Effects of food and sucralfate on the pharmacokinetics of naproxen and ketoprofen in humans.

Compliance to nonsteroidal anti-inflammatory drug therapy can be compromised by gastrointestinal side effects. To overcome this problem, food, antacid, or sucralfate are often co-administered with nonsteroidal anti-inflammatory drugs. Three studies were conducted on three groups of 12 volunteers in order to determine the influence of food or sucralfate on the pharmacokinetics of naproxen and ketoprofen. In a crossover experimental design, the first group received a single dose (50 mg) of ketoprofen with and without sucralfate (2 g). The second group received single (100 mg) and multiple (100 mg twice daily for 5 days) doses of enteric-coated ketoprofen with and without food. The third group received single (500 mg) and multiple (500 mg twice daily) doses of naproxen with and without sucralfate. Multiple blood samples were drawn and analyzed by high-pressure liquid chromatography. Short- and long-term pharmacokinetic parameters were determined. Results in group 1 showed that neither ketoprofen bioavailability nor maximal plasma concentration and time to reach maximal concentration were affected by the administration of sucralfate. However, in group 2 absorption of ketoprofen was markedly affected by food. In the presence of food, maximal plasma concentration decreased from 10.7 to 6.3 micrograms/ml after single-dose administration and 12.1 to 8.0 micrograms/ml after multiple-dose administration. The time to reach maximal plasma concentration was also modified by food, increasing from 2.8 to 7.1 hours after single-dose and 2.8 to 7.6 hours after multiple-dose administration. Food caused a significant decrease in the bioavailability of ketoprofen (over 40 percent) following both single-dose (23.8 versus 13.1 micrograms.hour/ml) and multiple-dose (29.3 versus 16.8 micrograms.hour/ml) administration. Results obtained in group 3 showed that sucralfate reduced the absorption rate constant of naproxen, from 1.7 to 1.2 hours-1 and from 1.5 to 0.7 hour-1 following single- and multiple-dose administration, respectively. However, bioavailability of naproxen was not affected by sucralfate administration. Overall, these studies have shown that sucralfate does not alter the pharmacokinetics of naproxen and ketoprofen; the amount of drug absorbed remains constant. However, plasma concentrations of ketoprofen after single- and multiple-dose administration were greatly affected by food, with a decrease of greater than 40 percent in bioavailability.