Mechanism of Action
PREVACID (lansoprazole) belongs to a class of antisecretory compounds, the
substituted benzimidazoles, that suppress gastric acid secretion by specific
inhibition of the (H+, K+)-ATPase enzyme system at the
secretory surface of the gastric parietal cell. Because this enzyme system is
regarded as the acid (proton) pump within the parietal cell, lansoprazole has
been characterized as a gastric acid-pump inhibitor, in that it blocks the final
step of acid production. This effect is dose-related and leads to inhibition
of both basal and stimulated gastric acid secretion irrespective of the stimulus.
Lansoprazole does not exhibit anticholinergic or histamine type-2 antagonist
activity.
Pharmacodynamics
Antisecretory Activity: After oral administration, lansoprazole
was shown to significantly decrease the basal acid output and significantly
increase the mean gastric pH and percent of time the gastric pH was greater
than 3 and greater than 4. Lansoprazole also significantly reduced meal-stimulated
gastric acid output and secretion volume, as well as pentagastrin-stimulated
acid output. In patients with hypersecretion of acid, lansoprazole significantly
reduced basal and pentagastrin-stimulated gastric acid secretion. Lansoprazole
inhibited the normal increases in secretion volume, acidity and acid output
induced by insulin.
The intragastric pH results of a five-day, pharmacodynamic, crossover study
of 15 mg and 30 mg of once daily lansoprazole are presented in Table 4:
Table 4: Mean Antisecretory Effects After Single and Multiple
Daily PREVACID Dosing
| |
|
PREVACID |
| Parameter |
Baseline Value |
15 mg |
30mg |
| Day 1 |
Day 5 |
Day 1 |
Day 5 |
| Mean 24-Hour pH |
2.1 |
2.7+ |
4.0+ |
3.6* |
4.9* |
| Mean Nighttime pH |
1.9 |
2.4 |
3.0+ |
2.6 |
3.8* |
| % Time Gastric pH > 3 |
18 |
33+ |
59+ |
51* |
72* |
| % Time Gastric pH > 4 |
12 |
22+ |
49+ |
41* |
66* |
NOTE: An intragastric pH of greater than 4 reflects a reduction
in gastric acid by 99%.
*(p < 0.05) versus baseline and lansoprazole 15 mg.
+(p < 0.05) versus baseline only. |
After the initial dose in this study, increased gastric pH was seen within
1-2 hours with 30 mg of lansoprazole and 2-3 hours with 15 mg of lansoprazole.
After multiple daily dosing, increased gastric pH was seen within the first
hour post-dosing with 30 mg of lansoprazole and within 1-2 hours post-dosing
with 15 mg of lansoprazole.
Acid suppression may enhance the effect of antimicrobials in eradicating Helicobacter
pylori (H. pylori ). The percentage of time gastric pH was elevated
above 5 and 6 was evaluated in a crossover study of PREVACID given daily, twice
daily and three times daily (Table 5).
Table 5: Mean Antisecretory Effects After 5 Days of twice
daily and three times daily Dosing
| |
PREVACID |
| Parameter |
30 mg daily |
15 mg twice daily |
30 mg twice daily |
30 mg three times daily |
| % Time Gastric pH > 5 |
43 |
47 |
59+ |
77* |
| % Time Gastric pH > 6 |
20 |
23 |
28 |
45* |
+(p < 0.05) versus PREVACID 30 mg daily
*(p < 0.05) versus PREVACID 30 mg daily, 15 mg twice daily and 30 mg twice
daily. |
The inhibition of gastric acid secretion as measured by intragastric pH gradually returned to normal over two to four days after multiple doses. There was no indication of rebound gastric acidity.
Enterochromaffin-like (ECL) Cell Effects
During lifetime exposure of rats with up to 150 mg/kg/day of lansoprazole dosed
seven days per week, marked hypergastrinemia was observed followed by ECL cell
proliferation and formation of carcinoid tumors, especially in female rats.
