Analgesic efficacy of liquid ketoprofen compared to liquid dipyrone and placebo administered orally as drops in postepisiotomy pain. A double-blind comparison of parenteral dipyrone and pethidine in the treatment of post-operative pain. Comparison of the onset and duration of the analgesic effect of dipyrone, 1 or 2 g, by the intramuscular or intravenous route, in acute renal colic. Intravenous dipyrone for the acute treatment of episodic tension-type headache: a randomized, placebo-controlled, double-blind study. Efficacy and tolerance of oral dipyrone versus oral morphine for cancer pain. Double-blind crossover comparison of ketoprofen, naproxen, and placebo in patients with primary dysmenorrhea.
The objective of this single-center, single-dose, double-blind randomized parallel group study was to evaluate the analgesic efficacy of a new liquid formulation of ketoprofen at two dose levels (25 mg or 50 mg) compared to a commercially available liquid form of dipyrone 500 mg and placebo with all treatments administered as drops to patients with severe postepisiotomy pain.
                The study was designed with a sample size of 69 patients per treatment for a total of 276 patients. However, due to administrative changes at the site, the study was prematurely terminated; thus only 108 patients (26 to 28 patients per treatment), 18 years or older, with severe postepisiotomy pain were randomized to one of the four treatments. Treatments were assessed over a 6-hour period using standard scales for pain intensity and pain relief and a number of derived variables based on these data. Since the study medications were not identical in appearance, the preparation and administration of the study medication, and the observation of the patient, were carried out by two different individuals to maintain double-blind conditions.
                All active treatments were significantly superior to placebo for several measures of analgesia including 4-hour and 6-hour SPID and TOTPAR scores. The global rating was assessed as "good" or "excellent" by over 75% of the patients in the active treatment groups compared to 7.4% of the patients in the placebo group. Reduction in pain intensity was very similar for the two-dose levels of ketoprofen and the comparator dipyrone 500 mg.
                Ketoprofen 25 mg or 50 mg, and dipyrone 500 mg seem to be equally suited for use as pain relief medication after minor surgery, as well as episiotomy. This study did not demonstrate a need for more than 25 mg of ketoprofen in postepisiotomy pain. All treatments were well tolerated. No adverse events were reported. A double-blind trial was carried out in 100 patients with moderate to severe post-operative pain to compare the analgesic effectiveness over a 6-hour period of single intramuscular injections of 2.5 g dipyrone and 100 mg pethidine. Maximum pain relief was seen 2 hours after drug administration in both groups and there was no statistically significant difference in responses. No side-effects were reported. In a double-blind, double-dummy randomized controlled clinical trial, the onset and duration of the analgesic effect of dipyrone, 1 or 2 g, and diclofenac sodium, 75 mg, by either the i.m. or the i.v. route were compared in 293 patients (aged 18-70 years) with acute renal colic. A level of > or = 50 mm on the 100-mm visual analogue scale was required for inclusion in the study. Patients were randomly allocated to six treatment groups, receiving dipyrone 1 g i.m., dipyrone 1 g i.v., dipyrone 2 g i.m.;, dipyrone 2 g i.v., diclofenac sodium 75 mg i.m.; and diclofenac sodium 75 mg i.v., respectively. Evaluations were performed at 10, 20, 30, and 60 min and 2, 4, and 6 h after treatment (time 0). Primary efficacy end points included course of pain, total pain, percentage of patients with a pain improvement of 50% or more at each evaluation time, pain intensity evaluated by the investigator on a 0-3 scale, and differences in pain intensity. The analgesic response was more marked and prolonged among patients receiving dipyrone 2 g i.m. or dipyrone 2 g i.v. There were no significant differences between dipyrone 1 g and diclofenac sodium 75 mg, by either the i.m. or the i.v. route. All treatment regimens were well tolerated. Acute headaches are responsible for a significant percentage of the case load at primary care units and emergency rooms in Brazil. Dipyrone (metamizol) is easily available in these settings, being the most frequently used drug. We conducted a randomized, placebo-controlled, double-blind study to assess the effect of dipyrone in the acute treatment of episodic tension-type headache. Sixty patients were randomized to receive placebo (intravenous injection of 10 ml saline) or 1 g dipyrone in 10 ml saline. We used seven parameters of analgesic evaluation. The patients receiving dipyrone showed a statistically significant improvement (P<0.05) of pain compared to placebo up to 30 min after drug administration. The therapeutic gain was 30% in 30 min and 40% in 60 min. The number of patients needed to be treated for at least one to have benefit was 3.3 in 30 min and 2.2 in 60 min. There were statistically significant reductions in the recurrence (dipyrone = 25%, placebo = 50%) and use of rescue medication (dipyrone = 20%, placebo = 47.6%) for the dipyrone group. Intravenous dipyrone is an effective drug for the relief of pain in tension-type headache and its use is justified in the emergency room setting. In a double-blind, randomised and parallel clinical trial, two oral doses of dipyrone (1 and 2 g) administered every 8 h were compared with 10 mg of oral morphine given every 4 h for the relief of chronic cancer pain. A total of 121 patients with cancer pain without gastric involvement participated in a 7-day treatment course and were allocated to receive either dipyrone 1 g (n = 41), dipyrone 2 g (n = 38) or morphine (n = 42). Drug efficacy was analysed according to the degree of pain relief using a 100-mm visual analogue scale, and the number of patients who decided to increase the dose of the analgesic drug on day 4. The analgesic effect of dipyrone, 2 g every 8 h, was similar to that of morphine. The efficacy of both schedules was significantly greater than that of dipyrone, 1 g every 8 h. Dipyrone at either 1 or 2 g doses tended to be better tolerated than morphine, although the differences were not statistically significant. Sixty-three women, aged 18 to 39 years, with primary dysmenorrhea received 25 mg, 50 mg, or 75 mg of ketoprofen, 500 mg of naproxen, or placebo as a first dose at the onset of moderate or severe pain. Each patient received three treatments and each treatment was tested in 36 patients. Mean pain relief scores (on a five-point scale) indicated a significant analgesic response for all active treatments; superiority over placebo was shown by ketoprofen 50 mg for six hours, by ketoprofen 75 mg for five hours, by ketoprofen 25 mg for four hours, and by naproxen for four hours. The onset of pain relief and peak relief were reached faster and pain relief lasted longer after 75 mg and 50 mg of ketoprofen than after 25 mg of ketoprofen or 500 mg of naproxen, which in turn were superior to placebo. Treatment was rated good to excellent by 20 patients after 25 mg of ketoprofen, by 26 after 50 mg, and by 28 after 75 mg, and by 22 after naproxen and 11 after placebo. The incidence of side effects was similar in the ketoprofen-treated and naproxen-treated patients.
Based on very limited information, single dose dipyrone 500 mg provides good pain relief to 70% of patients. For every five individuals given dipyrone 500 mg, two would experience this level of pain relief who would not have done with placebo, and fewer would need rescue medication, over 4 to 6 hours.