Clinical trial: a dose-response study of fospropofol disodium for moderate sedation during colonoscopy

New sedatives and analgesic drugs for gastrointestinal endoscopic procedures

Procedural sedation has become increasingly common in endoscopy. Sedatives and analgesics induce anxiolysis and amnesia. In addition, an appropriate level of sedation is necessary for safe procedures including therapeutic endoscopy. Midazolam and propofol are the most commonly used drugs in sedative endoscopy. In recent years, the need to ascertain the safety and effectiveness of sedation has increased in practice. Therefore, new sedatives and analgesic drugs for optimal sedative endoscopy, have recently emerged. This article reviews the characteristics of sedatives and analgesics, and describes their clinical use in gastrointestinal endoscopy.

Efficacy and Safety of Fospropofol Disodium for Injection in General Anesthesia Induction for Adult Patients: A Phase 3 Trial

Background: Fospropofol disodium for injection (Fospropofol_FD) is a prodrug that is metabolized into propofol to produce a general anesthesia effect when administered intravenously.

Objective: This study aimed to assess the efficacy and safety of Fospropofol_FD in comparison with propofol medium/long-chain fat emulsion injections (propofol-MCT/LCT) for general anesthesia induction in adult patients undergoing elective surgeries.

Setting: Nine academic medical centers in China.

Method: This multicenter, randomized, double-blind, double-simulated, controlled, and non-inferiority trial evaluated 540 eligible adult patients randomly assigned (2:1) to the intervention (20 mg/kg Fospropofol_FD) or control (2 mg/kg propofol-MCT/LCT) groups.

Main Outcome Measure: The primary efficacy endpoint was the success rate, defined as a Modified Observer’s Assessment of Alertness/Sedation Scale score of 1 within 5 min after study drug administration. The safety endpoints consisted of adverse events (AEs) related to consciousness, cognitive function, hemodynamic status, liver and kidney function, and blood tests.

Results: A total of 347 (96.3%) and 175 (97.2%) patients in the intervention and control groups, respectively, completed the study. The success rate for the primary outcome was 97.7% for both study drugs. The most frequent AEs in the intervention group were abnormal feeling (62.0%), blood pressure reduction (13.5%), and injection site pain (13.3%). No AEs related to consciousness and mental and cognitive functions or serious adverse events were reported.

Conclusion: Fospropofol_FD (20 mg/kg) is not inferior to propofol-MCT/LCT (2 mg/kg) in general anesthesia induction for American Society of Anesthesiologists (ASA) physical status I-II adult patients undergoing elective surgeries. It is safe and effective for clinical use under anesthesiologist monitoring.

Impact on Practice Statement: Fospropofol_FD can produce a general anesthesia effect and reduce the incidence of pain at the site of injection.

Syntheses of Analogues of Propofol: A Review

Propofol (2,6-diisopropylphenol) is an intravenous sedative/hypnotic agent that is used extensively for introduction and maintenance of general anaesthesia, sedation of critically ill patients and procedural sedation (e.g., endoscopy). Propofol has a rapid onset and offset of action and shows only minimal accumulation upon prolonged use. Propofol is only sparingly soluble in water and is currently marketed in 10% soybean oil-based lipid emulsion. Propofol’s anaesthetic properties were discovered over forty years ago, and it has been in clinical use for over thirty years. The main use of propofol remains as an anaesthetic but, over the years, analogues have been developed with varying properties from anticancer, anticonvulsant and antioxidant. In addition, large synthetic efforts have been made towards improving propofol’s water-solubility, its activity, and elucidating its structure–activity­ relationship and exact mechanism of action have been made. This review provides an overview of the research pertaining to propofol-like molecules and covers the efforts of synthetic chemists towards propofol analogues over the last 40 years.

1 Introduction

2 History

3 Early Work

4 Improving Water Solubility

5 The Importance of the Phenol

6 Exploring the Structure–Activity Relationship and Attempts to Improve Activity

7 Anticancer Activity

8 Anticonvulsant Properties

9 Antioxidant Activity

10 Photoactive Labelling to Elucidate Mechanism of Action

11 Photoregulation

12 Conclusion

The preclinical pharmacological study on HX0969W, a novel water-soluble pro-drug of propofol, in rats

Background

Propofol is the most widely used intravenous sedative-hypnotic anesthetic in clinical practice. However, many serious side effects have been related to its lipid emulsion formulation. The pro-drug design approach was used to develop the water-soluble propofol, which could effectively resolve the limitations associated with the lipid emulsion formulation. Thus, the new water-soluble pro-drug of propofol, HX0969W, was designed and synthesized. The objective of this study was to conduct preclinical pharmacological studies on this novel water-soluble pro-drug of propofol.

Methods

The assessment of the loss of the righting reflex (LoRR) was used for the pharmacodynamic study, and liquid chromatography-tandem mass spectrometry and high-performance liquid chromatography- fluorescence were used for the pharmacokinetic study.