Gastric biopsy specimens from the body of the stomach from approximately 150
patients treated continuously with lansoprazole for at least one year did not
show evidence of ECL cell effects similar to those seen in rat studies. Longer
term data are needed to rule out the possibility of an increased risk of the
development of gastric tumors in patients receiving long- term therapy with
lansoprazole. [See Nonclinical Toxicology]
Other Gastric Effects in Humans
Lansoprazole did not significantly affect mucosal blood flow in the fundus of the stomach. Due to the normal physiologic effect caused by the inhibition of gastric acid secretion, a decrease of about 17% in blood flow in the antrum, pylorus, and duodenal bulb was seen. Lansoprazole significantly slowed the gastric emptying of digestible solids. Lansoprazole increased serum pepsinogen levels and decreased pepsin activity under basal conditions and in response to meal stimulation or insulin injection. As with other agents that elevate intragastric pH, increases in gastric pH were associated with increases in nitrate-reducing bacteria and elevation of nitrite concentration in gastric juice in patients with gastric ulcer. No significant increase in nitrosamine concentrations was observed.
Serum Gastrin Effects
In over 2100 patients, median fasting serum gastrin levels increased 50% to 100% from baseline but remained within normal range after treatment with 15 to 60 mg of oral lansoprazole. These elevations reached a plateau within two months of therapy and returned to pretreatment levels within four weeks after discontinuation of therapy.
Endocrine Effects
Human studies for up to one year have not detected any clinically significant effects on the endocrine system. Hormones studied include testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), sex hormone binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEA-S), prolactin, cortisol, estradiol, insulin, aldosterone, parathormone, glucagon, thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and somatotropic hormone (STH). Lansoprazole in oral doses of 15 to 60 mg for up to one year had no clinically significant effect on sexual function. In addition, lansoprazole in oral doses of 15 to 60 mg for two to eight weeks had no clinically significant effect on thyroid function. In 24-month carcinogenicity studies in Sprague-Dawley rats with daily lansoprazole dosages up to 150 mg/kg, proliferative changes in the Leydig cells of the testes, including benign neoplasm, were increased compared to control rats.
Other Effects
No systemic effects of lansoprazole on the central nervous system, lymphoid,
hematopoietic, renal, hepatic, cardiovascular, or respiratory systems have been
found in humans. Among 56 patients who had extensive baseline eye evaluations,
no visual toxicity was observed after lansoprazole treatment (up to 180 mg/day)
for up to 58 months. After lifetime lansoprazole exposure in rats, focal pancreatic
atrophy, diffuse lymphoid hyperplasia in the thymus, and spontaneous retinal
atrophy were seen.
Microbiology
Lansoprazole, clarithromycin and/or amoxicillin have been shown to be active
against most strains of Helicobacter pylori in vitro and in clinical
infections as described in the INDICATIONS section. [See INDICATIONS]
Helicobacter pylori Pretreatment Resistance
Clarithromycin pretreatment resistance ( ≥ 2.0 µg/mL) was 9.5% (91/960) by E-test
and 11.3% (12/106) by agar dilution in the dual and triple therapy clinical
trials (M93-125, M93-130, M93-131, M95-392, and M95-399).
Amoxicillin pretreatment susceptible isolates (0.25 µg/mL) occurred in 97.8%
(936/957) and 98.0% (98/100) of the patients in the dual and triple therapy
clinical trials by E-test and agar dilution, respectively. Twenty-one of 957
patients (2.2%) by E-test and 2 of 100 patients (2.0%) by agar dilution had
amoxicillin pretreatment MICs of greater than 0.25 µg/mL. One patient on the
14-day triple therapy regimen had an unconfirmed pretreatment amoxicillin minimum
inhibitory concentration (MIC) of greater than 256 µg/mL by E-test and the patient
was eradicated of H. pylori (Table 6) .
