Identification of novel cyclooxygenase-2 selective inhibitors using pharmacophore models.

In the present study we have investigated whether pharmacophore models may account for the activity and selectivity of the known cyclooxygenase-2 (COX-2) selective inhibitors of the phenylsulfonyl tricyclic series, i.e., Celecoxib (1) and Rofecoxib (3), and whether transferring this structural information onto the frame of a nonsteroidal antiinflammatory drug (NSAID), known to tightly bind the enzyme active site, may be useful for designing novel COX-2 selective inhibitors.

Differential binding mode of diverse cyclooxygenase inhibitors.

Non-steroidal anti-inflammatory drugs (NSAIDs) are competitive inhibitors of cyclooxygenase (COX), the enzyme that mediates biosynthesis of prostaglandins and thromboxanes from arachidonic acid. There are at least two different isoforms of the enzyme known as COX-1 and -2. Site directed mutagenesis studies suggest that non-selective COX inhibitors of diverse chemical families exhibit differential binding modes to the two isozymes.

Structure-based design of cyclooxygenase-2 selectivity into ketoprofen.

We have recently described how to achieve COX-2 selectivity from the non-selective inhibitor indomethacin (1) using a combination of a pharmacophore and computer 3-D models based on the known X-ray crystal structures of cyclooxygenases. In the present study we have focused on the design of COX-2 selective analogues of the NSAID ketoprofen (2). The design is similarly based on the combined use of the previous pharmacophore together with traditional medicinal chemistry techniques motivated by the comparative modeling of the 3-D structures of 2 docked into the COX active sites.

Comparison of the Efficacy and Tolerability of Dexketoprofen and Ketoprofen in the Treatment of Primary Dysmenorrhea.

Dexketoprofen, the pure S(+)-enantiomer of ketoprofen, is a promising new analgesic, but few clinical trials have yet examined its efficacy and tolerability. In this study, patients with a history of primary dysmenorrhea were treated with dexketoprofen doses of 12.5 and 25 mg, ketoprofen 50 mg, and placebo using a randomized, four-way crossover design.

Clinical Comparison of Dexketoprofen Trometamol and Dipyrone in Postoperative Dental Pain.

A total of 125 outpatients with moderate to severe pain after surgical removal of one impacted third molar were randomly assigned to receive dexketoprofen trometamol 12.5 or 25 mg or dipyrone 575 mg. For first-dose assessments, patients rated their pain intensity and its relief at regular intervals.

Pharmacokinetics of Dexketoprofen Trometamol in Healthy Volunteers After Single and Repeated Oral Doses.

The pharmacokinetics of dexketoprofen trometamol were evaluated in two studies using healthy volunteers. In the first study, the relative bioavailability of a single oral capsule of dexketoprofen free acid 25 mg or dexketoprofen trometamol 25 mg (given as 37 mg of the trometamol salt) was compared to ketoprofen 50 mg in 18 healthy volunteers. In the second study, the pharmacokinetics and tolerability of oral dexketoprofen trometamol in tablet form were evaluated after either a single 25 mg dose (24 volunteers) or a repeated dose of 25 mg twice daily for 7 days (12 volunteers).

Bioavailability of S(+)-Ketoprofen After Oral Administration of Different Mixtures of Ketoprofen Enantiomers to Dogs.

Recent reports have disagreed on whether the bioavailability of S(+)-ketoprofen is affected by the presence of R(-)-ketoprofen. To examine this directly, we designed a randomized crossover study in beagle dogs. [ C]- S(+)-ketoprofen trometamol and R(-)-ketoprofen trometamol were administered in the following percentage ratios: A, 99:1; B, 95:5; C, 90:10; D, 70:30; E, 50:50.

Antinociceptive Effects of S(+)-Ketoprofen and Other Analgesic Drugs in a Rat Model of Pain Induced Uric Acid.