Results

The potency of HX0969W (ED₅₀ [95% CI], 46.49 [43.89–49.29] mg/kg) was similar to that of fospropofol disodium (43.66 [43.57–43.75] mg/kg), but was lower than that of propofol (4.82 [4.8–14.82] mg/kg). Administered with a dose of 2-fold ED₅₀, propofol required a shorter time to cause LoRR than that of HX0969W and fospropofol. However, the LoRR duration was significantly longer in response to the administration of HX0969W and fospropofol disodium than that caused by propofol. In the pharmacokinetic study, the C_max of fospropofol was higher than that of HX0969W. HX0969W had a shorter mean residual time and a rapid clearance rate than that of fospropofol disodium. There was no significant difference between the T_max of the propofol whether it was released by HX0969W or fospropofol disodium; the C_max of propofol released by HX0969W was similar to that of propofol, which was higher than the propofol released by fospropofol disodium.

Evaluating Patient-Centered Outcomes in Clinical Trials of Procedural Sedation, Part 1 Efficacy: Sedation Consortium on Endpoints and Procedures for Treatment, Education, and Research Recommendations

The Sedation Consortium on Endpoints and Procedures for Treatment, Education, and Research, established by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks public-private partnership with the US Food and Drug Administration, convened a meeting of sedation experts from a variety of clinical specialties and research backgrounds with the objective of developing recommendations for procedural sedation research. Four core outcome domains were recommended for consideration in sedation clinical trials: (1) safety, (2) efficacy, (3) patient-centered and/or family-centered outcomes, and (4) efficiency. This meeting identified core outcome measures within the efficacy and patient-centered and/or family-centered domains. Safety will be addressed in a subsequent meeting, and efficiency will not be addressed at this time. These measures encompass depth and levels of sedation, proceduralist and patient satisfaction, patient recall, and degree of pain experienced. Consistent use of the recommended outcome measures will facilitate the comprehensive reporting across sedation trials, along with meaningful comparisons among studies and interventions in systematic reviews and meta-analyses.

New Hypnotic Drug Development and Pharmacologic Considerations for Clinical Anesthesia

Since the public demonstration of ether as a novel, viable anesthetic for surgery in 1846, the field of anesthesia has continually sought the ideal anesthetic-rapid onset, potent sedation-hypnosis with a high therapeutic ratio of toxic dose to minimally effective dose, predictable clearance to inactive metabolites, and minimal side effects. This article aims to review current progress of novel induction agent development and provide an update on the most promising drugs poised to enter clinical practice. In addition, the authors describe trends in novel agent development, implications for health care costs, and implications for perioperative care.

Prospective, randomized, placebo-controlled trial evaluating the efficacy and safety of propofol sedation by anesthesiologists and gastroenterologist-led teams using computer-assisted personalized sedation during upper and lower gastrointestinal endoscopy

BACKGROUND AND AIM

No randomized controlled studies comparing propofol versus no sedation have been reported. Comparative data demonstrating the efficacy and safety of propofol sedation by anesthesiologists (ANES), and gastroenterologist-led teams (GLT) using computer-assisted personalized sedation (CAPS), during routine gastrointestinal (GI) endoscopy in Japan do not exist. We aimed to demonstrate the safety and efficacy of propofol sedation versus no sedation (PLCB) when propofol is given by ANES or GLT, during routine GI endoscopy.

METHODS

Two hundred and seventy two American Society of Anesthesiologists (ASA) class I or II adults were prospectively enrolled in this multicenter study and randomized into three groups (PLCB, ANES, GLT). Ability to maintain moderate sedation, defined as MOAA/S scores of 2-4 for ≥50% of all MOAA/S measurements from scope-in to scope-out, was the primary endpoint. Secondary endpoints included patient (PSSI) and clinician (CSSI) satisfaction.

RESULTS

Proportion of subjects maintained in moderate sedation by ANES (88.1%) and GLT (94.5%) was significantly higher than PLCB (21.6%; P < 0.001); there was no difference between the ANES and GLT groups (P = 0.116). Mean PSSI scores for subjects sedated by ANES (81.2 ± 12.5) and GLT (80.8 ± 14.1) were significantly higher than PLCB (65.3 ± 19.7; P < 0.001) and mean CSSI scores were also significantly higher in both active treatment groups (75.5 ± 10.2, 77.9 ± 10.3) than PLCB (60.8 ± 18.6; P < 0.001).

CONCLUSION

Moderate sedation can be achieved and maintained with propofol, improving both patient and physician satisfaction, when propofol is given by an anesthesiologist or a gastroenterologist-led team using CAPS.

Efficacy Outcome Measures for Procedural Sedation Clinical Trials in Adults: An ACTTION Systematic Review

Successful procedural sedation represents a spectrum of patient- and clinician-related goals. The absence of a gold-standard measure of the efficacy of procedural sedation has led to a variety of outcomes being used in clinical trials, with the consequent lack of consistency among measures, making comparisons among trials and meta-analyses challenging. We evaluated which existing measures have undergone psychometric analysis in a procedural sedation setting and whether the validity of any of these measures support their use across the range of procedures for which sedation is indicated. Numerous measures were found to have been used in clinical research on procedural sedation across a wide range of procedures. However, reliability and validity have been evaluated for only a limited number of sedation scales, observer-rated pain/discomfort scales, and satisfaction measures in only a few categories of procedures. Typically, studies only examined 1 or 2 aspects of scale validity. The results are likely unique to the specific clinical settings they were tested in. Certain scales, for example, those requiring motor stimulation, are unsuitable to evaluate sedation for procedures where movement is prohibited (e.g., magnetic resonance imaging scans). Further work is required to evaluate existing measures for procedures for which they were not developed. Depending on the outcomes of these efforts, it might ultimately be necessary to consider measures of sedation efficacy to be procedure specific.

