Multiple dose pharmacokinetics of oral transmucosal fentanyl citrate in healthy volunteers

Severe and Fatal Fentanyl Poisonings from Transdermal Systems after On-Skin and Ingestion Application

In recent years, the administration of fentanyl (FNTL) implicitly in transdermal drug delivery systems (TDDS) has vastly increased in chronic pain treatment. Non-medical and uncontrolled use of FNTL in TFDS (transdermal fentanyl delivery systems) may reveal toxic effects by the route of exposure, dermal or alternative, by ingestion of patches, and drug release in the stomach. The purpose of this study was to present three different cases of FNTL poisonings, two of which resulted in death due to TFDS abuse. The first case is a 66-year-old woman treated for accidental FTNL poisoning resulting in acute respiratory distress syndrome. Two remaining cases are a 31-year-old woman and a 25-year-old man who died as a result of FNTL overdose after on-skin and ingestion application of the drug patches. During the hospitalization of the 66-year-old patient, in blood samples, FNTL was confirmed at a concentration of 10.0 ng/mL. Tests run on blood taken from the corpses of 25- and 31-year-old patients exhibited FNTL presence in concentrations of 29.1 ng/mL and 38.7 ng/mL, respectively. The various routes of administration and ultimately toxic effects are important to present because, in TDDS, fentanyl can be a reason for severe to fatal poisoning, as shown by the three cases above.

Health effects from unintentional occupational exposure to opioids among law enforcement officers: Two case investigations

Recent increases in the rate of drug overdose-related deaths, the emergence of potent opioids such as carfentanil, and media reports of incidents have raised concerns about the potential for work-related exposure to a variety of illicit drugs among law enforcement officers (LEOs), other emergency responders, and other workers in the United States. To characterize the risk associated with unintentional occupational exposure to drugs, we retrospectively investigated two incidents that occurred in 2017 and 2018 where LEOs were exposed to opioid and stimulant drugs and experienced health effects. We interviewed five affected LEOs and others. We reviewed records, including emergency department documentation, incident reports, forensic laboratory results, and when available, body camera footage. Multiple drug types, including opioids and nonopioids, were present at each incident. Potential routes of exposure varied among LEOs and were difficult to characterize with certainty. Health effects were not consistent with severe, life-threatening opioid toxicity, but temporarily precluded affected LEOs from performing their essential job duties. While health risks from occupational exposure to drugs during law enforcement activities cannot currently be fully characterized with certainty, steps to prevent such exposures should be implemented now. The creation and implementation of appropriate controls plus education and training are both important to protecting first responders from these hazardous agents. To more fully characterize potential exposures, timely prospective toxicological evaluation of affected responders is recommended.

Serotonin Syndrome in a Patient on Trazodone and Duloxetine Who Received Fentanyl following a Percutaneous Liver Biopsy

Serotonin syndrome is a rare but potentially life-threatening adverse drug reaction resulting from the use or overuse of serotonergic medications alone or in combination. Mild symptoms, overlapping features with similar conditions and clinician lack of awareness are the major reasons for an often missed diagnosis. Not surprisingly, this condition is significantly underreported as a potential complication of endoscopy if serotonergic medications are used periprocedurally for sedation and analgesia. Here we report the case of a patient with relapsed chronic hepatitis C on antidepressant medications who developed signs and symptoms of serotonin syndrome after a percutaneous liver biopsy. Review of the patient's medication list suggested a possible interaction between her home antidepressants and the post-procedure use of fentanyl for abdominal pain. The patient required monitoring in the medical intensive care unit and stabilized after the administration of benzodiazepines and temporary discontinuation of her home medications. We propose that clinicians need to be aware of the increased risk of serotonin syndrome in the outpatient endoscopy setting, particularly with the wider use of serotonergic antidepressants now available and the repeated number of liver biopsies being performed for management of patients with chronic liver disease.

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.

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.

A comprehensive review of rapid-onset opioids for breakthrough pain

Breakthrough pain (BTP) is a transitory pain (reaching maximum severity in ~15 minutes and lasting ~60 minutes in patients with cancer) that occurs despite the management of chronic pain with long-term around-the-clock analgesia. BTP occurs in 33-65% of patients with chronic cancer pain and in ~70% of patients with chronic noncancer pain. BTP has historically been managed with short-acting opioids; however, these medications have a pharmacokinetic profile that does not correlate with the sudden onset and short time to maximum severity of BTP. Interest in rapid-onset opioids to relieve BTP has therefore been growing. This comprehensive review aims to summarize the currently available clinical data for the approved rapid-onset opioids, which comprise different formulations of fentanyl, a μ-opioid receptor agonist with anaesthetic and analgesic properties. Administration routes for fentanyl in the management of BTP currently include the transmucosal and intranasal routes; an intrapulmonary formulation is also in development. The findings of this review suggest that the efficacy and safety of the approved rapid-onset opioids are comparable.