We investigated the antinociceptive properties of dexketoprofen trometamol (S(+)-ketoprofen tromethamine salt; SKP), a new analgesic, antiinflammatory drug, using the pain-induced functional impairment model in the rat (PIFIR), an animal model of arthritic pain. SKP was compared with racemic ketoprofen tromethamine salt (rac-KP), R(-)-ketoprofen tromethamine salt (RKP), ketorolac (KET), and morphine (MOR). We also assessed the effects of flurbiprofen (rac-FB) and its enantiomers (SFB and RFB) in the same model.

Intestinal Ulcerogenic Effect of S(+)-Ketoprofen in the Rat.

Nonsteroidal antiinflammatory drugs (NSAIDs) inhibit prostaglandin synthesis in the gastrointestinal mucosa, which can lead not only to stomach ulcers but also ulcers in the small and large intestines. Ulcers of the small intestine are less common than those of the stomach, but intestinal lesions are more life threatening. Although the R(-)-enantiomers of the arylpropionic acid (APA) class of NSAIDs are assumed to lack the toxic effects of cyclooxygenase inhibition, they may contribute to the ulcerogenicity of racemates.

Comparison of Dexketoprofen Trometamol and Ketoprofen in the Treatment of Osteoarthritis of the Knee.

Dexketoprofen, the active enantiomer of the racemic compound ketoprofen, is a new nonsteroidal antiinflammatory drug (NSAID) of the arylpropionate family. The efficacy and safety of dexketoprofen trometamol were compared with the equivalent enantiomeric dose of ketoprofen in a multicenter, randomized, double-blind 3-week trial of adult outpatients with pain due to osteoarthritis of the knee. After a washout period of 7-15 days, patients were randomly assigned to receive either dexketoprofen trometamol 25 mg tid (N = 89) or ketoprofen 50 mg tid (N = 94).

The Effect of Food and an Antacid on the Bioavailability of Dexketoprofen Trometamol.

This randomized three-way, crossover pharmacokinetic study was performed to determine whether food or an antacid alters the bioavailability of dexketoprofen trometamol. A total of 24 healthy volunteers received three single 25 mg doses of dexketoprofen trometamol administered either in fasting condition, after an antacid (Maalox ), or after a high-fat breakfast. Each volunteer received the three treatments in a randomized order, with a 7-day washout period between treatments.

Clinical Comparison of Dexketoprofen Trometamol, Ketoprofen, and Placebo in Dental Pain.

The efficacy and tolerability of single doses of dexketoprofen trometamol12.5 mg, 25 mg, and 50 mg and ketoprofen 50 mg were compared in this double-blind, randomized, placebo-controlled study of 210 patients with moderate to severe pain after removal of one mandibular impacted third molar tooth. Pain intensity and pain relief were monitored for 6 h after administration of medication using visual analogue and verbal rating scales.

Analgesic, Antiinflammatory, and Antipyretic Effects of S(+)-Ketoprofen In Vivo.

Many studies indicate that the S-enantiomers of arylpropionic (APA) nonsteroidal antiinflammatory drugs (NSAIDs) are the pharmacologically active enantiomers. S(+)-ketoprofen (dexketoprofen) stereoselectively inhibits cyclooxygenase (COX) in vitro but very little is known about the differential activity of ketoprofen enantiomers in vivo. We examined the analgesic, antiinflammatory, and antipyretic activities of S(+)-ketoprofen in rats and mice.

Effects of R- and S-enantiomers of chiral non-steroidal anti-inflammatory drugs in experimental colitis.

Prostaglandins appear to play an important role in down-regulating intestinal inflammation and promoting repair of injury. In experimental colitis, inhibition of prostaglandin synthesis with nonsteroidal anti-inflammatory drugs (NSAID) leads to marked exacerbation of tissue injury. It has been suggested that the ability of chiral NSAID to inhibit prostaglandin synthesis is completely attributable to the s-enantiomer, while the r-enantiomer is a much weaker inhibitor.