Efficacy and Safety of FospropofolFD Compared to Propofol When Given During the Induction of General Anaesthesia: A Phase II, Multi-centre, Randomized, Parallel-Group, Active-Controlled, Double-Blind, Double-Dummy Study

The present phase II study aimed to compare the efficacy and safety of fospropofol disodium for injection (FospropofolFD ) and propofol when given during the induction of general anaesthesia in patients scheduled for elective surgery. FospropofolFD is a water-soluble prodrug of propofol. Approved by the Ethical Committee, 240 participants aged 18-65 years were equally randomly allocated to receive an intravenous bolus of FospropofolFD 20 mg/kg or propofol 2 mg/kg without any anaesthetic pre-treatment. The primary efficacy end-point was the sedation success rate within 5 min. after administering investigational drugs (the sedation success is defined as obtaining Modified Observer's Assessment of Alertness/Sedation scale score of 1). All the participants completed the induction and intubation within 25 min. after administration. The sedation success rates within 5 min. after administration of FospropofolFD 20 mg/kg and propofol 2 mg/kg were 94.50% versus 100% in the intention-to-treat population and 95.10% versus 100% in the per-protocol population, respectively. The non-inferiority test obtained a p-value less than 0.025, and the lower limits of the one-sided 97.5% confidence interval were more than -0.09. This meant that FospropofolFD 20 mg/kg was considered non-inferior to propofol 2 mg/kg for the primary efficacy end-point. Compared with propofol 2 mg/kg, FospropofolFD 20 mg/kg had a slower sedation efficacy. No serious adverse events were observed in the two groups. The sedation success rate within 5 min. after administration of FospropofolFD 20 mg/kg was non-inferior to propofol 2 mg/kg, and FospropofolFD 20 mg/kg can be used for the induction of general anaesthesia safely.

Synthesis and evaluation of hydroponically alginate nanoparticles as novel carrier for intravenous delivery of propofol

Commercial lipid emulsion of propofol (CLE) has several drawbacks including pain on injection and emulsion instability. In this paper, a novel nanocarrier system is introduced to improve stability and solubility of the poorly soluble anesthetic drug, propofol, for intravenous administration. In this paper, alginate is modified using a facile method in which the carboxylic group of alginate is grafted to octanol. The octanol-grafted alginate (Alg-C8) is then employed to prepare nanoparticles which are subsequently used for encapsulation of propofol. The nanoparticles are analyzed for their pH, osmolarity, particle size, stability, morphology and sleep recovery and the results are compared with CLE as control. It is revealed that nanoparticles have the average particle size of 180 nm ± 1.2 and spherical morphology which is less than CLE while their pH, osmolarity and profile of release of formulated nanoparticles are similar to those of CLE. In addition, the results show good chemical and physical storage stability for the nanoparticles at room temperature for at least 6 months compared to CLE as control. The animal sleep recovery test on rats shows no significant difference in time of unconsciousness and recovery of the righting reflex between nanoparticles and CLE. It is concluded that encapsulated nanoparticles introduced here could be a promising clinical intravenous system for delivery of poorly soluble anesthetic propofol. In addition, this study provides an efficient and facile method for preparing a carrier system for water insoluble drugs.

A randomized open-label phase I pilot study of the safety and efficacy of total intravenous anesthesia with fospropofol for coronary artery bypass graft surgery

OBJECTIVE

To determine safety and efficacy of the water-soluble prodrug fospropofol for anesthesia in cardiac surgery and to compare the pharmacodynamic profiles of fospropofol and propofol.

DESIGN

Pilot study and a prospective, phase I, open-label, single-center, randomized clinical trial.

SETTING

University hospital; single institution.

PARTICIPANTS

Sixteen patients undergoing elective first-time coronary artery bypass surgery.

INTERVENTIONS

Patients were randomized to receive total intravenous anesthesia with fospropofol (n = 8) or propofol (n = 8) combined with alfentanil as total intravenous anesthesia. Bispectral index, arterial blood pressure, and heart rate were recorded continuously, and pulmonary artery catheter measurements were obtained. Plasma concentrations of formate, phosphate, and Ca(2+) were monitored closely. Safety and tolerability were assessed by adverse events, neurologic examinations, clinical laboratory tests, and vital signs.

MEASUREMENTS AND MAIN RESULTS

The total doses of fospropofol and propofol during anesthesia were 11.3±2.5 and 4.4±1.0 mg/kg/h, respectively. According to the achieved bispectral index (BIS) values, fospropofol was as effective as propofol in providing general anesthesia and sedation. There were no clinical signs of formate toxicity in the fospropofol group. The only treatment-related adverse event after administration of fospropofol was a transient burning sensation in the perineal and perianal region during induction of sedation or anesthesia.

CONCLUSIONS

Fospropofol could be used to provide general anesthesia in patients undergoing coronary artery bypass graft surgery. Further larger studies are needed to prove the safety of fospropofol when given to provide general anesthesia for major cardiac surgical procedures.