Oral trasmucosal fentanyl citrate for breakthrough pain treatment in cancer patients

INTRODUCTION

Breakthrough cancer pain has been defined as a transitory increase in pain intensity that occurs either spontaneously or in relation to a specific predictable or unpredictable trigger, despite relatively stable and adequately controlled background pain. The availability of supplemental doses of oral opioids, in addition to the continuous analgesic medication, is the main treatment suggested to manage pain flares.

AREAS COVERED

Oral transmucosal fentanyl citrate (OTFC) is the first product of a new generation of delivery systems, named rapid-onset opioids (ROOs), characterized by rapidity of effect and the short duration of analgesia. Controlled studies and long-term experience have shown that OTFC is an effective treatment for breakthrough pain management and its use should be considered in any patient experiencing breakthrough pain related to cancer.

EXPERT OPINION

The onset of action of OTFC - demonstrated to start within 15 min - and the short time to maximum concentration make it a useful indication for breakthrough pain; dose titration is commonly recommended. However, it is likely that patients receiving high doses of opioids for background analgesia will not be candidates for titration with minimal initial doses of OTFC, as they are opioid tolerant and the process would be time consuming.

Fentanyl for breakthrough pain: a systematic review

The purpose of this article is to systematically review the use of fentanyl as an analgesic for breakthrough pain. This article found that the oral transmucosal fentanyl (OTFC) had a quicker onset to analgesia than oral immediate-release opioids. Intranasal fentanyl (INFS) had a quicker onset to analgesia than buccal tablets, which in turn had a quicker onset to analgesia than OTFC. Patient acceptance and global rating of efficacy were greater for INFS than for buccal fentanyl. OTFC and INFS have been used effectively to reduce acute pain in children who are opioid-naive. Abuse and addiction to OTFC, fentanyl buccal tablets and INFS was low, owing to patient selection.

Pharmacokinetics, safety, and tolerability of ascending doses of sublingual fentanyl, with and without naltrexone, in Japanese subjects

This open-label, nonrandomized study assessed single and repeat ascending doses of a new sublingual fentanyl (SLF) formulation in 48 healthy Japanese opiate-naïve subjects (47 completed). Subjects received single-dose SLF 100, 200, 400, or 800 µg followed by 13 doses 6 hourly, at their dose level. Subjects taking repeat-dose 400 and 800 µg were pretreated with naltrexone in order to block opiate-receptor-mediated effects on respiration, monitored by pulse oximetry and transcutaneous pco(2). Sublingual fentanyl was rapidly and consistently absorbed. After single doses, median t(first) was 0.08 to 0.25 hours and t(max) 0.50 to 1.00 hours. After repeat dosing, median t(max) (t(max,ss)) was 0.50 to 2.00 hours. Plasma concentrations were dose proportional both after single and repeat dosing, and naltrexone appeared to have no effect on SLF pharmacokinetics. Plasma fentanyl reached steady state within the 72-hour dosing period and accumulation was approximately 2-fold. After single doses, effects on respiratory variables were evident after the 400-µg and 800-µg doses. Transcutaneous pco(2) was not helpful in detecting respiratory depression. Thus, SLF yielded rapid absorption of fentanyl and dose-proportional plasma concentrations that, for 400 µg and 800 µg, were within the typical analgesic range. Respiratory depression in these opioid-naïve volunteers was manageable with simple clinical measures.

Oral transmucosal fentanyl citrate: a novel agent for breakthrough pain related to cancer

Pain is problematic for many cancer patients. As more experience has been gained in treating cancer pain, breakthrough pain has been recognized as a phenomenon that occurs frequently in this population. Breakthrough pain is generally treated with a variety of short-acting opioids via a number of routes. Actiq (oral transmucosal fentanyl citrate) is a formulation of fentanyl citrate delivered via the transmucosal route in a sucrose base. Patients using this agent are instructed to paint the unit on the buccal mucosa in order to achieve relief. The onset of Actiq is reported to be equal to intravenous morphine. There are a wide variety of dosage forms available, allowing 74% of patients involved in clinical studies of the agent to titrate to an appropriate dose. The proper use, side effect profile and advantages/disadvantages will be reviewed for this agent.

