A bioassay computer program for analgesic clinical trials

A prospective randomized trial comparing subatmospheric wound therapy with a sealed gauze dressing and the standard vacuum-assisted closure device

OBJECTIVE

Two methods of subatmospheric pressure wound therapy--wall suction applied to a sealed gauze dressing (GSUC) and the vacuum-assisted closure device (VAC)--were compared in hospitalized patients at University of Chicago Medical Center.

SUMMARY OF BACKGROUND DATA

VAC therapy is widely used, but can be expensive and difficult to apply; it also fails in some patients.

METHODS

A randomized prospective study of 87 patients (N = 45 in the GSUC arm and N = 42 in the VAC arm) was undertaken between October 2006 and May 2008. The study comprised patients with acute wounds resulting from trauma, dehiscence, or surgery.

RESULTS

Demographics and wound characteristics were similar in both groups. There were significant reductions in wound surface area and volume in each group. In the GSUC group, the reductions in wound surface area and volume were 4.5%/day and 8.4%/day, respectively (P < 0.001 for both), and in the VAC group, this was 4.9%/day and 9.8%/day, respectively (P < 0.001 for both). The reductions in wound surface area and volume were similar in both groups (P = 0.60 and 0.19, respectively, for the group-by-time interaction). The estimated difference (VAC - GSUC) was 0.4% (95% confidence interval: -1.0, 1.7) for wound surface area and 1.4% (95% confidence interval: -0.7, 3.5) for volume. The mean cost per day for GSUC therapy was $4.22 versus $96.51 for VAC therapy (P < 0.01) and the average time required for a GSUC dressing change was 19 minutes versus 31 minutes for a VAC dressing change (P < 0.01). The sum of pain intensity differences was 0.50 in the GSUC group compared with 1.73 for the VAC group (P = 0.02).

CONCLUSIONS

GSUC is noninferior to VAC with respect to changes in wound volume and surface area in an acute care setting. In addition, GSUC dressings were easier to apply, less expensive, and less painful.

Analgesic efficacy and tolerability of ketoprofen lysine salt vs paracetamol in common paediatric surgery. A randomized, single-blind, parallel, multicentre trial

BACKGROUND

In this study, we compared the analgesic efficacy of ketoprofen lysine salt (OKi) suppositories) vs paracetamol, in children undergoing minor surgery. We also studied the side-effects of the treatment.

METHODS

Eighty-five children of both sexes, aged 6-14 years, were enrolled in a multicentre, randomized, single-blind, parallel-group study design. In all patients postsurgical pain was evaluated by visual analogue scale (VAS) and degree of distress (night-time awakening, crying, behaviour and defence posture).

RESULTS

Ketoprofen lysine was more effective than paracetamol in reducing postoperative pain (P = 0.008) with earlier onset and longer duration (8 h) of the antinociceptive effect. Evaluation of area under the curve, an aggregated measure of VAS, and of distress, confirm the time profile of pain reduction. No adverse effects related to the treatment were observed.

CONCLUSIONS

Ketoprofen lysine salt can be considered a potent therapeutic approach to control postsurgery pain in children, and an alternative to other established drug regimens.

A benefit-risk assessment of caffeine as an analgesic adjuvant

Caffeine has been an additive in analgesics for many years. However, the analgesic adjuvant effects of caffeine have not been seriously investigated since a pooled analysis conducted in 1984 showed that caffeine reduces the amount of paracetamol (acetaminophen) necessary for the same effect by approximately 40%. In vitro and in vivo pharmacological research has provided some evidence that caffeine can have anti-nociceptive actions through blockade of adenosine receptors, inhibition of cyclo-oxygenase-2 enzyme synthesis, or by changes in emotion state. Nevertheless, these actions are only considered in some cases. It is suggested that the actual doses of analgesics and caffeine used can influence the analgesic adjuvant effects of caffeine, and doses that are either too low or too high lead to no analgesic enhancement. Clinical trials suggest that caffeine in doses of more than 65 mg may be useful for enhancement of analgesia. However, except for in headache pain, the benefits are equivocal. While adding caffeine to analgesics increases the number of patients who become free from headache [rate ratio = 1.36, 95% confidence interval (CI) 1.17 to 1.58], it also leads to more patients with nervousness and dizziness (relative risk = 1.60, 95% CI 1.26 to 2.03). It is suggested that long-term use or overuse of analgesic medications is associated with rebound headache. However, there is no robust evidence that headache after use or withdrawal of caffeine-containing analgesics is more frequent than after other analgesics. Case-control studies have shown that caffeine-containing analgesics are associated with analgesic nephropathy (odds ratio = 4.9, 95% CI 2.3 to 10.3). However, no specific contribution of caffeine to analgesic nephropathy can be identified from these studies. Whether caffeine produces nephrotoxicity on its own, or increases nephrotoxicity due to analgesics, is yet to be established.