An improved design of water-soluble propofol prodrugs characterized by rapid onset of action

BACKGROUND

Phosphate ester prodrugs of propofol (fospropofol, HX0969W) were designed to avoid the unsatisfactory water solubility of the parent drug. However, in previous clinical trials, there were reported prodrug side effects such as paresthesia and pruritus. The accumulation of a phosphate ester component was found to be the main culprit. To exclude this potential risk, we designed 2 amino acid propofol prodrugs (HX0969-Gly-F3, HX0969-Ala-HCl) based on the lead compound (HX0969) by introducing the amino acid group into the structures of the propofol prodrugs. We hypothesized that the improved propofol prodrugs could not only eliminate those adverse effects but also retain their rapid action and good water solubility.

METHODS

The lead compound HX0969 was synthesized by the sodium borohydride-iodine system. HX0969W, HX0969-Gly-F3, and HX0969-Ala-HCl were synthesized from HX0969. The solubility of fospropofol, HX0969W, HX0969-Gly-F3, and HX0969-Ala-HCl in normal saline was tested. The bioconversions from those prodrugs to propofol in different physiological media (rat plasma, rhesus monkey plasma, and rat hepatic microsomes) were determined in vitro. An in vivo test in the rats was performed to measure the 50% effective dose (ED50) of the 4 propofol prodrugs. Their action onset time and duration time were also measured after their equipotent doses were given.

RESULTS

(1) The water solubility of fospropofol, HX0969W, HX0969-Gly-F3, and HX0969-Ala-HCl was 461.46 ± 26.40 mg/mL, 189.45 ± 5.02 mg/mL, 49.88 ± 0.58 mg/mL, and 245.99 ± 4.83 mg/mL, respectively; (2) The hydrolysis tests in both the rat plasma and the rhesus monkey plasma revealed that the 2 amino acid prodrugs released propofol to a greater extent at a more rapid rate than the 2 phosphate prodrugs during the testing period of 5 hours. All 4 prodrugs released propofol rapidly in the presence of rat hepatic enzymes; (3) Compared with the previous prodrugs (fospropofol, HX0969W), the 2 novel compounds (HX0969-Gly-F3, HX0969-Ala-HCl) had a much shorter onset time when a much lower dose was given.

CONCLUSIONS

Application of the amino acid group to the propofol prodrug can make the prodrug have good water solubility and a more rapid onset of action. In rat plasma, the 2 improved amino acid prodrugs (HX0969-Ala-HCl, HX0969-Gly-F3) had a more rapid rate of propofol release than the 2 phosphate ester prodrugs (fospropofol, HX0969W). The in vivo tests showed that HX0969-Ala-HCl and HX0969-Gly-F3 given IV could have a more rapid onset of action in a smaller dose than fospropofol and HX0969W. This novel design can enhance the efficiency of prodrugs converting to propofol.

A comparison of fospropofol to midazolam for moderate sedation during outpatient dental procedures

Moderate intravenous (IV) sedation combined with local anesthesia is common for outpatient oral surgery procedures. An ideal sedative agent must be safe and well tolerated by patients and practitioners. This study evaluated fospropofol, a relatively new sedative/hypnotic, in comparison to midazolam, a commonly used benzodiazepine, for IV moderate sedation during oral and maxillofacial surgery. Sixty patients were randomly assigned to either the fospropofol or the midazolam group. Each participant received 1 μg/kg of fentanyl prior to administration of the selected sedative. Those in the fospropofol group received an initial dose of 6.5 mg/kg, with 1.6 mg/kg supplemental doses as needed. Those in the midazolam group received initial doses of 0.05 mg/kg, followed by 0.02 mg/kg supplemental doses. The quality of sedation in each patient was evaluated with regard to (a) onset of sedation, maintenance, and recovery profile; (b) patient and surgeon satisfaction; and (c) hemodynamic stability and adverse effects. The fospropofol group demonstrated shorter physical recovery times than midazolam patients, taking a mean of 11.6 minutes versus 18.4 minutes for physical recovery (P = .007). Cognitive recovery comparison did not find any difference with a mean of 7.5 minutes versus 8.8 minutes between the 2 drug groups (P = .123). The fospropofol group had a higher rate of local anesthetic injection recall (90.5 vs 44.4%, P = .004). Other parameters of recall were comparable. Two adverse effects demonstrated significance, with more patients in the midazolam group experiencing tachycardia (48.2 vs 9.4%, P = .001), and more patients in the fospropofol group experiencing perineal discomfort (40.6 vs 0, P < .001). No significant difference was found in any other measures of sedation safety, maintenance, or satisfaction. Fospropofol, when administered intravenously by a dentist anesthesiologist at the indicated dose in this study, appears to be a safe, well-tolerated alternative to midazolam for intravenous moderate sedation during minor oral surgery procedures.

Sedation in gastrointestinal endoscopy: current issues

Diagnostic and therapeutic endoscopy can successfully be performed by applying moderate (conscious) sedation. Moderate sedation, using midazolam and an opioid, is the standard method of sedation, although propofol is increasingly being used in many countries because the satisfaction of endoscopists with propofol sedation is greater compared with their satisfaction with conventional sedation. Moreover, the use of propofol is currently preferred for the endoscopic sedation of patients with advanced liver disease due to its short biologic half-life and, consequently, its low risk of inducing hepatic encephalopathy. In the future, propofol could become the preferred sedation agent, especially for routine colonoscopy. Midazolam is the benzodiazepine of choice because of its shorter duration of action and better pharmacokinetic profile compared with diazepam. Among opioids, pethidine and fentanyl are the most popular. A number of other substances have been tested in several clinical trials with promising results. Among them, newer opioids, such as remifentanil, enable a faster recovery. The controversy regarding the administration of sedation by an endoscopist or an experienced nurse, as well as the optimal staffing of endoscopy units, continues to be a matter of discussion. Safe sedation in special clinical circumstances, such as in the cases of obese, pregnant, and elderly individuals, as well as patients with chronic lung, renal or liver disease, requires modification of the dose of the drugs used for sedation. In the great majority of patients, sedation under the supervision of a properly trained endoscopist remains the standard practice worldwide. In this review, an overview of the current knowledge concerning sedation during digestive endoscopy will be provided based on the data in the current literature.

