PREVACID SoluTab (lansoprazole) Delayed-Release Orally Disintegrating Tablets (十七)
in susceptible MICs (≤0.25 mcg/mL) were eradicated of H. pylori. Of those with pretreatment amoxicillin MICs of greater than 0.25 mcg/mL, three of six had the H. pylori eradicated. A total of 30% (21/70) of the patients failed lansoprazole 30 mg three times daily/amoxicillin 1 g three times daily dual therapy and a total of 12.8% (22/172) of the patients failed the 10- and 14-day triple therapy regimens. Post-treatment susceptibility results were not obtained on 11 of the patients who failed therapy. Nine of the 11 patients with amoxicillin post-treatment MICs that failed the triple therapy regimen also had clarithromycin resistant H. pylori isolates.
Susceptibility Test for Helicobacter pylori: The reference methodology for susceptibility testing of H. pylori is agar dilution MICs.1 One to three microliters of an inoculum equivalent to a No. 2 McFarland standard (1 × 107 to 1 × 108 CFU/mL for H. pylori) are inoculated directly onto freshly prepared antimicrobial-containing Mueller-Hinton agar plates with 5% aged defibrinated sheep blood (≥2 weeks old). The agar dilution plates are incubated at 35°C in a microaerobic environment produced by a gas generating system suitable for campylobacters.
After 3 days of incubation, the MICs are recorded as the lowest concentration of antimicrobial agent required to inhibit growth of the organism. The clarithromycin and amoxicillin MIC values should be interpreted according to the following criteria (Table 7):
Table 7 Clarithromycin MIC
(mcg/mL)* Interpretation
* These are tentative breakpoints for the agar dilution methodology and they should not be used to interpret results obtained using alternative methods. † There were not enough organisms with MICs greater than 0.25 mcg/mL to determine a resistance breakpoint.
≤0.25 Susceptible (S)
0.5-1.0 Intermediate (I)
≥2.0 Resistant (R)
Amoxicillin MIC
(mcg/mL)*,† Interpretation
≤0.25 Susceptible (S)
Standardized susceptibility test procedures require the use of laboratory control microorganisms to control the technical aspects of the laboratory procedures. Standard clarithromycin and amoxicillin powders should provide the following MIC values (Table 8):
Table 8 Microorganism Antimicrobial Agent MIC (mcg/mL)*
* These are quality control ranges for the agar dilution methodology and they should not be used to control test results obtained using alternative methods.
H. pylori ATCC 43504 Clarithromycin 0.015-0.12
H. pylori ATCC 43504 Amoxicillin 0.015-0.12
12.3 PharmacokineticsPREVACID Delayed-Release Capsules and PREVACID SoluTab Delayed-Release Orally Disintegrating Tablets contain an enteric-coated granule formulation of lansoprazole. Absorption of lansoprazole begins only after the granules leave the stomach. Absorption is rapid, with mean peak plasma levels of lansoprazole occurring after approximately 1.7 hours. After a single-dose administration of 15 mg to 60 mg of oral lansoprazole, the peak plasma concentrations (Cmax) of lansoprazole and the area under the plasma concentration curves (AUCs) of lansoprazole were approximately proportional to the administered dose. Lansoprazole does not accumulate and its pharmacokinetics are unaltered by multiple dosing.
Absorption: The absorption of lansoprazole is rapid, with the mean Cmax occurring approximately 1.7 hours after oral dosing, and the absolute bioavailability |