Onset of analgesia for liquigel ibuprofen 400 mg, acetaminophen 1000 mg, ketoprofen 25 mg, and placebo in the treatment of postoperative dental pain

Ibuprofen is a peripherally acting nonsteroidal anti-inflammatory drug indicated fo ranalgesia, antipyresis, and various arthritic conditions. A solubilized 200 mg liquigel formulation of ibuprofen has been shown to have a more rapid rate of absorption compared with ibuprofen 200 mg tablets. Ibuprofen liquigels have a kinetic profile similar to ibuprofen suspension, with both a higher Cmax and an earlier tmax than any solid tablet. The objective of this single-dose, double-blind, triple-dummy, parallel-group study was to assess the time to onset of relief and overall analgesic efficacy of liquigel ibuprofen 400 mg, ketoprofen 25 mg compared with acetaminophen 1000 mg, and placebo in 239 patients with moderate or severe pain following third molar extractions. Treatments were compared over 6 hours using standard scales for pain intensity and relief and stopwatch onset of meaningful relief. All active treatments provided meaningful relief significantly faster compared with placebo. Ibuprofen provided significantly faster relief compared with acetaminophen and ketoprofen. By the end of the study (6 h), onset of meaningful relief was achieved by 36%, 99%, 96%, and 88% of the patients in the placebo, ketoprofen, ibuprofen, and acetaminophen groups, respectively. The median times to onset of relief were > 6 hours for placebo, 25.5 minutes for ketoprofen, 24.2 minutes for ibuprofen, and 29.9 minutes for acetaminophen. In addition, both ibuprofen and ketoprofen showed statistical superiority over acetaminophen at earlier time points on the time-effect curves for pain relief and pain intensity difference. Consistent results were seen with respect to the 6-hour summary efficacy variables: the three active treatments were significantly better than placebo, and ibuprofen was significantly better than both acetaminophen and ketoprofen. Liquigel ibuprofen 400 mg was shown to provide faster relief and superior overall efficacy compared with ketoprofen 25 mg, acetaminophen 1000 mg, and placebo. No serious adverse effects were reported in this single-dose study.

Analgesic efficacy of a hydrocodone with ibuprofen combination compared with ibuprofen alone for the treatment of acute postoperative pain

Hydrocodone is a semisynthetic opioid with analgesic and antitussive properties qualitatively similar to other opioid agonists. Ibuprofen is a nonsteroidal antiinflammatory agent with analgesic and antipyretic activity and is an effective, primarily peripheral-acting antiinflammatory analgesic. The objective of this clinical trial was to determine the additive analgesic effect of the combination of 15 mg hydrocodone bitartrate with 400 mg ibuprofen, relative to 400 mg ibuprofen alone and placebo, in the treatment of postoperative pain. The single-dose analgesic efficacy of the combination of hydrocodone bitartrate with ibuprofen was compared with ibuprofen alone and placebo in 120 patients with moderate or severe postoperative pain after abdominal surgery. Analgesia was measured during the 6-hour period after dosing based on onset of relief, hourly and summary variables, and duration of effect. A significantly greater proportion of patients treated with the hydrocodone/ibuprofen combination reported onset of relief compared with ibuprofen or placebo; however, the distribution functions for time to onset of relief did not differ among treatments. Hydrocodone with ibuprofen and ibuprofen alone were significantly more effective than placebo for all measures of analgesia. The combination of hydrocodone with ibuprofen was significantly superior to ibuprofen for all hourly analgesic evaluations, weighted sum of pain intensity differences (SPID), total pain relief (TOTPAR), and global rating of study medication. No patients in the hydrocodone with ibuprofen group required analgesic remedication during the 6-hour study period, compared with 25% and 82% in the ibuprofen and placebo groups, respectively. The analgesic superiority of 15 mg hydrocodone bitartrate combined with 400 mg ibuprofen compared with 400 mg ibuprofen alone was demonstrated across many efficacy variables.

