Itic Zighelboim

Effect of caffeine on acetaminophen analgesia

Our objective was to determine the value of caffeine in combination with acetaminophen in the relief of pain from uterine cramping, episiotomy, and third molar extraction. In the dental study, 173 patients received two or four tablets of 500 mg acetaminophen or the combination of 500 mg acetaminophen and 65 mg caffeine. In the three postpartum studies, 1345 patients received one, two, or three tablets of acetaminophen, the combination, or a placebo. The mean scores for the summary variable percent sum of the pain intensity differences (% SPID) were higher in all for the combination than for acetaminophen alone, and in two studies the null hypothesis of no differences was rejected. The relative potency estimates for % SPID were 1.9, 1.8, and 1.3 for the three studies in which bioassays could be performed and the pooled relative potency was 1.7 with a 95% confidence interval of 1.1 to 3.1. The results were essentially the same among pain models and among patient groups with similar habitual caffeine consumption. Onset of analgesia was also faster with the combination. We conclude that caffeine enhances the analgesic efficacy of acetaminophen.

Analgesic oral efficacy of tramadol hydrochloride in postoperative pain.

Tramadol hydrochloride is a synthetic opiate agonist with a plasma elimination half‐life of 5 to 6 hours and peak plasma levels at about 1½ hours. It derives its activity from attachment to the μ‐receptor and blockage of norepinephrine reuptake. The purpose of this single‐dose, double‐blind, placebo‐controlled study was to determine the analgesic effectiveness of an oral administration of two dose levels of tramadol hydrochloride (75 or 150 mg) compared with the combination of 650 mg acetaminophen plus 100 mg propoxyphene napsylate in 161 patients with severe postoperative pain after cesarean section. Analgesia was assessed over a 6‐hour period. Treatments were compared on the basis of standard scales for pain intensity and relief and a number of derived variables based on these data. A global rating of the study medication was also used to compare treatments. The three active treatments were effective analgesics, statistically superior to placebo for many hourly and summary measures. A dose response was seen between the two tramadol doses, with the 150 mg dose providing significantly greater analgesia over the lower dose. The 75 mg dose of tramadol was generally more effective than the acetaminophen‐propoxyphene combination after hour 2, and significantly so for some hourly time points, as well as for the global rating of the medication. The 150 mg dose of tramadol was significantly more effective than the acetaminophen‐propoxyphene combination from hour 2 through hour 6 for the sum of pain intensity differences and total pain relief scores, as well as for the global rating of the medication. Tramadol hydrochloride at both dose levels is an effective analgesic agent and at 150 mg is statistically superior to the acetaminophen‐propoxyphene combination. No serious adverse effects were observed; however, dizziness was more frequently reported with 150 mg tramadol.

Ketoprofen, acetaminophen plus oxycodone, and acetaminophen in the relief of postoperative pain

Ketoprofen (Orudis) is a nonsteroidal anti‐inflammatory drug that is currently approved in the United States for the management of mild to moderate pain. The objective of this trial was to determine the effectiveness of orally administered ketoprofen in the management of severe postoperative pain. This randomized, double‐blind parallel study compared the efficacy and safety of single doses of 100 mg or 50 mg ketoprofen, the combination of 650 mg acetaminophen plus 10 mg oxycodone hydrochloride, 650 mg acetaminophen, or placebo in 240 patients with severe postoperative pain after cesarean section. Analgesia for the first dose was assessed over an 8‐hour period. Multiple doses of 100 mg or 50 mg ketoprofen and the combination at half the dose (325 mg acetaminophen plus 5 mg oxycodone) were also assessed for up to 7 days. The 100 and 50 mg doses of ketoprofen and the combination were statistically superior to acetaminophen and placebo for many analgesic measures. A dose response was observed between the two doses of ketoprofen, with the 100 mg dose providing significantly greater analgesia over the lower dose. Ketoprofen, 100 mg, was at least as effective as the combination and its effects lasted longer, with the exception of hour 1 when the combination was superior. Remedication time for the group receiving 100 mg ketoprofen was significantly longer than for the other treatment groups. Significantly more patients who took repeated doses of the combination (84%) than those who took either dose of ketoprofen (70%) had adverse effects. Ketoprofen at both dose levels was shown to be effective, long‐lasting, and well tolerated, and it should be considered as a viable option for the management of moderate to severe postoperative pain.

