Design of a new Nd:YAG Thomson scattering system for MAST.

A new infrared Thomson scattering system has been designed for the MAST tokamak. The system will measure at 120 spatial points with approximately 10 mm resolution across the plasma. Eight 30 Hz 1.6 J Nd:YAG lasers will be combined to produce a sampling rate of 240 Hz. The lasers will follow separate parallel beam paths to the MAST vessel. Scattered light will be collected at approximately f/6 over scattering angles ranging from 80 degrees to 120 degrees. The laser energy and lens size, relative to an existing 1.2 J f/12 system, greatly increases the number of scattered photons collected per unit length of laser beam. This is the third generation of this polychromator to be built and a number of modifications have been made to facilitate mass production and to improve performance. Detected scattered signals will be digitized at a rate of 1 GS/s by 8 bit analog to digital converters (ADCs.) Data may be read out from the ADCs between laser pulses to allow for real-time analysis.

A randomized, double-blind, crossover comparison of the efficacy and safety of oral controlled-release tramadol and placebo in patients with painful osteoarthritis.

OBJECTIVE: To compare the efficacy and safety of controlled-release (CR) tramadol (Zytram XL, Purdue Pharma, Canada) and placebo in patients with painful osteoarthritis. METHODS: Patients underwent analgesic washout for two to seven days before random assignment to 150 mg daily of CR tramadol or placebo, and were titrated weekly to 200 mg, 300 mg or a maximum of 400 mg once daily. After four weeks, patients crossed over to the alternate treatment for another four weeks. Plain acetaminophen was provided as a rescue analgesic. All patients who completed the crossover study were eligible to receive open label CR tramadol for six months. RESULTS: Seventy-seven of 100 randomly assigned patients were evaluable for efficacy. CR tramadol resulted in significantly lower visual analogue scale pain intensity scores (37.4+/-23.9 versus 45.1+/-24.3, P=0.0009). Western Ontario and McMaster Universities osteoarthritis index subscale scores for pain (189.0+/-105.0 versus 230.0+/-115.4; P=0.0001) and physical function (632.4+/-361.3 versus 727.4+/-383.4; P=0.0205) were significantly better with CR tramadol. Total pain and disability (22.8+/-14.5 versus 27.2+/-14.8; P=0.0004), and overall pain and sleep (104.7+/-98.0 versus 141.0+/-108.2; P=0.0005) scores in the Pain and Sleep Questionnaire were significantly lower for CR tramadol. Short-form 36 Health Survey scores were significantly better during CR tramadol treatment for the pain index (38.8+/-10.8 versus 35.6+/-9.0; P=0.0100), general health perception (46.5+/-11.2 versus 44.4+/-11.6; P=0.0262), vitality (43.1+/-13.2 versus 40.2+/-13.7; P=0.0255) and overall physical components (40.8+/-8.9 versus 37.8+/-7.7; P=0.0002). CR tramadol treatment was preferred by 55.8% of patients (P=0.0005) versus 20.8% and 23.4% of patients who chose placebo or had no preference, respectively. These improvements were sustained for up to six months, and 86.5% of patients reported at least moderate benefit from CR tramadol during long-term treatment. CONCLUSION: CR tramadol is effective for the management of painful osteoarthritis.

Once-daily, controlled-release tramadol and sustained-release diclofenac relieve chronic pain due to osteoarthritis: a randomized controlled trial.

OBJECTIVE: The present study was a randomized, parallel, double-blind comparison between controlled-release (CR) tramadol and sustained-release (SR) diclofenac in patients with chronic pain due to osteoarthritis of the hips and/or knees. METHODS: Patients with at least moderate pain intensity, and having received analgesics over the past three months, underwent a two- to seven-day washout of current analgesics before initiation of 200 mg CR tramadol or 75 mg SR diclofenac. During the eight-week study, patients returned to the clinic biweekly. CR tramadol doses were titrated to a maximum of 200 mg, 300 mg or 400 mg per day. SR diclofenac doses were titrated to 75 mg or 100 mg once daily, or 75 mg twice a day based on pain relief and the presence of side effects. For rescue analgesic, patients took acetaminophen as needed, up to 650 mg three times a day. RESULTS: Forty-five patients on CR tramadol and 52 patients on SR diclofenac were evaluable. Significant improvements from prestudy treatment were shown for visual analogue scale pain (P=0.0001), stiffness (P<0.0005) and physical function (P=0.0001) scores for both treatments. There were no significant differences between the two treatments in the Western Ontario and McMaster Universities subscales, overall pain, pain and sleep, or the clinical effectiveness evaluation. Overall incidence of adverse events was similar in both groups, with more opioid-related adverse events with CR tramadol, and two serious adverse events occurring with the use of SR diclofenac. CONCLUSIONS: CR tramadol is as effective as SR diclofenac in the treatment of pain due to knee or hip osteoarthritis, with the potential for fewer of the serious side effects that characterize nonsteroidal anti-inflammatory drug administration.