Ketorolac for postoperative analgesia in elderly patients

Ketorolac was compared with papaveretum followed by paracetamol plus dextropropoxyphene orally, for postoperative pain relief in elderly orthopaedic patients. Seventy-two patients over the age of 65 years were entered into a double-blind, randomised trial. Pain and pain relief were recorded during an intramuscular and an oral phase, lasting up to 8 days, and a global assessment was made at the end of the study. No difference was demonstrated between the two treatment groups. The incidence of side effects was similar in both groups. It was concluded that ketorolac could provide pain relief equivalent to papaveretum for many patients.

Comparison of intramuscular ketorolac and morphine in pain control after laparotomy

Ketorolac, a prostaglandin synthetase-inhibiting analgesic, was compared with morphine for relief of pain after laparotomy for gynaecological surgery. Eighty patients were studied; they were given either ketorolac 30 mg intramuscularly followed by 10 mg 4-hourly as required, or morphine 10 mg intramuscularly 4-hourly as required, administered in a double-blind, randomised fashion. Pain scores (verbal and visual analogue) were recorded at baseline and assessed at 30 and 60 minutes and then hourly for 6 hours. Pain relief was measured at the same times. Pain and pain-relief scores were further assessed on the evening of day 1 and at 24 hours. Pain scores were similar in the two groups but pain-relief scores were better in the morphine group. A considerable number of patients suffered postoperative nausea and vomiting but there was no difference between the groups. One patient in the ketorolac group had unexplained hypotension. It is concluded that ketorolac can provide effective postoperative analgesia.

Meptazinol and morphine in postoperative pain assessed with a new method for onset and duration

Meptazinol, m-(3-ethyl-1-methyl-hexahydro-1-H-azepin-3-yl) phenol hydrochloride is a centrally active opioid analgesic with a specificity for the mu-1 receptor. It has been reported to lack many of the side effects commonly observed with morphine and morphinelike drugs in man. The objective of this study was to assess the analgesic efficacy and safety of meptazinol (50 mg and 100 mg) relative to morphine (5 mg and 10 mg) when administered intramuscularly for the treatment of postoperative pain. In addition, a new clinical method for measuring onset and duration and a statistical technique for evaluating the study data are presented. One hundred and seventeen patients were evaluated for 6 hours in a randomized double blind, single dose, parallel-groups trial. Estimates of relative potency for hourly pain and relief parameters, and the summary variables sum of pain intensity differences (SPID) and total pain relief (TOTPAR) were performed. The estimate of relative potency of meptazinol to morphine for pain relief was 0.19 at 1/2 hour (i.e. 100 mg of meptazinol was approximately equivalent to 20 mg of morphine). Thereafter, there was a rapid decline of efficacy for meptazinol, with a relative potency estimate of 0.12 at 1 hour and 0.06 at 2 hours. The distribution functions for several time related events were estimated including time to onset, duration and time to remedication. The two drugs had approximately equal onset, but meptazinol had significantly shorter duration. More patients on meptazinol required remedication with a rescue analgesic and at an earlier time than patients on morphine.(ABSTRACT TRUNCATED AT 250 WORDS)

Augmentation of acetaminophen analgesia by the antihistamine phenyltoloxamine

A double-blind, placebo-controlled, parallel-group study was performed to compare the analgesic activity of the combination of 650 mg acetaminophen plus 60 mg phenyltoloxamine citrate with that of 650 mg acetaminophen alone. Two hundred female inpatients who had severe pain associated with a recent episiotomy procedure were randomly assigned to receive a single dose of one of the two active treatments or a placebo. Analgesia was assessed over a 6-hour period. Treatments were compared on the basis of standard subjective scales for pain intensity and relief, a number of derived variables based on these data and two global measures. For essentially all measures, the two active treatments were significantly superior to the placebo control. The combination was significantly superior to acetaminophen alone for all analgesic measures including SPID, TOTAL, and global ratings. The results of this study demonstrate that 60 mg phenyltoloxamine produces significant augmentation of the analgesic activity of 650 mg acetaminophen in postepisiotomy pain.