Cytokines and cholinergic signals co-modulate surgical stress-induced changes in mood and memory

Inflammatory cytokines and the cholinergic system have been implicated in the effects of stressors on mood and memory; however, the underlying mechanisms involved and the potential interrelationships between these pathways remain unclear. To address these questions, we administered neuropsychological tests to 33 generally healthy surgery patients who donated blood samples several days prior to undergoing moderate surgery (baseline), on the morning of the surgery (i.e., a psychological stressor), and one day after surgery. Eighteen control subjects were similarly tested. Serum levels of inflammatory cytokines, acetylcholinesterase (AChE) activity, and the stressor-inducible AChE-R variant were measured. An elevation in anxiety levels, an increase in depressed mood, and a decline in declarative memory were observed on the morning of the surgery, prior to any medical intervention, and were exacerbated one day after surgery. The surgical stressor-induced elevated IL-1 beta levels, which contributed to the increased depressed mood and to the post-surgery increase in AChE-R expression. The latter increase, which was also predicted by pre-surgery AChE-R and post-surgery mood disturbances, was associated with exacerbated memory impairments induced by surgery. In addition, elevated levels of AChE-R on the morning of the surgery predicted the post-surgery elevation in IL-6 levels, which was associated with amelioration of the memory impairments induced by surgery. Taken together, these findings suggest that exposure to a surgical stressor induces a reciprocal up-regulation of AChE-R and pro-inflammatory cytokines, which are involved in regulating the surgery-induced mood and memory disturbances.

Evidence-Based Oral Transmucosal Fentanyl Citrate (OTFC®) Dosing Guidelines

OBJECTIVE

To review the evidence for dosing and efficacy of oral transmucosal fentanyl citrate in the management of pain and produce dosing guidelines.

DESIGN

The scientific literature pertaining to oral transmucosal fentanyl citrate was reviewed, focusing upon its pharmacology and clinical experience with use in cancer and noncancer pain. Emphasis was upon published, peer-reviewed English language articles.

RESULTS

Information was crucially examined and synthesized into guidelines for use and dosing of oral transmucosal fentanyl citrate in cancer and noncancer pain.

CONCLUSIONS

Oral transmucosal fentanyl citrate is a potent opioid delivery system, which, when used appropriately, is an effective treatment option for pain. Adherence to guidelines should promote its safe and efficacious use in a variety of clinical pain management settings.

[Safety and efficacy of oral trans-mucosal fentanyl citrate in the long-term treatment of breakthrough pain in oncology patients: the ECODIR study]

INTRODUCTION

Oral trans-mucosal fentanyl citrate (OTFC) is the one drug specifically developed for the management of breakthrough pain. This study assesses the long-term safety and efficacy of OTFC standard clinical conditions. Patients and methods. Six-month observational study performed on cancer patients with episodes of breakthrough pain. Safety was assessed by recording the advent of adverse events and efficacy by the evaluating the intensity of breakthrough pain.

RESULTS

174 cancer patients were recruited into the study. All adverse reactions reported were mild or moderate. OTFC was significantly faster (time to the commencement of pain relief: 12.7 +/- 11.4 vs 32.7 +/- 18.4 minutes; p < 0.001) and potent (post-treatment pain intensity: 3.4 +/- 1.5 vs 4.3 +/- 1.5; p < 0.001) than the previously-used drugs.

CONCLUSIONS

This observational study confirms the good safety profile of OTFC as well as its effectiveness over long-term period treatment of breakthrough pain.

The Pharmacokinetics of the Intravenous Formulation of Fentanyl Citrate Administered Orally in Children Undergoing General Anesthesia

The bioavailability of oral transmucosal fentanyl citrate (OTFC) in children is similar to that of fentanyl solution administered orally to adults. We hypothesized that administering an oral fentanyl solution to children would result in similar fentanyl plasma concentrations and pharmacokinetic variables as administering comparable doses of OTFC. In this pilot study, 10 healthy children requiring postoperative analgesia were enrolled. Each received the undiluted IV fentanyl formulation orally (approximately 10-15 microg/kg; maximum, 400 microg). Venous blood samples were collected from 15 to 600 min after administration. Pharmacokinetic variables were determined using noncompartmental analysis and were compared with a previously studied population of children who received a similar dose of OTFC. Pharmacokinetic variables for the orally administered IV fentanyl formulation were as follows: time to reach peak concentration = 1.7 +/- 1.6 h, peak concentration = 1.83 +/- 1.19 ng/mL, half-life = 4.7 +/- 2.8 h, area under the plasma concentration time curve = 6.46 +/- 3.96 h . ng(-1) . mL(-1), apparent oral volume of distribution (V/F) = 17.5 +/- 7.2 L/kg, apparent oral clearance (CL/F) = 3.33 +/- 2.25 L . kg(-1) . h(-1). Although both OTFC and orally administered IV fentanyl resulted in similar pharmacokinetic variables and plasma concentrations for a given dose, there was marked interpatient variability, particularly in the early hours after oral administration of the IV formulation of fentanyl. This suggests that this method of administration be used with caution until further data are available.