Double blind randomized placebo control trial of controlled release codeine in the treatment of osteoarthritis of the hip or knee.

OBJECTIVE: Pain is the cardinal feature of osteoarthritis (OA), and with advancing disease there is loss of function and increasing pain even at times of joint rest. Few studies have evaluated the role of opioid analgesics in treating the pain of OA. METHODS: This randomized, double blind, parallel group study compared the efficacy and safety of a 12 hourly controlled release codeine formulation (Codeine Contin) with placebo in patients with chronic pain due to OA of the hips and/or knees. The 4 week treatment period, following an analgesic washout phase of 2-7 days, included weekly clinic evaluations, at which the dose was escalated as appropriate, and daily patient diary completion. Pain (daily), stiffness, and physical function (weekly) were assessed using the multidimensional, self-administered WOMAC (visual analog scale version) questionnaire. RESULTS: Sixty-six eligible patients completed the study. The mean initial and final daily doses of controlled release codeine were 50 mg every 12 h at baseline and 159 mg every 12 h at the final assessment. All variables in the efficacy analysis indicated superiority of controlled release codeine over placebo. The WOMAC pain scale showed an improvement of 44.8% over baseline in the controlled release codeine group compared with 12.3% taking placebo (p = 0.0004). For the WOMAC stiffness and physical function scales the improvements over baseline on controlled release codeine were 47.7% and 49.3%, respectively compared with 17.0% and 17.0%, respectively, with placebo (p = 0.003; p = 0.0007). Controlled release codeine was also significantly better than placebo on measures of sleep quality and requirement for supplemental acetaminophen. CONCLUSION: Single entity controlled release codeine is an effective treatment for pain due to OA of the hip or knee.

Sleep quality and nocturnal respiratory function with once-daily theophylline (Uniphyl) and inhaled salbutamol in patients with COPD.

We compared the effects of evening administration of sustained-release theophylline (Uniphyl) and qid inhaled beta 2-agonist (salbutamol, two 100-micrograms puffs) on sleep quality and nocturnal oxygen saturation in 20 patients with COPD. Patients with FEV1 less than 70% predicted and FEV1/FVC ratio less than 70% were eligible to participate in this double-blind, crossover study, with 2-week treatment arms. Patients recorded morning and evening peak flow and symptoms in a daily diary. On the last day of each treatment period, overnight polysomnography was done. Spirometric indexes were measured before retiring and on awakening. Patients spent less time at less than 90% oxygen saturation (51 +/- 92 min vs 72 +/- 105 min; p = 0.03) during theophylline treatments than during salbutamol treatment. There was a smaller overnight decrease in FEV1 (0.04 L vs 0.13 L; p = 0.04) after theophylline than after sallbutamol treatment. FEV1/FVC ratio and maximum expiratory flow at 50% of vital capacity (V50) increased overnight with theophylline and decreased with salbutamol (p = 0.014, 0.025). Morning peak expiratory flow rate was higher with theophylline (4.0 +/- 1.7 L/s) than with salbutamol (3.6 +/- 1.8 L/s; p = 0.004). The duration of patient-reported nocturnal wheezing was lower with theophylline than with salbutamol (p = 0.006). There were no differences between treatments in sleep quantity, efficiency, staging, or subjective quality. We conclude that, compared with salbutamol, evening administration of once-daily theophylline results in better nocturnal oxygen saturation and an improvement in the overnight change in pulmonary function, without affecting sleep architecture, in patients with COPD.

Randomized evaluation of controlled-release codeine and placebo in chronic cancer pain.