Analgesic efficacy of ketoprofen in postpartum, general surgery, and chronic cancer pain

This article summarizes the results of five single-dose clinical studies of three pain models: postpartum, postoperative, and chronic cancer pain. The efficacy of ketoprofen (in varying doses from 25 to 225 mg) was compared with one of the following standards: aspirin (650 mg), codeine (90 mg), acetaminophen (650 mg) plus codeine (60 mg), and parenteral morphine (5 mg and 10 mg). The results indicate that ketoprofen in doses as low as 25 mg has analgesic properties significantly superior to those of placebo. For the treatment of postpartum pain, ketoprofen was significantly more effective than aspirin 650 mg but not significantly different from codeine 90 mg. Ketoprofen doses of 50 mg and 150 mg also provided analgesia superior to that with acetaminophen 650 mg plus codeine 60 mg for the management of moderate to severe postoperative pain. Moreover, oral doses of ketoprofen (75 and 225 mg) provided analgesia similar to that obtained with 5 and 10 mg parenteral doses of morphine. Adverse effects related to ketoprofen were relatively minor and infrequent. Ketoprofen was recently approved for use as an analgesic for treatment of mild to moderate pain in total daily doses up to 300 mg; the recommended initial dose is 25 to 50 mg every 6 to 8 hours as necessary.

Analgesic efficacy of piroxicam in the treatment of postoperative pain

Two randomized, double-blind, single-dose studies were conducted to assess the analgesic efficacy and safety of piroxicam for the treatment of moderate or severe postoperative pain. Study 1 evaluated the analgesic efficacy of piroxicam 20 mg compared with that of codeine sulfate 60 mg and placebo. A final patient population of 149 subjects rated pain intensity and pain relief at one half hour and one hour following treatment and then hourly for six hours, with a global assessment made at the completion of 24 hours. Piroxicam 20 mg was significantly more efficacious than placebo for all analgesic variables, including the sum of the pain intensity differences (SPID), total pain relief (TOTAL), percent SPID, duration of effect, and time to remedication. Codeine 60 mg was significantly superior to placebo for percent SPID and some hourly measures. Piroxicam 20 mg was significantly more effective than codeine 60 mg for percent SPID and a few hourly measures including time to remedication. Study 2 assessed the efficacy of piroxicam 20 mg or 40 mg compared with aspirin 648 mg and placebo. Sixty patients rated their pain intensity and relief hourly for 12 hours and at 24 hours after administration of study medication. Both doses of piroxicam were significantly more effective than placebo from Hours 2 to 12 for pain intensity difference (PID) and relief scores, as well as for SPID and TOTAL. Aspirin was significantly more effective than placebo from Hours 2 to 8 for relief and Hours 2 to 10 for PID as well as SPID and TOTAL. Piroxicam 40 mg was significantly more effective than aspirin 648 mg for SPID, TOTAL, and hourly measures beginning with Hour 6 through Hour 12. Piroxicam 20 mg was significantly better than aspirin for a few hourly measures: Hours 7 to 9 for relief and Hour 7 for PID. In addition, effects of piroxicam 20 mg had a significantly longer duration than aspirin. Similarly, piroxicam 20 mg had a significantly longer time to remedication compared with aspirin and placebo. The results of these studies provide evidence in support of the longer duration of analgesic efficacy of piroxicam compared with codeine or aspirin in patients with postoperative pain.

A double-blind, parallel comparison of ketoprofen, aspirin, and placebo in patients with postpartum pain

Our purpose was to evaluate the analgesic efficacy of single oral doses of ketoprofen 25, 50, and 100 mg compared with aspirin 650 mg and placebo in the relief of moderate to severe postepisiotomy, uterine cramping, or cesarean section pain. One hundred and fifty-six patients participated in a randomized, double-blind, stratified, parallel-group study. They were observed over a six-hour period by one nurse-observer. Several of the standard summary measures of analgesia were derived from the interview data, including the sum of pain intensity differences (SPID) and the sum of the hourly relief values (TOTAL). The study showed significant differences between aspirin and placebo for four-hour SPID and several other parameters and between ketoprofen at all dose levels and placebo for the four- and six-hour SPID and many other parameters. The two higher doses of ketoprofen were significantly more effective than aspirin as as assessed by the four- and six-hour SPID, TOTAL, and other summary measures. The low dose of ketoprofen, although not significantly different from aspirin for SPID and TOTAL, showed a significantly faster onset of relief and had a better global rating. This study suggests that 50 mg of ketoprofen may be the clinical dose of choice as an analgesic. There were no adverse effects reported.

