Lansoprazole pharmacokinetics differ in patients with oesophagitis compared to healthy volunteers

To compare the pharmacokinetics of lansoprazole in patients with reflux oesophagitis and in healthy volunteers, after a single dose and at steady-state.

A 30 mg dose of lansoprazole was administered orally daily for 7 days in eight healthy male volunteers aged 21-24 years, and in 16 patients aged 29-65 years with grade 2 or 3 reflux oesophagitis. The pharmacokinetics were assessed over the 24 h dose interval following the first dose and again after the 7th dose.

Within both the patient and volunteers groups, there were no significant differences between day 1 and day 7 in any of the pharmacokinetic parameters including maximum concentration (Cmax), area under the concentration-time curve (AUC), and terminal half-life of elimination (t(1/2)). However, on both days 1 and 7, values were significantly higher in the patients than in the healthy volunteers. On day 7, Cmax was 1343 ng/mL in patients compared with 765 ng/mL in healthy volunteers, AUC was 3458 ng.h/mL vs. 1350 ng.h/mL and t(1/2) was 1.62 h vs. 0.90 h.

The differences in results for the pharmacokinetics reflect reduced lansoprazole clearance in the patient group. Other research has not found a difference in pharmacokinetics when comparing healthy volunteers with patients with acid-related disorders. The difference in lansoprazole clearance in this study may be related to a variety of factors that are different in patients compared with young normal volunteers, such as age, gender, other drugs, and reduced general well-being.