Codeine is widely used in combination with acetaminophen and aspirin for the management of mild to moderate pain. However, there are few controlled clinical trials of single-entity codeine in chronic cancer pain. The purpose of this study was to evaluate the clinical efficacy and safety of controlled-release codeine given every 12 hr in patients with cancer pain. Thirty-five patients with chronic cancer pain were randomized in a double-blind crossover study to controlled-release (CR) codeine or placebo, for 7 days each. Pain intensity was assessed at 0800 hr and 2000 hr using a visual analogue scale (VAS) and a five-point categorical scale, and the use of "rescue" acetaminophen-plus-codeine (300 mg/30 mg every 4 hr as needed) was recorded. Thirty patients completed the study (17 male, 13 female; mean age, 64.4 +/- 9.8 years) with a mean daily CR codeine dose of 277 +/- 77 mg (range, 200-400 mg). CR codeine treatment resulted in significantly lower overall VAS pain intensity scores (22 +/- 18 mm versus 36 +/- 20 mm, P = 0.0001), categorical pain intensity scores (1.2 +/- 0.8 versus 1.8 +/- 0.8, P = 0.0001), and pain scores when assessed by day of treatment and by time of day. Daily "rescue" analgesic consumption was significantly lower on CR codeine, compared to placebo treatment (2.2 +/- 2.3 versus 4.6 +/- 2.8 tablets per day, P = 0.0001). Both patients and investigators preferred CR codeine to placebo (80% versus 3%, P = 0.0014 and 73% versus 7%, P = 0.0160, respectively). These data indicate that CR codeine, given every 12 hr results in significant reductions in pain intensity and the use of "rescue" acetaminophen-plus-codeine in patients with cancer pain. CR codeine provides the benefits of a flexible single entity codeine formulation and the convenience of 12-hr duration of action, which allows patients uninterrupted sleep and improved compliance.

Steady-state pharmacokinetic evaluation of a novel, controlled-release morphine suppository and subcutaneous morphine in cancer pain.

Although the oral route is the preferred method for morphine administration for cancer pain, many patients will require an alternate route of administration at some point during their illness. The authors studied the steady-state pharmacokinetics of morphine after administration of a novel, controlled-release suppository (MS-CRS) and subcutaneous morphine in a randomized, double-blind, two-way crossover evaluation in 10 patients with cancer pain. When administered at a 2.5:1 analgesic ratio, MS-CRS given every 12 hours showed an equivalent extent of absorption compared with subcutaneous morphine given every 4 hours (AUC0-12, 132.5 +/- 30.1 versus 123.8 +/- 27.3 ng.h.mL-1, P = not significant [NS]). Peak morphine concentrations were lower, time of peak was later, and percent fluctuation less after MS-CRS than after subcutaneous morphine (Cmax, 14.7 +/- 2.9 versus 29.9 +/- 5.4 ng/mL, P = .0110; tmax, 3.33 +/- 0.75 versus 2.22 +/- 0.15 hours, P = .0160; fluctuation, 122 +/- 71 versus 356 +/- 123%, P = .00160). Relative bioavailability of MS-CRS using the 2.5:1 analgesic ratio was 105%, and bioavailability from data dose normalized without regard to route specificity in metabolism was 42%. For both routes of administration there was a significant linear relationship between morphine dose and AUC (MS-CRS, r = .8568, P = .0032; subcutaneous morphine, r = .8314, P = .0055). MS-CRS morphine provides a pharmacokinetic profile consistent with dosing every 12 hours; at steady state, the extent of absorption is comparable with that of subcutaneous morphine when administered at a 2.5:1 dose ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical efficacy and safety of a novel controlled-release morphine suppository and subcutaneous morphine in cancer pain: a randomized evaluation.