[Fospropofol: A new prodrug of propofol]

The development of new propofol formulations has advanced rapidly in the last ten years with the achievement of the marketing a new prodrug of propofol: fospropofol, pharmacologically different from the original compound. It is a water soluble compound that requires metabolism of the prodrug to propofol, which leads to a time delay between its administration and the appearance of its pharmacological effect. Its pharmacokinetic and pharmacodynamic characteristics are different to the original formula. Due to its formulation it does not cause pain on intravenous injection, does not lead to hyperlipidaemia or excess bacterial growth. Although it is currently unavailable in Spain, it has been approved by the FDA (American Food and Drug Administration) for sedation in controlled care in diagnostic and therapeutic procedures in adults. It must only be administered by personnel qualified to administer anaesthesia, and the patients must be monitored throughout the whole procedure.

Receptor specificity defines algogenic properties of propofol and fospropofol

BACKGROUND

Propofol-evoked injection site pain is not observed with fospropofol. We hypothesized that unlike propofol, fospropofol does not activate the irritant receptor, transient receptor potential 1 (TRPA1).

METHODS

We tested the hypothesis using electrophysiology and behavioral studies.

RESULTS

Our data demonstrate that propofol (100 μM) evokes an inward current only in TRPA1-expressing neurons. However, fospropofol (100 μM and 1 mM) is unable to evoke depolarizing currents in either TRPA1-positive or TRPA1-negative neurons. Both propofol and fospropofol produced general anesthesia.

CONCLUSIONS

The lack of algogenic activity in fospropofol is most likely the result of its inability to activate TRPA1 on nociceptors.

Perspectives on the role of fospropofol in the monitored anesthesia care setting

Monitored anesthesia care (MAC) is a safe, effective, and appropriate form of anesthesia for many minor surgical procedures. The proliferation of outpatient procedures has heightened interest in MAC sedation agents. Among the most commonly used MAC sedation agents today are benzodiazepines, including midazolam, and propofol. Recently approved in the United States is fospropofol, a prodrug of propofol which hydrolyzes in the body by alkaline phosphatase to liberate propofol. Propofol liberated from fospropofol has unique pharmacological properties, but recently retracted pharmacokinetic (PK) and pharmacodynamic (PD) evaluations make it difficult to formulate clear conclusions with respect to fospropofol's PK/PD properties. In safety and efficacy clinical studies, fospropofol demonstrated dose-dependent sedation with good rates of success at doses of 6.5 mg/kg along with good levels of patient and physician acceptance. Fospropofol has been associated with less pain at injection site than propofol. The most commonly reported side effects with fospropofol are paresthesia and pruritus. Fospropofol is a promising new sedation agent that appears to be well suited for MAC sedation, but further studies are needed to better understand its PK/PD properties as well its appropriate clinical role in outpatient procedures.

Fospropofol Disodium for Sedation in Elderly Patients Undergoing Flexible Bronchoscopy

BACKGROUND: Fospropofol disodium is a water-soluble prodrug of propofol. A subset analysis was undertaken of elderly patients (≥65 y) undergoing flexible bronchoscopy, who were part of a larger multicenter, randomized, double-blind study. METHODS: Patients received fentanyl citrate (50 mcg) followed by fospropofol at initial (4.88mg/kg) and supplemental (1.63mg/kg) doses. The primary end point was sedation success (3 consecutive Modified Observer's Assessment of Alertness/Sedation scores of ≤4 and procedure completion without alternative sedative or assisted ventilation). Treatment success, time to fully alert, patient and physician satisfaction, and safety/tolerability were also evaluated. RESULTS: In the elderly patients subset (n=61), sedation success was 92%, the mean time to fully alert was 8.0±10.9 min, and memory retention was 72% during recovery, and these were comparable with the younger patients subgroup (age, <65 y). Sedation-related adverse events occurred in 23% of the elderly and 18% of the younger patients (age, <65 y) group. Hypoxemia occurred in 26% of the elderly and 18% of the younger patients group, but no escalation of care was required. CONCLUSIONS: Fospropofol provided safe and effective sedation, rapid time to fully alert, and high satisfaction in this elderly subset undergoing flexible bronchoscopy, which was comparable with outcomes in younger patients.

Safety evaluation of fospropofol for sedation during minor surgical procedures

STUDY OBJECTIVE

To evaluate the safety of intravenous (IV) fospropofol when used to provide minimal to moderate sedation in patients undergoing minor surgical procedures.

DESIGN

Phase 3, open-label, single-arm study.

SETTING

Multi-center.