Table 6: Clarithromycin Susceptibility Test Results and Clinical/Bacteriological
Outcomesa
| Clarithromycin Pretreatment Results |
Clarithromycin Post-treatment Results |
| |
H. pylori negative –eradicated |
H. pylori positive –not eradicated |
| |
|
Post-treatment susceptibility results |
| Sb |
Ib |
Rb |
No MIC |
Triple Therapy 14-Day (lansoprazole 30 mg twice daily/amoxicillin
1 gm twice daily/clarithromycin 500 mg twice daily)
(M95-399, M93-131, M95-392) |
| Susceptibleb |
112 |
105 |
|
|
|
7 |
| Intermediateb |
3 |
3 |
|
|
|
|
| Resistantb |
17 |
6 |
|
|
7 |
4 |
Triple Therapy 10-Day (lansoprazole 30 mg twice daily/amoxicillin
1 gm twice daily/clarithromycin 500 mg twice daily)
(M95-399) |
| Susceptibleb |
42 |
40 |
1 |
|
1 |
|
| Intermediateb |
|
|
|
|
|
|
| Resistantb |
4 |
1 |
|
|
3 |
|
a Includes only patients with pretreatment
clarithromycin susceptibility test results
b Susceptible (S) MIC ≤ 0.25 µg/mL, Intermediate (I) MIC
0.5 -1.0 µg/mL, Resistant (R) MIC ≥ 2 µg/mL |
Patients not eradicated of H. pylori following lansoprazole/amoxicillin/clarithromycin triple therapy will likely have clarithromycin resistant H. pylori. Therefore, for those patients who fail therapy, clarithromycin susceptibility testing should be done when possible. Patients with clarithromycin resistant H. pylori should not be treated with lansoprazole/amoxicillin/clarithromycin triple therapy or with regimens which include clarithromycin as the sole antimicrobial agent.
Amoxicillin Susceptibility Test Results and Clinical/Bacteriological
Outcomes: In the dual and triple therapy clinical trials, 82.6% (195/236)
of the patients that had pretreatment amoxicillin susceptible MICs (0.25 µg/mL)
were eradicated of H. pylori . Of those with pretreatment amoxicillin
MICs of greater than 0.25 µg/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 gm 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 x 107 – 1 x 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
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 (µg/mL)a |
Interpretation |
| ≤ 0.25 |
Susceptible (S) |
| 0.5-1.0 |
Intermediate (I) |
| ≥ 2.0 |
Resistant (R) |
| Amoxicillin MIC (µg/mL)b |
Interpretation |
| ≤ 0.25 |
Susceptible (S) |
a These are tentative breakpoints for the agar
dilution methodology and they should not be used to interpret results obtained
using alternative methods.
b There were not enough organisms with MICs greater than 0.25
µg/mL to determine a resistance breakpoint. |
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 (µg/mL) a |
| H. pylori ATCC 43504 |
Clarithromycin |
0.015-0.12 µg/mL |
| H. pylori ATCC 43504 |
Amoxicillin |
0.015-0.12 µg/mL |
| a These are quality control ranges
for the agar dilution methodology and they should not be used to control
test results obtained using alternative methods. |
Pharmacokinetics
PREVACID Delayed-Release Capsules, PREVACID SoluTab Delayed-Release Orally
Disintegrating Tablets and PREVACID for Delayed-Release Oral Suspension 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 C max occurring approximately 1.7 hours after oral dosing, and the absolute
bioavailability is over 80%. In healthy subjects, the mean (±SD) plasma half-life
was 1.5 (±1.0) hours. Both the Cmax and AUC are diminished by about 50% to 70%
if lansoprazole is given 30 minutes after food, compared to the fasting condition.
There is no significant food effect if lansoprazole is given before meals.
Distribution: Lansoprazole is 97% bound to plasma proteins. Plasma
protein binding is constant over the concentration range of 0.05 to 5.0 µg/mL.
Metabolism: Lansoprazole is extensively metabolized in the liver.