An analytic approach to quantifying pain scores

Statistical problems in clinical trials frequently involve fitting regression lines when the underlying data are categorical or ordinal response variables. Usually an ad hoc a priori quantification is used to assign values to these ordinal responses. For pain intensity data collected in analgesic trials, the usual approach is to set none equal to 0, mild equal to 1, moderate equal to 2, and severe equal to 3. While this scheme has been generally accepted, on the basis that for similar clinical trials reasonably similar results are obtained by different investigators, concern exists that the distances between pain scores are probably not equal. A method is presented for quantifying categorical responses so that the resulting scores maximize the simultaneous fit of the dose-response regression lines. The optimal scores derived by this technique may then be used in a bioassay analysis to estimate the relative potency of 2 compounds. As illustrative examples, this method was applied to data from 2 clinical trials and the results were compared to the usual method.

Comparative study of flurbiprofen, zomepirac sodium, acetaminophen plus codeine, and acetaminophen for the relief of postsurgical dental pain

The relative analgesic efficacy and safety of single oral doses of 50 and 100 mg of flurbiprofen (Ansaid, Upjohn) were compared with 100 mg of zomepirac sodium, 650 mg of acetaminophen plus 60 mg of codeine, 650 mg of acetaminophen alone, and placebo in a randomized, double-blind, parallel-group study. A total of 182 patients entered the study with moderate pain from a third molar extraction and were evaluated for six hours. For many efficacy variables, all active treatments were significantly (p less than or equal to 0.05) more effective than placebo. The two doses of flurbiprofen gave approximately similar results, suggesting a plateau effect above 50 mg. With the exception of relief at one hour, there were no significant differences between zomepirac and either dose of flurbiprofen. However, the mean response with zomepirac was greater than with either 50 or 100 mg of flurbiprofen during the first four hours and lower during the last two hours. The analgesic effects of acetaminophen alone were not significantly different from acetaminophen in combination with codeine. At the first hour, acetaminophen plus codeine led to significantly better pain relief than did 100 mg of flurbiprofen. After the first hour, flurbiprofen resulted in greater mean scores than acetaminophen alone or acetaminophen plus codeine, and these differences were significant at the fifth and sixth hours. Five patients had adverse reactions while receiving acetaminophen, acetaminophen plus codeine, or placebo. There were no adverse effects with flurbiprofen or zomepirac.

Comparative efficacy of oral flurbiprofen, intramuscular morphine sulfate, and placebo in the treatment of gynecologic postoperative pain

This single-dose, double-blind, randomized, placebo-controlled study compared the efficacy of 50 mg of oral flurbiprofen (Ansaid, Upjohn), 10 mg of intramuscular morphine sulfate, and placebo in 92 patients with moderate to severe postoperative gynecologic pain. According to pain intensity, pain relief, and pain intensity difference scores, the morphine-treated patients experienced significantly more pain reduction than the other patients by the first hour after treatment. The flurbiprofen group obtained the same level of significant pain relief as the morphine group by two hours after dosing, but relief persisted longer than in the morphine-treated patients. Evaluation of other efficacy variables revealed similar levels of significant pain reduction in both the flurbiprofen and morphine groups compared with the placebo group. Flurbiprofen was well tolerated and led to fewer side effects than either morphine or placebo.