PATIENTS

123 ASA physical status I, II, III, and IV patients, aged>or=18 years.

INTERVENTIONS

Patients were pretreated with fentanyl 50 microg before receiving an initial dose of IV fospropofol 6.5 mg/kg. Patients could receive up to 5 supplemental doses of fospropofol 1.63 mg/kg to reach a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score<or=4 to allow the start of the procedure and to maintain adequate sedation levels during the procedure.

MEASUREMENTS

Study endpoints included measures of sedation depth, requirement for supplemental sedative doses, use of alternative sedatives, and the frequency and nature of treatment-emergent and sedative-related adverse events.

MAIN RESULTS

A mean of 2.4 supplemental doses of fospropofol was administered, and in 60% of patients, two or fewer supplemental doses of fospropofol were sufficient to initiate and complete the procedure. Alternative sedative medication was administered in 6 of 123 patients (4.9%). Mean (SD) MOAA/S score during the procedure was 3.8 (0.5). Sixty-one percent (61%) of patients had a MOAA/S score of 5 (fully alert) within two minutes after the end of the procedure. Few patients (7 of 123; 5.7%) had MOAA/S scores of 0 to 1 (deep sedation) during the procedure, and all 7 were either ASA physical status I (n=1) or II (n=6). The most common treatment-related adverse events (TRAEs) were self-limited: paresthesias (62.6%) and pruritus (27.6%). Five patients experienced sedation-related adverse events, including hypotension (n=4), bradycardia (concurrently with hypotension and managed with atropine; n=1), or hypoxemia (less than one min and managed with chin lift and verbal stimulation; n=1). Twenty patients with previous or existing hepatic disease (ranging from minimal to severe) and 5 patients with severe renal impairment had adverse events similar to the overall population. No deaths were reported, and no patient discontinued the study due to adverse events.

CONCLUSION

An initial dose of IV fospropofol 6.5 mg/kg with supplemental doses was safe and well-tolerated as moderate sedation for use in minor surgical procedures.

Sedation: not quite that simple

The number of diagnostic and therapeutic interventions performed under sedation is growing rapidly. While providing patients with an improved experience secondary to anxiolysis, analgesia, and amnesia, sedation also puts them at risk for associated cardiorespiratory and other complications. Several medications are available for sedation, all of which have unique advantages and disadvantages. The combination of patient characteristics, procedural factors, and side effects associated with each medication places each patient at risk and therefore, vigilance during sedation cannot be overemphasized. Due vigilance includes proper monitoring, training, staffing, and equipment, all of which are essential to the safe delivery of sedation.

The changing faces of endoscopic sedation

The practice of sedation for digestive endoscopy continues to evolve throughout the world. In many countries, there is a trend for increased utilization of sedation during routine endoscopic procedures. Sedation improves patient satisfaction with endoscopy and the willingness to comply with screening guidelines and it improves the quality of examination. Moderate sedation, using a benzodiazepine and an opioid, remains the standard method of sedation in most areas of the world, although propofol, a short-acting hypnotic agent, is being used increasingly in some countries. Controversy regarding the feasibility of endoscopist-directed propofol administration continues, in spite of overwhelming evidence supporting this practice. In the USA, recent revisions in policy by the Centers for Medicare and Medicaid Services may threaten the practice of endoscopist-directed propofol administration. In this article, future trends in sedation practice, including fospropofol and computer-assisted personalized sedation, are discussed.

Fospropofol

Fospropofol (fospropofol disodium), a sedative/hypnotic agent, is a water-soluble prodrug of propofol, metabolized in vivo to produce liberated propofol (producing the sedative effect), phosphate and formaldehyde. Intravenous fospropofol 6.5 mg/kg was significantly more effective than fospropofol 2.0 mg/kg (a placebo surrogate) as sedation in patients undergoing colonoscopy or flexible bronchoscopy, with regard to the primary endpoint of sedation success rate in randomized, double-blind, phase III trials. In patients undergoing colonoscopy, the sedation success rate was >3-fold higher among fospropofol 6.5 mg/kg (n = 158) than fospropofol 2.0 mg/kg recipients (n = 102). Similar results were observed in patients undergoing flexible bronchoscopy; the sedation success rate was >3-fold greater among fospropofol 6.5 mg/kg (n = 150) than among fospropofol 2.0 mg/kg recipients (n = 102). Fospropofol was generally well tolerated in clinical trials. Adverse events were mostly of mild to moderate severity, and were transient and self-limiting. Patients undergoing flexible bronchoscopy appeared to have a higher rate of sedation-related adverse events requiring airway assistance than did those undergoing colonoscopy or minor procedures.

Bronchoscopy: What critical care nurses need to know

Although bronchoscopies have been performed for over a century and are relatively safe when practice guidelines are followed, they are invasive and a real source of anxiety and fear for the patient. The role of the critical care nurse is essential to a successful outcome. This article provides an overview of the main diagnostic and therapeutic indications, contraindications, and possible complications. Also discussed are patient education; patient and staff safety; and considerations before, during, and after the procedure.

Sedation and analgesia in gastrointestinal endoscopy: What’s new?