Two metabolites have been identified in measurable quantities in plasma (the
hydroxylated sulfinyl and sulfone derivatives of lansoprazole). These metabolites
have very little or no antisecretory activity. Lansoprazole is thought to be
transformed into two active species which inhibit acid secretion by blocking
the proton pump [(H+, K+)-ATPase enzyme system] at the
secretory surface of the gastric parietal cell. The two active species are not
present in the systemic circulation. The plasma elimination half-life of lansoprazole
is less than 2 hours while the acid inhibitory effect lasts more than 24 hours.
Therefore, the plasma elimination half-life of lansoprazole does not reflect
its duration of suppression of gastric acid secretion.
Elimination: Following single-dose oral administration of PREVACID,
virtually no unchanged lansoprazole was excreted in the urine. In one study,
after a single oral dose of 14C-lansoprazole, approximately one-third
of the administered radiation was excreted in the urine and two-thirds was recovered
in the feces. This implies a significant biliary excretion of the lansoprazole
metabolites.
Specific Populations
Pediatric Use
One to 17 years of age
The pharmacokinetics of lansoprazole were studied in pediatric patients with
GERD aged 1 to 11 years and 12 to 17 years in two separate clinical studies.
In children aged 1 to 11 years, lansoprazole was dosed 15 mg daily for subjects
weighing ≤ 30 kg and 30 mg daily for subjects weighing greater
than 30 kg. Mean Cmax and AUC values observed on Day 5 of dosing were similar
between the two dose groups and were not affected by weight or age within each
weight-adjusted dose group used in the study. In adolescent subjects aged 12
to 17 years, subjects were randomized to receive lansoprazole at 15 mg or 30
mg daily. Mean Cmax and AUC values of lansoprazole were not affected by body
weight or age; and nearly dose- proportional increases in mean Cmax and AUC
values were observed between the two dose groups in the study. Overall, lansoprazole
pharmacokinetics in pediatric patients aged 1 to 17 years were similar to those
observed in healthy adult subjects.
Neonate to less than one year of age
Refer to Section 8.4 for the pharmacokinetics of lansoprazole in pediatric patients with GERD aged less than 28 days and 1 to 11 months.
Geriatric Use: The clearance of lansoprazole is decreased in
the elderly, with elimination half-life increased approximately 50% to 100%.
Because the mean half-life in the elderly remains between 1.9 to 2.9 hours,
repeated once daily dosing does not result in accumulation of lansoprazole.
Peak plasma levels were not increased in the elderly. No dosage adjustment is
necessary in the elderly [See Use in Specific Populations].
Renal Impairment: In patients with severe renal impairment, plasma
protein binding decreased by 1.0%-1.5% after administration of 60 mg of lansoprazole.
Patients with renal impairment had a shortened elimination half-life and decreased
total AUC (free and bound). The AUC for free lansoprazole in plasma, however,
was not related to the degree of renal impairment; and the C max and t max (time
to reach the maximum concentration) were not different than the C max and t
max from subjects with normal renal function. No dosage adjustment is necessary
in patients with renal impairment [See Use in Specific
Populations] .
Hepatic Impairment: In patients with various degrees of chronic
hepatic impairment, the mean plasma half-life of lansoprazole was prolonged
from 1.5 hours to 3.2-7.2 hours. An increase in the mean AUC of up to 500% was
observed at steady state in hepatically-impaired patients compared to healthy
subjects. Consider dose reduction in patients with severe hepatic impairment
[See Use in Specific Populations].
Gender: In a study comparing 12 male and 6 female human subjects
who received lansoprazole, no gender differences were found in pharmacokinetics
and intragastric pH results [See Use in Specific
Populations] .
Drug-Drug Interactions
It is theoretically possible that PREVACID may interfere with the absorption of other drugs where gastric pH is an important determinant of bioavailability (e.g., ketoconazole, ampicillin esters, iron salts, digoxin).