A comparative oral analgesic study of indoprofen, aspirin, and placebo in postpartum pain

The purpose of this study was to evaluate the analgesic efficacy and adverse effect liability of single oral doses of indoprofen, 50 mg, 100 mg, and 200 mg, compared with aspirin, 300 mg and 600 mg, and placebo in the relief of moderate to severe postpartum pain. Two hundred-ten patients entered a randomized, double-blind, parallel group study and were evaluated over a six-hour period by a single nurse-observer. There was a significant imbalance in the distribution of pain types across treatments that compromises the interpretation of the results. In addition to analyzing the data from all patients, the subsets with episiotomy/cesarean section pain and uterine cramp pain were examined separately. The latter group had too few patients to permit distinction between drugs. The 100 mg and 200 mg doses of indoprofen were significantly (P less than or equal to .05) more effective than placebo for many variables including the following summary values: sum of pain intensity difference (SPID), sum of hourly relief values (TOTPAR), and % SPID for all patients as well as in the subset of patients with episiotomy/cesarean section pain. Aspirin, 600 mg, was also significantly more effective than placebo for many of the same measures of analgesia in the episiotomy/cesarean section subset. Pairwise differences were also seen between placebo and aspirin, 300 mg, but on fewer variables. Indoprofen, 100 mg, was significantly more effective than aspirin, 600 mg, at hour 6 for pain intensity difference (PID) in the episiotomy/cesarean section subset. The effect of indoprofen appeared to plateau above 100 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Double-blind parallel comparison of single oral doses of ketoprofen, codeine, and placebo in patients with moderate to severe dental pain

Ketoprofen, 25, 50, and 100 mg, was compared with 90 mg codeine and placebo for relief of pain due to removal of impacted third molar teeth. Treatment was self-administered as a single oral dose under double-blind conditions in five parallel groups established by a random code in healthy young adults. Based on 129 patient evaluations of pain experience and pain relief, ketoprofen was shown to have a more rapid onset and longer duration of action than codeine. In the derived variables of SPID (Sum of Pain Intensity Differences) and TOPAR (Total Pain Relief), all three doses of ketoprofen, with no dose-related differences among them, were found to provide statistically superior analgesia to codeine and placebo. All five treatments were associated with some adverse reactions.

A double-blind parallel comparison of ketoprofen, codeine, and placebo in patients with moderate to severe postpartum pain

A total of 152 patients were treated at a single center in a single-dose, double-blind parallel study designed to compare the safety and efficacy of 25, 50, and 100 mg ketoprofen to 90 mg codeine and placebo in patients with moderate to severe postpartum pain (i.e., postepisiotomy, uterine cramping, or cesarean section pain). The analgesic responses to all three doses of ketoprofen and 90 mg codeine were superior to placebo and were not significantly different from each other. No dose-related response was observed with ketoprofen. The number of side effects was significantly greater (P = 0.001) among patients receiving codeine (six patients) than among those receiving ketoprofen (three patients).

Analgesic effects of oral propiram fumarate, codeine sulfate and placebo in postoperative pain

Our purpose was to evaluate the analgesic efficacy and safety of single oral doses of propiram fumarate 50 mg, codeine sulfate 60 mg and placebo in the relief of moderate to severe postoperative pain. One hundred and twenty patients completed a randomized, double-blind, single-dose, stratified, parallel-groups trial and were observed for either 4 or 6 hours. Based upon each of the summary efficacy measures--SPID, % SPID and TOTAL--propiram and codeine were approximately equally effective and both were statistically superior to placebo. Propiram was significantly more effective than codeine at hour 5 for Pain Intensity Difference. Two adverse effects were attributed to propiram. Propiram fumarate 50 mg is an effective oral analgesic similar to codeine sulfate 60 mg, with the possibility of a longer duration of action.

Analgesic effect of graded doses of flurbiprofen in post-episiotomy pain

Our purpose was to evaluate the analgesic efficacy and safety of single oral doses of flurbiprofen 25, 50 and 100 mg, aspirin 600 mg, and placebo in the relief of moderate to severe post-episiotomy pain. One hundred and fifty-two evaluable patients completed a randomized, double-blind, stratified, parallel groups study. They were observed over a six hour period by one nurse-observer. Based upon each of the summary efficacy measures SPID, TOTAL and PEAK % and most of the hourly direct measures of pain intensity and pain relief, each of the four active treatments were statistically superior to placebo. Flurbiprofen 25 mg appeared to be slightly less effective than aspirin 600 mg, but the differences were not statistically significant. Flurbiprofen 50 and 100 mg were quite similar and were significantly more effective than aspirin 600 mg and flurbiprofen 25 mg. There were no observed or reported adverse effects.