Clinical effects and plasma concentrations of fentanyl after transmucosal administration in three species of great ape

Fentanyl is approved for transmucosal use in the United States as a preanesthetic agent in human pediatric patients and in adults for breakthrough cancer pain. Using this formulation in three species of great ape, including eight orangutans (Pongo pygmaeus), nine chimpanzees (Pan troglodytes), and two gorillas (Gorilla gorilla), fentanyl was offered transmucosally at an intended dose of 10-15 microg/kg based on estimated body weight. The animals were trained to accept and suck slowly on a piece of placebo candy, given as a treat, after an overnight fast. On the day of the study, the animals were given the lollipop formulation of fentanyl. The resulting plasma concentrations of fentanyl supported transmucosal absorption, similar to that reported in humans. This study provides an alternative sedative regimen and yielded half-life data of transmucosal fentanyl in great apes. Although transmucosal fentanyl was a useful adjunct for sedating orangutans and gorillas, its acceptance by chimpanzees before chemical immobilization was suboptimal and unpredictable.

Oral transmucosal fentanyl citrate in the outpatient management of severe cancer pain crises: a retrospective case series

OBJECTIVE

This retrospective chart review evaluated the efficacy of oral transmucosal fentanyl citrate (OTFC) in an outpatient cancer pain center for patients experiencing severe exacerbations of pain that exceed usual breakthrough pain levels.

PATIENTS

Records were reviewed for all patients who received OTFC at M.D. Anderson's outpatient pain clinic over a three-month time period. OTFC was used in thirty-nine patients experiencing a recent onset of severe pain (> or =7 on a 0-10 scale). All patients had cancer, cancer-related pain syndromes, and were opioid tolerant with an oral morphine equivalent daily dosage (MEDD) of (> or =40 mg/day.

RESULTS

Prior to OTFC treatment, all patients reported a mean pain intensity of 9.0 (SD = 1.2). After OTFC treatment, patients reported a mean intensity of 3.0 (SD = 1.4), a significant reduction in pain intensity (P < 0.001). In most cases, OTFC averted the need for an emergency center visit, parenteral opioids, and hospital admission, which suggests that OTFC may be an effective alternative over intravenous opioids to rapidly titrate analgesia in selected opioid-tolerant cancer patients experiencing severe pain.

Simultaneous extraction and quantitation of fentanyl and norfentanyl from primate plasma with LC/MS detection

The quantitation of both fentanyl and its desalkyl metabolite, norfentanyl, in plasma using LC/MS has not been previously described. The detection and quantitation of fentanyl and norfentanyl was achieved using LC/MS detection. The liquid-liquid extraction used toluene as the organic phase. Chromatography was carried out using a Zirchrom-PBD (50 mm x 2.1 mm, 3 microm) column with a mobile phase of acetonitrile-ammonium acetate (10 mM), citrate (0.1 mM, pH 4.4) (45:55, v/v) with a flow rate of 0.3 ml/min. Mass spectroscopy detection was performed using ESI in the positive mode. The LOQ for fentanyl was 25 pg/ml and norfentanyl was 50 pg/ml. For the concentrations of 75, 250, and 750 pg/ml, respectively, fentanyl had inter-day precisions of 6.6, 7.2, and 6.6% with accuracies of 4.0, 5.1, and 5.1% and intra-day precisions of 1.6, 1.9, and 1.9% with accuracies of 11.6, 9.4, and 8.4%, and norfentanyl had inter-day precisions of 7.4, 0.3, and 0.7% with accuracies of 9.1, 8.8, and 12.3% and intra-day precisions of 5.3, 1.4, and 0.1% with accuracies of 10.9, 8.9, and 12.8%. The recoveries of fentanyl were 85, 92, and 75% and of norfentanyl were 40, 49, and 46% at the 75, 250, and 750 pg/ml concentrations, respectively.