PURPOSE: A significant number of cancer patients will require an alternate route of morphine administration at some point during their illness. This study compared the clinical efficacy and safety of a novel morphine sulfate controlled-release suppository (MS-CRS) and subcutaneous (SC) morphine in patients with cancer pain. METHODS: Thirty patients with cancer pain were randomized in a double-blind crossover study to MS-CRS every 12 hours or SC morphine every 4 hours for 4 days each, using a 2.5:1 analgesic equivalence ratio. Pain intensity was assessed using a visual analog scale (VAS) and the Present Pain Intensity Index of the McGill Pain Questionnaire. Nausea and sedation were also assessed with a VAS. Evaluations were made by the patient at 8 AM, noon, 4 PM, and 8 PM and rescue morphine consumption recorded. RESULTS: Twenty-three patients completed the study (13 men and 10 women; mean age, 64.0 +/- 2.0 years) and were treated with mean daily MS-CRS and SC morphine doses of 326 +/- 69 mg and 138 +/- 28 mg, respectively. There was a small but significant difference in overall ordinal pain-intensity scores in favor of MS-CRS (0.7 +/- 0.1 v 0.9 +/- 0.1, P = .0459). There were no significant differences between MS-CRS and SC morphine in overall VAS scores for pain intensity (13 +/- 3 v 13 +/- 3 mm), sedation (23 +/- 3 v 25 +/- 4 mm), and nausea (8 +/- 2 v 9 +/- 2 mm). The mean daily rescue analgesic consumption during MS-CRS and SC morphine did not differ significantly (1.2 +/- 0.4 v 1.2 +/- 0.4 doses/d). CONCLUSION: MS-CRS, administered every 12 hours, provides analgesia comparable to SC morphine and represents a reliable, noninvasive alternative method of pain control for patients unable to take oral morphine.

Efficacy of Uniphyl, salbutamol, and their combination in asthmatic patients on high-dose inhaled steroids.

A group of 32 patients with moderately severe, chronic asthma (mean FEV1 55% of predicted), maintained on moderately high doses of inhaled corticosteroids (mean dose 1,100 micrograms/d), participated in this double-blind, placebo-controlled crossover study. The effect on pulmonary function of adding theophylline (U, once daily Uniphyl), inhaled salbutamol (S, 200 micrograms four times per day), and their combination (C) or placebo (P) was assessed on Day 14 of each treatment phase. Patients recorded peak expiratory flow, asthma symptom severity (morning and evening), and use of rescue salbutamol inhaler in daily diaries. Mean FEV1 between 0730 and 1800 h and maximum FEV1 between 0730 and 1300 h were significantly higher on U, S, and C compared with P (p < 0.006). Morning peak flow and FEV1 (0730 h) were significantly higher on U and C compared with S and P (p < 0.01). Evening peak flow was higher on U than P (p < 0.001), and C was higher than S and P (p < 0.01). Rescue salbutamol inhaler use was significantly higher on P than on U, C, or S (p = 0.0001). Patient rating of asthma symptoms during C was significantly better than on S or P (p < 0.05). Patient rating of asthma control and study phase preference was significantly higher on combination and Uniphyl alone than on placebo, the combination also being superior to salbutamol alone. Addition of Uniphyl or a combination of Uniphyl and salbutamol significantly improves pulmonary function and asthma symptoms in patients treated with high doses of inhaled corticosteroids and as-needed beta agonists.(ABSTRACT TRUNCATED AT 250 WORDS)

Steady-state pharmacokinetics of hydromorphone and hydromorphone-3-glucuronide in cancer patients after immediate and controlled-release hydromorphone.

Although the pharmacokinetics of oral hydromorphone has been evaluated in healthy volunteers after small single oral doses, data are not available regarding the disposition of hydromorphone and its principal metabolite, hydromorphone-3-glucuronide (H3G), at steady-state and after large oral doses. The authors studied the pharmacokinetics of hydromorphone and H3G after oral administration of an immediate-release (IR) and controlled-release (CR) formulation of hydromorphone at a daily dose of 48 +/- 11 mg (range 6-216 mg) in a randomized, double-blind, steady-state, two-way crossover evaluation in 18 patients with chronic cancer pain. Controlled-release hydromorphone demonstrated equivalent bioavailability and acceptable CR characteristics, when compared with IR hydromorphone (CR vs. IR: AUC0-12 123.10 +/- 20.38 vs. 118.98 +/- 20.92 ng.hr.mL-1, P = NS, Cmax 17.76 +/- 3.07 vs. 19.70 +/- 4.04 ng.mL-1, P = NS, Cmin 6.04 +/- 1.01 vs. 5.28 +/- 1.000 ng.mL-1, P = NS, and Tmax 4.78 +/- 0.78 vs. 1.47 +/- 0.22 hr, P = 0.0008). A significant linear relationship existed between hydromorphone dose and hydromorphone AUC (r = 0.8315, P = 0.0001) and between hydromorphone AUC and H3G AUC (r = 0.8048, P = 0.0001) over a wide dose range. The steady-state molar ratio of H3G to hydromorphone was 27:1. The authors conclude that CR hydromorphone provides a pharmacokinetic profile consistent with 12 hourly dosing and that at steady state, oral hydromorphone is extensively metabolized to H3G, although the pharmacologic activity of this metabolite remains unknown.