Various types of sedation and analgesia technique have been used during gastrointestinal endoscopy procedures. The best methods for analgesia and sedation during gastrointestinal endoscopy are still debated. Providing an adequate regimen of sedation/analgesia might be considered an art, influencing several aspects of endoscopic procedures: the quality of the examination, the patient’s cooperation and the patient’s and physician’s satisfaction with the sedation. The properties of a model sedative agent for endoscopy would include rapid onset and offset of action, analgesic and anxiolytic effects, ease of titration to desired level of sedation, rapid recovery and an excellent safety profile. Therefore there is an impulse for development of new approaches to endoscopic sedation. This article provides an update on the methods of sedation today available and future directions in endoscopic sedation.

Sedation and anesthesia options for pediatric patients in the radiation oncology suite

External beam radiation therapy (XRT) has become one of the cornerstones in the management of pediatric oncology cases. While the procedure itself is painless, the anxiety it causes may necessitate the provision of sedation or anesthesia for the patient. This review paper will briefly review the XRT procedure itself so that the anesthesia provider has an understanding of what is occurring during the simulation and treatment phases. We will then examine several currently used regimens for the provision of pediatric sedation in the XRT suite as well as a discussion of when and how general anesthesia should be performed if deemed necessary. Standards of care with respect to patient monitoring will be addressed. We will conclude with a survey of the developing field of radiation-based therapy administered outside of the XRT suite.

A randomized, double-blind, phase 3 study of fospropofol disodium for sedation during colonoscopy

GOALS

This double-blind, multicenter study evaluated the safety and efficacy of intravenous fospropofol (6.5 mg/kg vs. 2 mg/kg) for moderate sedation in patients undergoing colonoscopy.

METHODS

In all, 314 patients >or=18 years (American Society of Anesthesiologists PS1 to PS3) were randomized to receive fospropofol 2 mg/kg, fospropofol 6.5- mg/kg, or midazolam 0.02 mg/kg, after pretreatment with intravenous fentanyl 50 mcg. Supplemental doses of study medication were permitted to achieve a Modified Observer's Assessment of Alertness/Sedation scale score <or=4 and to enable the investigator to begin a procedure. The study end points included sedation success, recovery, memory retention, physician satisfaction, and safety.

RESULTS

Sedation success was higher in the fospropofol 6.5 mg/kg versus 2 mg/kg group (87% vs. 26%; P<0.001) and was 69% in the midazolam group. Patients in the 6.5-mg/kg group were significantly less likely to remember being awake during the procedure (51% vs. 100% in the 2-mg/kg group, P<0.001; 60% for the midazolam group). Patients in the fospropofol groups had similar memory retention (70% and 82% for the 6.5 mg/kg and 2 mg/kg groups, respectively) compared with 41% for the midazolam group. Mean physician satisfaction scores were higher in the fospropofol 6.5-mg/kg group (7.7) than the 2-mg/kg group (4.5), P<0.001. Most adverse events were mild to moderate in intensity; the most common treatment-related adverse events were paresthesias (68% vs. 60%) and pruritus (16% vs. 26%) in the fospropofol 6.5 and 2 mg/kg groups, respectively.

CONCLUSIONS

The fospropofol 6.5-mg/kg dosing regimen was well tolerated and effective for sedation during colonoscopy and was associated with higher rates of sedation success, memory retention, and physician satisfaction than the fospropofol 2-mg/kg dose.

Monitored anesthesia care (MAC) sedation: clinical utility of fospropofol

Fospropofol, a phosphorylated prodrug version of the popular induction agent propofol, is hydrolyzed in vivo to release active propofol, formaldehyde, and phosphate. Pharmacodynamic studies show fospropofol provides clinically useful sedation and EEG/bispectral index suppression while causing significantly less respiratory depression than propofol. Pain at the injection site, a common complaint with propofol, was not reported with fospropofol; the major patient complaint was transitory perianal itching during the drug's administration. Although many clinicians believe fospropofol can safely be given by a registered nurse, the FDA mandated that fospropofol, like propofol, must be used only in the presence of a trained anesthesia provider.

Fospropofol disodium, a water-soluble prodrug of the intravenous anesthetic propofol (2,6-diisopropylphenol)

BACKGROUND

Today, propofol or 2,6-diisopropylphenol is the anesthetic mainly used for monitored anesthetic care sedation and during intravenous anesthesia. The formulation, a lipid macroemulsion, shows several disadvantages. Therefore, during the past years considerable scientific effort has been undertaken to find either a better formulation or a prodrug of propofol. Fospropofol is the first propofol prodrug that has been intensively studied in man. It has been licensed in 2008 by the FDA for monitored anesthetic care sedation.

OBJECTIVES AND METHODS

This review describes first published study results of fospropofol with regard to its pharmacokinetics/pharmacodynamics, drug safety, tolerability and drug side effects. Using a Medline search all published articles and abstracts containing the words fospropofol or GPI 15715 were included.

RESULTS AND CONCLUSION

As the impact of an errorness drug assay for propofol liberated from fospropofol is not exactly defined, no clear conclusions can be drawn from the first published pharmacokinetic/pharmacodynamic studies. Fospropofol was well tolerated in the first two clinical studies and no serious side effects were reported. After characterization of the true pharmacokinetic/pharmacodynamics profile, fospropofol, an aqueous solution, has the potential to favorably compare with benzodiazepines for procedural sedation and also may be used for long-term sedation and intravenous anesthesia.

Fospropofol: a new sedative-hypnotic agent for monitored anesthesia care

OBJECTIVE

To summarize the published clinical data on fospropofol, critically review the safety and efficacy information, and provide pertinent information for formulary review.

