock (ATC) opioid dose.

OBJECTIVES

To determine the efficacy of opioid analgesics given by any route, used for the management of breakthrough pain in patients with cancer, and to identify and quantify, if data permitted, any adverse effects of this treatment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and trial registries in January 2005 for the original review, and again on 6 February 2013 for this update.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of opioids used as rescue medication against active or placebo comparator in patients with cancer pain. Outcome measures sought were reduction in pain intensity measured by an appropriate scale, adverse effects, attrition, patient satisfaction and quality of life. We applied no language restrictions.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected and examined eligible studies. We retrieved full text if any uncertainty about eligibility remained. We screened non-English texts. We conducted quality assessment and data extraction using standardised data forms. We compared drug and placebo dose, titration, route and formulation and recorded details of all outcome measures (if available).

MAIN RESULTS

The original review included four studies (393 participants), all concerned with the use of oral transmucosal fentanyl citrate (OTFC) in the management of breakthrough pain. Two studies examined the titration of OTFC, one study compared OTFC versus normal-release morphine and one study compared OTFC versus placebo.Fifteen studies (1699 participants) met the inclusion criteria for this update. All studies reported on the utility of seven different transmucosal fentanyl formulations, five of which were administered orally and two nasally. Eight studies compared the transmucosal fentanyl formulations versus placebo, four studies compared them with another opioid, one study was a comparison of different doses of the same formulation and two were randomised titration studies. Oral and nasal transmucosal fentanyl formulations were an effective treatment for breakthrough pain. When compared with placebo or oral morphine, participants gave lower pain intensity and higher pain relief scores for transmucosal fentanyl formulations at all time points. Global assessment scores also favoured transmucosal fentanyl preparations. One study compared intravenous with the transmucosal route and both were effective.

AUTHORS' CONCLUSIONS

Oral and nasal transmucosal fentanyl is an effective treatment in the management of breakthrough pain. The RCT literature for the management of breakthrough pain is relatively small. Given the importance of this subject, more trials, including head-to-head comparisons of the available transmucosal fentanyl formulations are required.

Single-dose pharmacokinetics of fentanyl sublingual spray and oral transmucosal fentanyl citrate in healthy volunteers: a randomized crossover study

BACKGROUND

Fentanyl sublingual spray (FSS) is a novel fentanyl formulation recently developed for the treatment of breakthrough cancer pain, which is characterized by a fast onset and a relatively short duration.

OBJECTIVE

To compare rate of absorption and systemic bioavailability between FSS and oral transmucosal fentanyl citrate (OTFC) in healthy volunteers.

METHODS

This randomized 3-way crossover study involved 29 healthy volunteers (25 men and 4 women; mean age, 35 years) who received single doses of FSS (400 μg), OTFC (400 μg), and intravenous fentanyl citrate (100 μg) separated by washout periods of ≥7 days. Oral naltrexone was given to minimize potential adverse effects of fentanyl. Plasma fentanyl concentrations were measured for 36 hours after each dose for the calculation of pharmacokinetic parameters.

RESULTS

Mean Cmax values of fentanyl were higher with FSS versus OTFC (0.81 ng/mL vs 0.61 ng/mL) and were attained more quickly; the median Tmax was 1.5 hours with FSS and 2.0 hours with OTFC (P < 0.05). Furthermore, potentially effective fentanyl concentrations were achieved more quickly with FSS than with OTFC. Five and 10 minutes after administration, mean plasma concentrations were 19.0% and 53.7% of Cmax with FSS, respectively, compared with levels below the lower limit of assay quantification and 6.1%, respectively, with OTFC. Plasma concentrations of fentanyl at 10 minutes with FSS were equivalent to those with OTFC at 60 minutes. The Cmax and AUCs were approximately 33% to 36% greater with FSS than with OTFC, and the 90% CIs of the geometric mean ratios for each parameter fell outside the bioequivalence range of 80% to 125%. Systemic bioavailability was also greater with FSS than with OTFC (approximately 76% vs 51%). All 3 fentanyl treatments were well tolerated. All reported adverse events were mild and consistent with those previously reported in healthy volunteers receiving transmucosal fentanyl with naltrexone, and none occurred in >2 participants during any treatment period.