Comparison of the efficacy, safety, and pharmacokinetics of controlled release and immediate release metoclopramide for the management of chronic nausea in patients with advanced cancer.

BACKGROUND: The short elimination half-life of metoclopramide necessitates frequent administration for optimal relief of nausea. This study compares a newly developed controlled release preparation of metoclopramide (CRM) and immediate release metoclopramide (IRM) with respect to efficacy, safety, and pharmacokinetics in patients with chronic nausea associated with advanced cancer. METHODS: Thirty-four patients with advanced cancer with nausea lasting more than 1 month and with no evidence of involvement of the gastrointestinal tract, peptic ulcer or gastritis, brain metastases, or metabolic abnormalities were randomized, in a double-blind cross-over study, to receive 40 mg of CRM every 12 hours or 20 mg of IRM every 6 hours for 3 days. Nausea, food intake, and side effects were assessed four times daily. On Day 3, sequential venous samples were taken (12 patients) to determine plasma metoclopramide concentrations. RESULTS: In 29 evaluable patients, the intensity of nausea on Day 3, measured by a 0-100-mm visual analogue scale and 0-3 categoric scale was 15 +/- 17 and 0.6 +/- 0.6 after IRM, versus 8 +/- 9 (P = 0.033) and 0.4 +/- 0.5 (P = 0.055) after CRM, respectively. Visual analogue scale nausea scores recorded by time of day and by day for the 3 treatment days were significantly lower for patients who received CRM compared with those who received IRM (P = 0.047 and P = 0.043, respectively), but categoric nausea scores were not significantly different between treatments by time of day and by day across the 3 treatment days. No differences were observed in caloric intake or side effects between treatments. In a pharmacokinetic analysis, the CRM/IRM ratio for area under the curve0-12 (microgram x hours x L-1), Cmax (microgram/L), and Tmax (hours) was 100%, 98%, and 2.3 fold, respectively. CONCLUSION: Controlled release metoclopramide is safe and effective in managing chronic nausea in patients with advanced cancer. Future studies should focus on characterizing this syndrome more clearly and on determining the optimal dose of metoclopramide and the effects of drug combinations that have proven to be useful in managing chemotherapy-induced emesis (i.e., metoclopramide plus corticosteroids).

Comparative clinical efficacy and safety of immediate release and controlled release hydromorphone for chronic severe cancer pain.

BACKGROUND: The short elimination half-life of hydromorphone necessitates 4-hourly dosing to maintain optimal levels of analgesia in patients with chronic cancer pain. The purpose of this study was to compare the clinical efficacy and safety of controlled release hydromorphone administered every 12 hours and immediate release hydromorphone administered every 4 hours in patients with chronic severe cancer pain. METHODS: Forty-eight patients with stable chronic severe cancer pain were randomized, in a double-masked crossover study, to controlled release hydromorphone every 12 hours or immediate release hydromorphone every 4 hours for 7 days each. Pain intensity was assessed using a visual analog scale (VAS) and the Present Pain Intensity Index of the McGill Pain Questionnaire. Nausea and sedation were also assessed using a VAS. Assessments were made by the patient four times a day at 7:00 a.m., 11:00 a.m., 3:00 p.m., and 7:00 p.m. Use of rescue hydromorphone also was recorded by the patient. RESULTS: Forty-five patients completed the study (26 women, 19 men; mean age, 57.1 +/- 13.6 years) and received a mean daily dose of 76 +/- 133 mg (range, 6-768 mg). There were no significant differences between controlled release hydromorphone and immediate release hydromorphone in overall VAS pain intensity scores (19 +/- 14 vs. 20 +/- 14 mm), ordinal pain intensity scores (1.2 +/- 0.8 vs. 1.2 +/- 0.8) and pain scores by day of treatment or time of day. The daily rescue analgesic consumption during controlled release hydromorphone and immediate release hydromorphone did not differ significantly overall (1.1 +/- 1.1 vs. 1.0 +/- 1.1 doses per day) or with respect to time of day. There were no significant differences in overall VAS sedation scores (18 +/- 18 mm vs. 19 +/- 18 mm) and in overall mean VAS nausea scores (12 +/- 15 mm vs. 11 +/- 14 mm) between controlled release hydromorphone and immediate release hydromorphone. CONCLUSIONS: Controlled release hydromorphone administered every 12 hours is as effective as immediate release hydromorphone administered every 4 hours in the management of patients with chronic severe cancer pain. The benefits of controlled release hydromorphone lie in the convenience of its capsule formulation, which can be sprinkled on soft food, and its 12-hour duration of action, which allows patients uninterrupted sleep and improved compliance.

