Pharmacokinetic interaction between acetaminophen and lansoprazole

Because of its minimal gastric toxicity, acetaminophen is the analgesic of choice for patients with gastric acid-related disorders. Because proton pum p inhibitors an widely used, concomitant prescription of acetaminophen and lansoprazole would be prevalent. This crossover study was conducted to inve stigate an acetaminophen-lansoprazole interaction. On one occasion, each of six healthy, fasted, male volunteers ingested 1.0 g acetaminophen dissolve d in 200 mt water. On another occasion. at least 1 week apart. 30 mg lansop razole was administered orally, simultaneously with acetaminophen, after pr etreatment with the same dose of lansoprazole once daily for 2 days. Plasma acetaminophen concentrations were measured at 0, 0.25, 0.5, 0.75, 1, 2, 3, 5, and 8 hours after dosing. The peak plasma concentration of acetaminophe n and the time to its occurrence were significantly higher and shorter, res pectively, during the lansoprazole session than during the control session. Neither the elimination half-life nor the area under the curve was signifi cantly different between the two sessions. Lansoprazole hastens the absorpt ion of acetaminophen solution, but little modifies its elimination rate and bioavailability.