CONCLUSIONS

Absorption of fentanyl in this study was faster and bioavailability was greater with FSS than with OTFC. The pharmacokinetic profile of the sublingual spray closely matches the duration of onset to pain intensity in a breakthrough cancer pain episode. These findings suggest that FSS is appropriate for the treatment of breakthrough cancer pain. ClinicalTrials.gov identifier: NCT01780233.

Single-dose fentanyl sublingual spray for breakthrough cancer pain

Breakthrough cancer pain (BTCP) is defined as a transient exacerbation of pain that arises in patients with otherwise controlled persistent pain. BTCP typically has a rapid onset and relatively short duration, but it causes a significant amount of physical and psychological distress for patients. Several rapid-onset fentanyl formulations have been introduced in the USA to replace traditional oral opioids for the treatment of BTCP: a transmucosal lozenge, a sublingual orally disintegrating tablet, a buccal tablet, a buccal soluble film, a pectin nasal spray and, the newest formulation to enter the market, a sublingual spray. This article reviews the six rapid-onset formulations of fentanyl approved in the USA for the management of BTCP with emphasis on describing the published literature on fentanyl sublingual spray. The different fentanyl formulations vary in pharmacokinetic properties and ease of use, but all have a rapid onset and a relatively short duration of analgesia. Fentanyl sublingual spray has demonstrated absorption within 5 minutes of administration, with fentanyl plasma concentrations increasing over the first 30 minutes and remaining elevated for 60–90 minutes in pharmacokinetic studies in healthy subjects. Fentanyl sublingual spray shows linear dose proportionality, and changes in the temperature or acidity of the oral cavity do not alter its pharmacokinetic properties. In patients with BTCP, statistically significant pain relief is measurable at 5 minutes after administration of fentanyl sublingual spray, when compared with placebo, with significant pain relief lasting at least 60 minutes after administration. Adverse events are typical of opioid treatment and are considered mild to moderate in intensity. In summary, fentanyl sublingual spray provides rapid onset of analgesia and is a tolerable and effective treatment for BTCP.

Pharmacokinetics of non-intravenous formulations of fentanyl

Fentanyl was structurally designed by Paul Janssen in the early 1960s as a potent opioid analgesic (100-fold more potent than morphine). It is a full agonist at μ-opioid receptors and possesses physicochemical properties, in particular a high lipophilicity (octanol:water partition coefficient >700), which allow it to cross quickly between plasma and central nervous target sites (transfer half-life of 4.7-6.6 min). It undergoes first-pass metabolism via cytochrome P450 3A (bioavailability ~30 % after rapid swallowing), which can be circumvented by non-intravenous formulations (bioavailability 50-90 % for oral transmucosal or intranasal formulations). Non-intravenous preparations deliver fentanyl orally-transmucosally, intranasally or transdermally. Passive transdermal patches release fentanyl at a constant zero-order rate for 2-3 days, making them suitable for chronic pain management, as are iontophoretic transdermal systems. Oral transmucosal and intranasal routes provide fast delivery (time to reach maximum fentanyl plasma concentrations 20 min [range 20-180 min] and 12 min [range 12-21 min], respectively) suitable for rapid onset of analgesia in acute pain conditions with time to onset of analgesia of 5 or 2 min, respectively. Intranasal formulations partly bypass the blood-brain barrier and deliver a fraction of the dose directly to relevant brain target sites, providing ultra-fast analgesia for breakthrough pain. Thanks to the development of non-intravenous pharmaceutical formulations, fentanyl has become one of the most successful opioid analgesics, and can be regarded as an example of a successful reformulation strategy of an existing drug based on pharmacokinetic research and pharmaceutical technology. This development broadened the indications for fentanyl beyond the initial restriction to intra- or perioperative clinical uses. The clinical utility of fentanyl could be expanded further by more comprehensive mathematical characterizations of its parametric pharmacokinetic input functions as a basis for the rational selection of fentanyl formulations for individualized pain therapy.