The dose-response relationship of controlled-release codeine (Codeine Contin) in chronic cancer pain.

The improved pain control provided by regular dosing of opioid analgesics in patients with severe cancer pain has been well established. However, the treatment of mild-to-moderate cancer pain is often limited to "as needed" dosing with fixed combinations of codeine or oxycodone plus a nonopioid analgesic, which do not allow optimal titration of the individual components. This randomized double-blind study was designed to evaluate the efficacy of controlled-release codeine (Codeine Contin) in patients with cancer pain, and to estimate its dose equivalence to a standard combination of acetaminophen plus codeine. Twenty-four patients with at least moderate cancer pain were randomized to Codeine Contin 100, 200, or 300 mg every 12 hr or acetaminophen plus codeine (600 mg/60 mg) every 6 hr. On days 1 and 4 of dosing, pain intensity and pain relief were assessed hourly for 12 hr. The sum of pain intensity differences (SPID) from baseline and the total pain relief (TOTPAR) scores demonstrated a dose-response relationship for Codeine Contin on days 1 and 4 that was statistically significant on day 1 and suggested greater analgesic efficacy on day 4, compared with day 1. Codeine Contin 150 mg every 12 hr was estimated to be equianalgesic to acetaminophen plus codeine (600 mg/60 mg) given every 6 hr. Because a similar equivalence was also demonstrated from analysis of adverse event data, it is concluded that Codeine Contin 150 mg produces analgesia and a side-effect profile similar to a 40% lower dose of codeine provided by the combination.(ABSTRACT TRUNCATED AT 250 WORDS)

Disposition of morphine and its glucuronide metabolites after oral and rectal administration: evidence of route specificity.

Morphine-6-glucuronide is a metabolite of morphine that shows significant analgesic effects in animals and humans. To evaluate route-specific differences in the potential contribution of morphine-6-glucuronide to morphine analgesia, we studied the pharmacokinetics of morphine, morphine-6-glucuronide, and morphine-3-glucuronide after oral and rectal administration of morphine sulfate in a six-subject randomized, single-dose, two-way crossover evaluation. The mean area under the plasma concentration-time curve (AUC) molar ratios of morphine-6-glucuronide (M6G) and morphine-3-glucuronide (M3G) to morphine (M) were greater after oral morphine administration compared with rectal morphine administration (M6G/M ratio, 2.7:1 versus 1.3:1, p = 0.025; M3G/M ratio, 18.3:1 versus 9.3:1, p = 0.002). Systemic bioavailability and peak plasma concentrations of morphine-6-glucuronide and morphine-3-glucuronide were significantly greater after oral morphine administration compared with the rectal route (AUC: M6G, 377.1 +/- 124.2 versus 236.2 +/- 133.7 nmol.hr/L, p = 0.05; M3G, 2610.1 +/- 446.4 versus 1650.2 +/- 309.0 nmol.hr/L, p = 0.004; maximum concentrations: M6G, 110.9 +/- 37.5 versus 64.6 +/- 28.8 nmol/L, p = 0.002; M3G, 576.9 +/- 155.8 versus 266.8 +/- 110.5 nmol/L, p = 0.007). Conversely, the systemic availability of morphine was lower after oral administration, although this difference failed to achieve statistical significance (142.3 +/- 17.1 versus 176.6 +/- 69.4 nmol.hr/L, p = 0.14). These data suggest that rectal administration of morphine is associated with significant avoidance of hepatic biotransformation, and they provide a convincing argument for the evaluation of morphine-6-glucuronide concentrations in pharmacokinetic and pharmacodynamic comparisons involving different routes of morphine administration.

Using memory for pain in analgesic research.