Ibuprofen, zomepirac, aspirin, and placebo in the relief of postepisiotomy pain

Our purpose was to compare the analgesic efficacy of single oral doses of ibuprofen, zomepirac, aspirin, and placebo in severe postepisiotomy pain. One hundred twenty subjects participated in a double‐blind, single‐dose, parallel‐group, 4‐hr trial comparing 400 mg ibuprofen, 100 mg zomepirac sodium, 600 mg aspirin, and placebo. For most parameters, including the sum of the pain intensity differences (SPID) and the sum of the hourly pain relief values (TOTAL), which are summary variables, each of the drugs was more effective than placebo. Ibuprofen was more effective than aspirin and zomepirac. Zomepirac and aspirin were equally effective for most of the analgesic variables. There were no adverse effects. Ibuprofen, 400 mg, is an effective oral analgesic and is more effective than 100 mg zomepirac and 600 mg aspirin in most parameters of pain.

Onset and duration of analgesia of diclofenac potassium in the treatment of postepisiotomy pain.

A double-blind, placebo-controlled, parallel group study was performed to compare the analgesic efficacy of diclofenac potassium (25, 50, or 100 mg) with that of aspirin (650 mg), or placebo. Two hundred fifty-five inpatients with severe postepisiotomy pain were randomly assigned to receive a single oral dose of one of the four active treatments or placebo. Analgesia was assessed over an 8-hour period. Treatments were compared on the basis of standard scales for pain intensity and relief and a number of derived variables based on these data, as well as two global ratings of the study medication. All active treatments were effective analgesics statistically superior to placebo for many hourly and summary measures, including the global ratings. Diclofenac potassium (50 and 100 mg) was statistically significantly superior to aspirin at half-hour and for many other hourly scores from hour 3 on. The 4− and 8-hour sum of the pain intensity difference and total pain relief scores reflected the superiority of diclofenac potassium to aspirin. In addition, the 100-mg dose was significantly more efficacious than the 25-mg dose of diclofenac potassium. The probability of obtaining onset was significantly better for all active treatments than for placebo; however, the median onset times were similar for all treatments. The duration of effect, as measured by mean pain intensity difference and relief scores, was better for diclofenac potassium than aspirin, and these differences were significant for the 50− and 100-mg doses. The probability of pain returning to baseline was significantly less for the diclofenac groups than for placebo or aspirin groups. In addition, significantly fewer patients treated with diclofenac (25, 50, or 100 mg) or aspirin (650 mg) required remedication during the 8-hour study period as compared with those treated with placebo. Diclofenac potassium is an effective analgesic in the range of aspirin (650 mg) at the 25-mg dose and superior in efficacy and longer lasting than aspirin at the 50− and 100-mg doses. The onset of analgesia was similar for aspirin and diclofenac potassium.

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 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.

Human perinatal distribution of butorphanol

The perinatal distribution of butorphanol was demonstrated in relation to maternal-neonatal transfer and colostrum/milk excretion in obstetric patients. Parenteral butorphanol passed the placental barrier and was found in neonatal cord serum. The mean neonatal serum concentration of butorphanol was not different from the mean maternal serum concentration of butorphanol, following a 1 or 2 mg intramuscular dose. Butorphanol was detected in the milk of lactating women following oral and intramuscular administration. Serum and milk concentrations appeared to be parallel with time. This observation was confirmed by the constancy of the mean milk-to-serum concentration ratio (0.7 intramuscular, 1.9 oral). We calculated that 4 micrograms would be the maximum amount of butorphanol, which would be expected to be present in the full daily milk output (1 L) following administration four times a day of 2 mg intramuscular or of 8 mg oral doses. An oral dose of 4 micrograms to an infant weighing 4 kg corresponds to the negligible oral dose of 0.7 mg to a 70 kg adult. The demonstrated safety and efficacy of butorphanol as an obstetric analgesic and the characteristics of the maternal-neonatal transfer and milk excretion are indicative of the potential excellence of this agent for obstetric use.

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.

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.

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.