Biomedical subjects

Lynn R Webster

Publications and source records attributed to Lynn R Webster.

5 recordsLinked to original sources

PubMed2006

Oxytrex minimizes physical dependence while providing effective analgesia: a randomized controlled trial in low back pain.

UNLABELLED: Physical dependence or withdrawal is an expected effect of prolonged opioid therapy. Oxytrex (oxycodone + ultralow-dose naltrexone) is an investigational drug shown here to minimize physical dependence while providing strong analgesia with twice-daily dosing. In this 719-patient, double-blind, placebo- and active-controlled Phase III clinical trial in chronic low back pain, patients were randomized to receive placebo, oxycodone qid, or oxytrex qid or bid. Each oxytrex tablet contains 1 microg naltrexone; oxytrex bid and qid treatments provide 2 and 4 microg naltrexone/day, respectively. Following a washout, patients with pain >or=5 on a 0-10 scale were dose-escalated weekly from 10 up to 80 mg/day until reaching adequate pain relief (<or=2) or a tolerable level of side effects. Following titration, the dose was fixed for 12 weeks. Active treatment groups attained comparable analgesia despite significantly lower drug use (P = .03) by oxytrex patients. Patients taking oxytrex bid reported 55% less physical dependence than patients on oxycodone (P = .01) by the Short Opiate Withdrawal Scale 24 h after treatment cessation. Oxytrex bid patients also reported decreased moderate-to-severe constipation (by 44%, P = .01), somnolence (by 33%, P = .03), and pruritus (by 51%, P < .001). This is the first large well controlled study to show strong analgesia with minimal withdrawal symptoms and better safety compared with oxycodone. PERSPECTIVE: Previous clinical data have shown ultralow-dose naltrexone enhances and prolongs oxycodone analgesia, and preclinical data also show a suppression of opioid tolerance and dependence. A cellular mechanism of action has been demonstrated to be the prevention of aberrant G protein signaling by mu opioid receptors caused by chronic opioid administration.

Adolescent↗

PubMed2006

A randomized, double-blind, placebo-controlled study of intrathecal ziconotide in adults with severe chronic pain.

Safety and efficacy data from a study of slow intrathecal (IT) ziconotide titration for the management of severe chronic pain are presented. Patients randomized to ziconotide (n = 112) or placebo (n = 108) started IT infusion at 0.1 microg/hour (2.4 microg/day), increasing gradually (0.05-0.1 microg/hour increments) over 3 weeks. The ziconotide mean dose at termination was 0.29 microg/hour (6.96 microg/day). Patients' baseline Visual Analogue Scale of Pain Intensity (VASPI) score was 80.7 (SD 15). Statistical significance was noted for VASPI mean percentage improvement, baseline to Week 3 (ziconotide [14.7%] vs. placebo [7.2%; P = 0.036]) and many of the secondary efficacy outcomes measures. Significant adverse events (AEs) reported in the ziconotide group were dizziness, confusion, ataxia, abnormal gait, and memory impairment. Discontinuation rates for AEs and serious AEs were comparable for both groups. Slow titration of ziconotide, a nonopioid analgesic, to a low maximum dose resulted in significant improvement in pain and was better tolerated than in two previous controlled trials that used a faster titration to a higher mean dose.

Adult↗

PubMed2006

Fentanyl buccal tablets.

Fentanyl buccal tablets (FBT) are designed to manage the breakthrough pain associated with chronic pain with an enhanced rate and extent of fentanyl absorption through the buccal mucosa. The formulation incorporates an effervescent reaction to produce large shifts in pH that enhance absorption. Results from studies of safety and tolerability have shown FBT to be effective and well tolerated in opioid-tolerant chronic pain patients. Adverse events were similar to those seen with other opioids and included nausea and somnolence. Adverse events were common but mild or moderate in most cases and did not cause a high drop-out rate. In addition to the treatment of breakthrough pain, FBT could be clinically efficacious for the treatment of brief, anticipated painful events. The abuse liability of FBT is unknown and caution should be used in prescribing FBT to patients with histories of substance abuse.

Administration, Oral↗

PubMedDate not supplied

Safety and efficacy of prolonged outpatient ketamine infusions for neuropathic pain.

Ketamine has demonstrated usefulness as an analgesic to treat nonresponsive neuropathic pain; however, it is not widely administered to outpatients due to fear of such side effects as hallucinations and other cognitive disturbances. This retrospective chart review is the first research to study the safety and efficacy of prolonged low-dose, continuous intravenous (IV) or subcutaneous ketamine infusions in noncancer outpatients. Thirteen outpatients with neuropathic pain were administered low-dose IV or subcutaneous ketamine infusions for up to 8 weeks under close supervision by home health care personnel. Using the 10-point verbal analog score (VAS), 11 of 13 patients (85%) reported a decrease in pain from the start of infusion treatment to the end. Side effects were minimal and not severe enough to deter treatment. Prolonged analgesic doses of ketamine infusions were safe for the small sample studied. The results demonstrate that ketamine may provide a reasonable alternative treatment for nonresponsive neuropathic pain in ambulatory outpatients.

Adolescent↗

PubMedDate not supplied

Predicting aberrant behaviors in opioid-treated patients: preliminary validation of the Opioid Risk Tool.

OBJECTIVE: To provide clinicians with a brief screening tool to predict accurately which individuals may develop aberrant behaviors when prescribed opioids for chronic pain. DESIGN: One hundred and eighty-five consecutive new patients treated in one pain clinic took the self-administered Opioid Risk Tool (ORT). The ORT measured the following risk factors associated in scientific literature with substance abuse: personal and family history of substance abuse; age; history of preadolescent sexual abuse; and certain psychological diseases. Patients received scores of 0-3 (low risk), 4-7 (moderate risk), or >or= 8 (high risk), indicating the probability of their displaying opioid-related aberrant behaviors. All patients were monitored for aberrant behaviors for 12 months after their initial visits. RESULTS: For those patients with a risk category of low, 17 out of 18 (94.4%) did not display an aberrant behavior. For those patients with a risk category of high, 40 out of 44 (90.9%) did display an aberrant behavior. The authors used the c statistic to validate the ORT, because it simultaneously assesses sensitivity and specificity. The ORT displayed excellent discrimination for both the male (c = 0.82) and the female (c = 0.85) prognostic models. CONCLUSION: In a preliminary study, among patients prescribed opioids for chronic pain, the ORT exhibited a high degree of sensitivity and specificity for determining which individuals are at risk for opioid-related, aberrant behaviors. Further studies in a variety of pain and nonpain settings are needed to determine the ORT's universal applicability.

Adolescent↗