OBJECTIVE: To determine the validity of pain intensity recall at 24 and 48 hours as a substitute for hourly pain assessments in repeated-dose analgesic studies. SETTING: Orthopedic unit of an acute care teaching hospital. PARTICIPANTS: Eighty-four patients undergoing arthroscopic reconstruction of the anterior cruciate ligament, using the patellar tendon, who were participating in a randomized, double-blind, parallel-group analgesic study. INTERVENTIONS: Patients rated their pain intensity every hour (while awake) for 48 hours and their recall of worst, least, and usual pain intensity at 24 and 48 hours using a visual analog scale (VAS). MAIN OUTCOME MEASURES: This study examined the relationship between recall of worst, least, and usual pain intensity at 24 and 48 hours and the experienced maximum, minimum, and mean pain intensity VAS scores obtained from hourly assessments over the 0-24- and 0-48-hour periods, respectively. The significance of differences between recalled and experienced pain intensity variables was assessed. RESULTS: Worst, least, and usual pain recall at 24 and 48 hours were highly correlated with experienced maximum, minimum, and mean pain from hourly reports, respectively, over the 0-24- and 0-48-hour periods (Pearson correlation coefficients, r = 0.80-0.89, p < 0.0001). Among the three pain recall variables, usual pain showed the highest correlation with hourly measurements. There were no significant differences between recalled pain and the corresponding measures of pain from the hourly VAS scores, except in the case of 48-hour recall of worst pain (Student's t-test, p = 0.001). CONCLUSIONS: The close agreement between actual pain experience and recall of pain provides support for the use of pain recall in assessing analgesic efficacy in clinical trials.

Evaluation and use of opioid analgesics in pediatric cancer pain.

Morphine is the preferred opioid analgesic in pediatric cancer pain due to extensive clinical experience with it, significant pharmacokinetic and pharmacodynamic data following oral and parenteral administration, global availability, and the development of controlled-release formulations. Randomized clinical trials are needed to fully evaluate the pharmacokinetics, dose equivalence, clinical efficacy, and safety of other opioid analgesics in cancer pain. Clinical trials are also needed to evaluate the efficacy and safety of adjuvant analgesics in children, including tricyclic antidepressants, anticonvulsants, and antiarrhythmics for neuropathic pain and corticosteroids and diphosphonates for bone pain. Unfortunately, the number of children with cancer pain and stable analgesic requirements is usually not large enough to support well-controlled clinical trials at a single institution. Consequently, multicentre and perhaps multinational efforts are necessary to fully evaluate opioid pharmacokinetics, pharmacodynamics, and dosage guidelines in children with cancer.

Pharmacokinetics of two novel rectal controlled-release morphine formulations.

Administration of morphine by the oral route is not possible in cancer patients who are unable to swallow or are intolerant of oral morphine. Thus, there is a need for reliable alternate routes of drug administration. We compared the bioavailability of two prototype 30-mg morphine sulfate controlled-release suppository formulations (high and low viscosity) with 30-mg oral controlled-release morphine sulfate tablets in a 14-subject single-dose randomized, three-way crossover study. Venous blood samples were obtained immediately prior to and for 24 hr following each dose. Morphine concentrations were determined by radioimmunoassay. Compared with oral controlled-release morphine, the high- and low-viscosity suppository formulations had significantly greater bioavailability (AUC0-24 72.7 +/- 13.2 for the oral preparation versus 98.6 +/- 35.7 and 105.8 +/- 37.3 ng.hr/mL for the suppositories, respectively, P < 0.05), later peak concentration (tmax 2.3 +/- 0.8 versus 3.1 +/- 2.3 and 5.0 +/- 1.5 hr, respectively, P < 0.05), and longer half-value duration (4.3 +/- 1.6 versus 10.4 +/- 5.5 and 9.5 +/- 4.3 hr, respectively, P < 0.05). Peak concentration for the high-viscosity suppository formulation (Cmax 7.75 +/- 2.66 ng/mL) was significantly lower than the low-viscosity suppository (Cmax 9.23 +/- 2.85 ng/mL) and the oral tablet (Cmax 10.4 +/- 2.78 ng/mL) formulations (P < 0.05). The increased bioavailability observed with the two controlled-release suppositories may be the result of partial avoidance of hepatic biotransformation with rectal administration.