Self-treatment with oral transmucosal fentanyl citrate to prevent emergency room visits for pain crises: patient self-reports of efficacy and utility

Ninety (90) patients with chronic pain who were treated with a long-acting opioid were instructed on use of oral transmucosal fentanyl citrate (OTFC) for self-treatment of emergency pain flares. Eighty-six (95.6%) believed OTFC was effective and safe for self-treatment of emergency pain flares, and 71 (78.8%) believed they had prevented one or more emergency room visits for treatment of pain flares. A subgroup of 45 patients who had collectively used OTFC for 375 months, based on their past experience, estimated they had prevented 1.26 emergency room visits per month per patient. OTFC should be further studied for cost-savings and effectiveness in self-treatment of emergency pain flares.

Oral premedication with fentanyl may be a safe and effective alternative to oral midazolam

BACKGROUND AND OBJECTIVE

Although midazolam is commonly given orally to infants and small children for premedication, the taste is sometimes unacceptable even when mixed with syrup. We tested the efficacy and safety of oral fentanyl compared with oral midazolam in a randomized open-label study.

METHODS

Fifty-one children, aged 12-107 months and weighing 10-25 kg, were randomly assigned to fentanyl or midazolam treatment groups. Midazolam (5 mg) or fentanyl (0.1 mg) was given orally from a small bottle with a small orifice 30 min before transfer to the preoperative holding room. The excitation-sedation conditions of the patients were assessed before and after general anaesthesia.

RESULTS

The preoperative scores did not differ significantly between the two groups. No major complications were observed in either group. Postoperative vomiting occurred in 5 of 27 (18.5%) patients treated with oral fentanyl and in none of 24 of those treated with midazolam.

CONCLUSIONS

Oral administration of fentanyl 30 min before entrance to the holding room for an operation from a bottle with a small orifice is a premedication option for children between 1 and 8 yr of age.

Oral mucosal drug delivery: clinical pharmacokinetics and therapeutic applications

Oral mucosal drug delivery is an alternative method of systemic drug delivery that offers several advantages over both injectable and enteral methods. Because the oral mucosa is highly vascularised, drugs that are absorbed through the oral mucosa directly enter the systemic circulation, bypassing the gastrointestinal tract and first-pass metabolism in the liver. For some drugs, this results in rapid onset of action via a more comfortable and convenient delivery route than the intravenous route. Not all drugs, however, can be administered through the oral mucosa because of the characteristics of the oral mucosa and the physicochemical properties of the drug. Several cardiovascular drugs administered transmucosally have been studied extensively. Nitroglycerin is one of the most common drugs delivered through the oral mucosa. Research on other cardiovascular drugs, such as captopril, verapamil and propafenone, has proven promising. Oral transmucosal delivery of analgesics has received considerable attention. Oral transmucosal fentanyl is designed to deliver rapid analgesia for breakthrough pain, providing patients with a noninvasive, easy to use and nonintimidating option. For analgesics that are used to treat mild to moderate pain, rapid onset has relatively little benefit and oral mucosal delivery is a poor option. Oral mucosal delivery of sedatives such as midazolam, triazolam and etomidate has shown favourable results with clinical advantages over other routes of administration. Oral mucosal delivery of the antinausea drugs scopolamine and prochlorperazine has received some attention, as has oral mucosal delivery of drugs for erectile dysfunction. Oral transmucosal formulations of testosterone and estrogen have been developed. In clinical studies, sublingual testosterone has been shown to result in increases in lean muscle mass and muscle strength, improvement in positive mood parameters, and increases in genital responsiveness in women. Short-term administration of estrogen to menopausal women with cardiovascular disease has been shown to produce coronary and peripheral vasodilation, reduction of vascular resistance and improvement in endothelial function. Studies of sublingual administration of estrogen are needed to clarify the most beneficial regimen. Although many drugs have been evaluated for oral transmucosal delivery, few are commercially available. The clinical need for oral transmucosal delivery of a drug must be high enough to offset the high costs associated with developing this type of product. Drugs considered for oral transmucosal delivery are limited to existing products, and until there is a change in the selection and development process for new drugs, candidates for oral transmucosal delivery will be limited.

Controversial issues in adult and paediatric ambulatory anaesthesia: is there a role for alpha-2 agonists in conscious sedation in adults and paediatric ambulatory surgical practice?

Ambulatory surgery has come to the fore in recent years, guided by the twin forces of healthcare economics and pharmacological innovations. In this review the authors will focus on alpha2-adrenergic agonists, a new class of sedative/analgesic agents and their possible application for conscious sedation in the ambulatory care setting. To put the alpha2-agonists into clinical context, we will discuss the currently available agents for general anaesthesia as well as for conscious sedation and their respective drawbacks. Thereafter we will compare and contrast the use of alpha2-agonists with clinically available agents, and speculate as to the direction this field is likely to take in the future.