DATA SOURCES

Data were collected from searches of MEDLINE (1966-June 30, 2009), EMBASE (1974-June 30, 2009), bibliographies of manuscripts, and www.fda.gov. Key search terms included fospropofol, Lusedra, Aquavan, sedative-hypnotic, and monitored anesthesia care.

STUDY SELECTION AND DATA EXTRACTION

All Phase 1, Phase 2, and Phase 3 clinical trials studying the safety and efficacy of fospropofol were reviewed.

DATA SYNTHESIS

Fospropofol is a water-soluble prodrug of propofol, a potent sedative-hypnotic agent. Propofol is highly lipophilic and is formulated in lipid-containing solvents, which have known disadvantages, including pain on injection, narrow therapeutic window with the potential to cause deep sedation, high lipid intake during long-term sedation, and risk of infection resulting from bacterial contamination. Due to its water solubility, fospropofol eliminates some of the known lipid emulsion-associated disadvantages of propofol and provides a more predictable peak onset of activity and more gradual recovery to a full state of consciousness. The pharmacokinetic and pharmacodynamic profiles of fospropofol make it an attractive agent for sedation for procedures of short duration. Unfortunately, the number of patients studied has been relatively small and the amount of safety data is limited. Of concern are reports of hypoxemia and hypotension; these reports are limited in number, but the episodes are serious and may require acute intervention. Although fospropofol holds promise for procedural sedation, due to limited safety data, the Food and Drug Administration has limited approval of fospropofol to monitored anesthesia care in patients undergoing diagnostic or therapeutic procedures.

CONCLUSIONS

Fospropofol is a viable addition to the class of sedative-hypnotic agents due to the minimization of unwanted adverse effects of propofol and maintenance of a favorable pharmacokinetic profile facilitating sedation, anxiolysis, and rapid recovery. However, there are limited safety data to justify its use without the presence of dedicated anesthesia personnel.

Anesthesia for gastrointestinal endoscopic procedures

Traditionally, sedation for gastrointestinal endoscopic procedures was provided by the gastroenterologist. Increasingly, however, complex procedures are being performed on seriously ill patients. As a result, anesthesiologists now are providing anesthesia and sedation in the gastrointestinal endoscopy suite for many of these patients. This article reviews the challenges encountered in this environment and anesthetic techniques that can be used successfully for these procedures.

Advances in interventional pulmonology

PURPOSE OF REVIEW

Interventional pulmonology is a rapidly expanding field offering less invasive therapeutic procedures for significant pulmonary problems. Many of the therapies may be new for the anesthesiologist. Although less invasive than surgery, some of these procedures will carry significant risks and complications. The team approach by anesthesiologist and pulmonologist is key to the success of these procedures.

RECENT FINDINGS

Many modalities for central airway obstruction have emerged, including the expanding application of airway stenting procedures. Diagnostic bronchoscopy with ultrasound guidance promises great advances in lung cancer staging. New bronchoscopic treatments of asthma and emphysema are actively under investigation. Advances in anesthetic agents and techniques for interventional pulmonology procedures have also occurred.

SUMMARY

This review is intended to familiarize the anesthesiologist with current and rising therapeutic modalities for pulmonary disease. Knowledge of interventional pulmonology facilitates planning and preparation for well tolerated and effective procedures.

Fospropofol Disodium

Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing inservices. A comprehensive target drug utilization evaluation (DUE) is also provided each month. With a subscription, the monographs are sent in print and are also available online. Monographs can be customized to meet the needs of a facility. Subscribers to The Formulary Monograph Service also receive access to a pharmacy bulletin board, The Formulary Information Exchange (The F.I.X.). All topics pertinent to clinical and hospital pharmacy are discussed on The F.I.X.

Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service or The F.I.X., call The Formulary at 800-322-4349. The March 2009 monograph topics are plerixafor, degarelix, armodafinil, iloperidone, and lasofoxifene. The DUE is on degarelix.

Update on pharmacology of hypnotic drugs

PURPOSE OF REVIEW

This review is intended to provide an update on pharmacology of hypnotic drugs and current state of published research for new or improved agents.

RECENT FINDINGS

Albeit no completely new drugs have been launched in the last few years, research on pharmacology of existing drugs is still ongoing, and new formulations of existing drugs are proposed (propofol, isoflurane). Xenon, an old but so far unavailable drug, has elicited new interests and this review will examine the recent publications on this fascinating agent.

SUMMARY

These results will improve our handling of existing drugs and open new perspectives on drug monitoring through measurement of propofol concentrations in expired air.

Fospropofol disodium injection for the sedation of patients undergoing colonoscopy

Sedation plays a central role in making colonoscopy tolerable for patients and feasible for the endoscopist to perform. The array of agents used for endoscopic sedation continues to evolve. Fospropofol (FP), a prodrug of propofol with a slower pharmacokinetic profile, is currently under evaluation for use during endoscopic procedures. Preliminary data suggests that FP dosed at 6.5 mg/kg is well tolerated by most patients with perineal paresthesias being the most commonly experienced adverse effect. This article will examine the current literature on the use of FP for the sedation of patients undergoing colonoscopy, highlighting the pharmacokinetics, pharmacodynamics, risks, and common adverse events associated with the novel sedative/hypnotic.