Quantitative differences in aspirin analgesia in three models of clinical pain

An analysis was made of data from over 4000 postepisiotomy, uterine cramping, and postsurgical patients complaining of moderate or severe pain. They had received 325, 650, or 1300 mg aspirin or placebo while they were subjects in 10 analgesic clinical trials. On the average, for the same verbally expressed pain intensity level and the same treatment, more relief was obtained by a patient with uterine cramping than one with episiotomy pain, who in turn obtained more relief than a patient with surgical pain. A new mathematical model which characterizes the probability that an analgesic provides complete relief as a function of dose, severity of pain intensity, and pain etiology is developed. The model utilizes the data itself to estimate the numerical score corresponding to verbal pain intensities. The results indicate that the numerical score quantifying severe surgical pain is 1.4 times greater than the score for severe episiotomy pain, which in turn is 3.2 times greater than the score for severe uterine cramping. Clinical trials must be designed to take these differences into account. Also, clinicians must be cognizant of such differences when choosing among drugs and dosages for patients with different pain intensity and etiology.

Analgesic efficacy of zomepirac sodium in patients with pain due to cancer

In a single-dose, a double-blind crossover study in 40 patients with chronic pain due to advanced cancer, zomepirac sodium (Zomax), a new, single-entity, non-narcotic analgesic, was compared to oxycodone with APC (Percodan) and placebo. Both a verbal and a curvilinear visual analog scale were used in the study, and the results obtained were comparable. Zomepirac sodium, 100 mg, provided analgesia equal to oxycodone with APC in all assessments of pain intensity and pain relief. The analgesic activity of zomepirac sodium was apparent by 1 hour, reached a peak between 3 and 4 hours after administration, and lasted at least 6 hours. Zomepirac sodium, 100 mg, appears to be an acceptable alternative to narcotic combinations such as oxycodone with APC in the management of moderate to severe cancer pain. The visual analog scale presented appears to be useful in the evaluation of analgesic efficacy and appears to be acceptable as an alternative to the more conventional verbal scale.

Adverse effects of commonly ordered oral narcotics

Approximately equianalgesic oral doses of codeine, an oxycodone compound resembling Percodan, and pentazocine were compared for adverse effects in a double-blind, randomized study of four doses of each drug given over two days to 247 postsurgical patients with pain. Placebo and parenteral morphine were also treated as negative and positive controls, respectively. Approximately 50 patients each received one of the five drugs. Codeine, pentazocine, and morphine had the same incidence of adverse effects (22 to 28 per cent). One capsule of oxycodone compound was the analgesic equivalent of 12.5 mg morphine with an adverse effect incidence of 4 per cent (placebo 8 per cent). Smoking made no difference in analgesic effect or adverse effects. Analgesics given in the evening intervening between the two days may have affected the analgesic performance of placebo.

Analgesic combinations with orphenadrine in oral post-surgical pain

Two hundred male and female patients underwent a variety of oral surgical procedures and were treated afterwards in four test groups. They took a combination of orphenadrine (25 mg) and acetaminophen (325 mg), either drug alone, or placebo. A double-blind study design was used. All patients had moderately severe baseline pain intensity; post-treatment pain relief was recorded at 30 minutes, one, two, four and six hours. A back-up analgesic (codeine-ASA) was made available if needed. Pain intensity difference (PID) and sums of pain intensity difference (SPID) were calculated using established analgesic study techniques. Statistical analyses indicated better analgesic efficacy in both PID and SPID scores for the orphenadrine-acetaminophen combination over the three other treatments. This was evident at 30 minutes and continued through the sixth hour. Each active drug, in turn, was also significantly better throughout than placebo for pain relief. Sub-groups in each treatment regimen required additional pain relief prior to six hours, with significantly more placebo than orphenadrine-acetaminophen patients needing remedication. Side-effect incidence was very low and randomly distributed among the four groups.