Considerations in selecting rapid-onset opioids for the management of breakthrough pain

Breakthrough pain (BTP) is a transitory pain that occurs despite the use of long-term, around-the-clock analgesia. It is highly prevalent in certain populations and places a significant burden on patients, their families, caregivers, and health-care systems. Despite its prevalence and impact, BTP is sometimes unrecognized and often undertreated. Various formulations of fentanyl – a rapid-onset opioid with short duration of action – are available for the management of BTP. The efficacy of formulations using transmucosal, transbuccal, sublingual, and intranasal administration routes has been demonstrated for BTP treatment in clinical trials. However, a lack of head-to-head trials evaluating their relative efficacy makes it challenging for physicians to reach informed decisions on the most efficacious intervention for individual patients. In the absence of clear data on the relative efficacy of fentanyl formulations, prescribing decisions need to be based on physician understanding and experience and product cost and availability, taking into account the individual patient’s needs, the ability of the patient or caregivers to administer medication, and the patient’s wishes. This review evaluates current pharmacologic methods of alleviating BTP and discusses factors that should be considered when selecting the most appropriate formulation for individual patients. With the range of fentanyl formulations available, it is now possible to successfully address BTP in the majority of patients.

Fentanyl sublingual spray for breakthrough pain in cancer patients

Breakthrough pain is a transient exacerbation of pain that occurs either spontaneously, or in relation to a specific predictable or unpredictable trigger, despite relatively stable and adequately controlled background pain. Typically, breakthrough pain has a fast onset and short duration, and a significant impact on patients’ quality of life. Normal-release oral opioids are the traditional pharmacological approach for patients who are receiving an around the clock opioid regimen; however, their onset and duration of action may not be suitable for treating many breakthrough pains. Efforts to provide nonparenteral opioid formulations that could provide more rapid, and more effective, relief of breakthrough pain have led to the development of transmucosal opioid formulations including fentanyl sublingual spray (FSLS). This is a formulation of fentanyl available in doses of 100, 200, 400, 600, and 800 μg strengths approved for the management of breakthrough pain in adult cancer patients already receiving and who are tolerant to opioid therapy for their underlying persistent cancer pain. Published pharmacokinetic, efficacy, tolerability, and safety data suggest that FSLS has a valuable role to play in the symptomatic pharmacological management of breakthrough pain. The effective dose of FSLS is determined by titration according to the needs of the individual patient.

A review of the pharmacokinetic profile of transmucosal fentanyl formulations

BACKGROUND AND OBJECTIVES

Breakthrough pain (BTP) is a transitory flare of moderate-to-severe pain that occurs in patients with stable, controlled persistent pain. Management of BTP episodes is difficult because frequency, time-to-peak intensity, and duration of episodes vary both within and between individuals. Formulations of fentanyl that use a buccal, sublingual, or nasal transmucosal route of administration have been developed for the treatment of BTP in opioid-tolerant patients with cancer. These formulations allow rapid passage into the bloodstream and avoid first-pass metabolism and, therefore, are more likely to match the time-course of BTP episodes than are oral formulations. The purposes of this analysis were to identify and review published data describing the pharmacokinetic properties of rapid-onset fentanyl formulations and to evaluate these properties in view of the temporal dynamic characteristics of BTP in order to help guide medical practice.

METHODS

Relevant publications were searched in the PubMed database from 1998. The plasma drug concentration-time profile of each formulation obtained from the identified studies was adjusted to a consistent scale for comparison.

RESULTS

The data revealed that the various transmucosal formulations resulted in three typical plasma fentanyl concentration profiles: (1) type 1: a very rapid rise and short duration; (2) type 2: a rapid increase and sustained intensity; and (3) type 3: a slower onset and longer duration.

CONCLUSIONS

Given the substantial variability of BTP episodes experienced by patients, these pharmacokinetic differences may provide useful information for a physician who is selecting a rapid-onset opioid medication for a patient.