A comparative analgesic study of propoxyphene, fenoprofen, the combination of propoxyphene and fenoprofen, aspirin, and placebo

Groups of 27 inpatients with moderate or severe postoperative, fracture, or somatic pain were given single oral doses of propoxyphene napsylate (P), fenoprofen calcium (F), combinations of P and F, aspirin, or placebo. The increasing rank order for effectiveness, with doses in milligrams, was placebo, P50, aspirin 650, F600, F50, P50 + F50, F200, P50 + F600, P50 + F200, P200 + F50, P200, P200 + F200, and P200 + F600. The overall analgesic response to propoxyphene in this dose range (50 to 200 mg) increased linearly with increasing doses. The fenoprofen response also increased in proportion to the dose up to 200 mg; the overall response to 600 mg was not significantly different from that to 200 mg. Propoxyphene napsylate and fenoprofen calcium had additive analgesic effects. There were no drug-related adverse reports.

Hypnotic activity of diphenhydramine, methapyrilene, and placebo

In a double-blind controlled study, an oral dose of diphenhydramine hydrochloride (12.5, 25, or 50 mg), methapyrilene fumarate (36, 72, or 144 mg), or placebo was administered to 1295 post-partum patients if they complained of, or anticipated, a sleep problem. Hypnotic activity was assessed clinically by subjective and objective techniques. Methapyrilene and diphenhydramine, at all doses, were found to be effective hypnotics in comparison to placebo, based on sleep latency, sleep duration, awakening in the night, global evaluation, and morning alertness. Increasing the dose of these drugs, in the range studied, produced a minimal increase in effectiveness.

Estimates of doses of antiinflammatory drugs in man by testing for analgesic potency. I. 1-isopropyl-4 phenyl-7-methyl-2 (1H) quinazolone versus aspirin

Dosage estimates of antiinflammatory drugs in human arthritis Phase II trials are difficult to obtain and prolong such trials unnecessarily. Antiinflammatory drugs almost always have analgesic properties in man and good dose estimates for analgesic activity can be obtained. In 140 patients with surgical pain, 300, 600, and 1200 mg of aspirin were compared to 75, 150, and 300 mg of 43-715 (1-isopropyl-4-phenyl-7-methyl-2 (1H) quinazolone), an antiinflammatory quinazolone derivative, for analgesia in a double-blind trial using subjective response methodology. The test drug was shown to be analgesic at a level four times more potent, milligram for milligram, than aspirin, an estimate that should be useful for later definitive Phase II trials in arthritis.

Application of nonparametric procedure for bioassay data to the evaluation of analgesics in man

Parametric tests for bioassay data are commonly applied to scores of pain intensity and relief for the assessment of potency ratios of analgesic drugs. It has been demonstrated, however, that scores derived from semiquantitative scales often deviate from normal distribution. In addition, when scores decrease as a consequence of analgesic treatment, the variances may be nonhomogenous. Both parametric and nonparametric procedures have been employed in this study for the evaluation of results of a double-blind multicenter trial of the analgesic effect of indoprofen and ASA (both drugs at three dose levels) and placebo in episiotomy pain. There was a good agreement between potency ratios obtained with the two assays. Peak PID appeared a less efficient means of estimating potency ratio than other measurements such as SPID and TOTPAR. The nonparametric test for quantitative bioassay appears to be a valid statistical procedure for evaluating results of clinical trials, and it does not imply any assumptions as to the type of distribution of the data.

Buprenorphine hydrochloride: determination of analgesic potency

An open evaluation of relief from severe pain following major abdominal operations was carried out on at least ten patients, who had given written consent, with 0.1 to 0.4 mg doses of buprenorphine hydrochloride administered intramuscularly. Statistical analysis of the data showed that 0.3 mg of this compound provided quite satisfactory relief from pain for up to six hours. Seven more consenting patients were given buprenorphine hydrochloride 0.5 to 0.6 mg, but they did not receive much greater or longer pain relief than those receiving 0.3 to 0.4 mg. However, the latter patients were younger and heavier. It was concluded that buprenorphine hydrochloride 0.2 to 0.4 mg provided relief of severe pain probably as well as is observed with morphine 10 mg for the average-size patient, but the duration of pain relief with the new compound is substantially longer than with other strong analgesics previously tested. The only common side effect noted was drowsiness, which was observed during the analgesic action of the compound. No appreciable alterations were seen in the respiration, pulse rate and blood pressure. On the basis of these tests, buprenorphine hydrochloride appears to be a satisfactory analgesic for severe postoperative pain, and it deserves extensive study.