PREVACID is metabolized through the cytochrome P 450 system, specifically through
the CYP3A and CYP2C19 isozymes. Studies have shown that PREVACID does not have
clinically significant interactions with other drugs metabolized by the cytochrome
P 450 system, such as warfarin, antipyrine, indomethacin, ibuprofen, phenytoin,
propranolol, prednisone, diazepam, or clarithromycin in healthy subjects. These
compounds are metabolized through various cytochrome P 450 isozymes including
CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A.
Atazanavir: PREVACID causes long-lasting inhibition of gastric
acid secretion. PREVACID substantially decreases the systemic concentrations
of the HIV protease inhibitor atazanavir, which is dependent upon the presence
of gastric acid for absorption, and may result in a loss of therapeutic effect
of atazanavir and the development of HIV resistance. Therefore, PREVACID, or
other proton pump inhibitors, should not be co-administered with atazanavir.
Theophylline: When PREVACID was administered concomitantly with
theophylline (CYP1A2, CYP3A), a minor increase (10%) in the clearance of theophylline
was seen. Because of the small magnitude and the direction of the effect on
theophylline clearance, this interaction is unlikely to be of clinical concern.
Nonetheless, individual patients may require additional titration of their theophylline
dosage when PREVACID is started or stopped to ensure clinically effective blood
levels.
Warfarin: In a study of healthy subjects neither the pharmacokinetics
of warfarin enantiomers nor prothrombin time were affected following single
or multiple 60 mg doses of lansoprazole. However, there have been reports of
increased International Normalized Ratio (INR) and prothrombin time in patients
receiving proton pump inhibitors, including PREVACID, and warfarin concomitantly.
Increases in INR and prothrombin time may lead to abnormal bleeding and even
death. Patients treated with proton pump inhibitors and warfarin concomitantly
may need to be monitored for increases in INR and prothrombin time.
Methotrexate and 7-hydromethotrexate: In an open-label, single-arm,
eight-day, pharmacokinetic study of 28 adult rheumatoid arthritis patients (who
required the chronic use of 7.5 to 15 mg of methotrexate given weekly), administration
of 7 days of naproxen 500 mg twice daily and PREVACID 30 mg daily had no effect
on the pharmacokinetics of methotrexate and 7-hydroxymethotrexate. While this
study was not designed to assess the safety of this combination of drugs, no
major adverse reactions were noted.
Amoxicillin: PREVACID has also been shown to have no clinically
significant interaction with amoxicillin.
Sucralfate: In a single-dose crossover study examining PREVACID
30 mg and omeprazole 20 mg each administered alone and concomitantly with sucralfate
1 gram, absorption of the proton pump inhibitors was delayed and their bioavailability
was reduced by 17% and 16%, respectively, when administered concomitantly with
sucralfate. Therefore, proton pump inhibitors should be taken at least 30 minutes
prior to sucralfate. In clinical trials, antacids were administered concomitantly
with PREVACID and there was no evidence of a change in the efficacy of PREVACID.
Clinical Studies
Duodenal Ulcer
In a U.S. multicenter, double-blind, placebo-controlled, dose-response (15,
30, and 60 mg of PREVACID once daily) study of 284 patients with endoscopically
documented duodenal ulcer, the percentage of patients healed after two and four
weeks was significantly higher with all doses of PREVACID than with placebo.
There was no evidence of a greater or earlier response with the two higher doses
compared with PREVACID 15 mg. Based on this study and the second study described
below, the recommended dose of PREVACID in duodenal ulcer is 15 mg per day (Table
9).
Table 9: Duodenal Ulcer Healing Rates
| |
PREVACID |
Placebo
(N=72) |
| Week |
15 mg daily
(N=68) |
30 mg daily
(N=74) |
60 mg daily
(N=70) |
| 2 |
42.4%* |
35.6%* |
39.1%* |
11.3% |
| 4 |
89.4%* |
91.7%* |
89.9%* |
46.1% |
| * (p ≤ 0.001) versus placebo. |
PREVACID 15 mg was significantly more effective than placebo in relieving day and nighttime abdominal pain and in decreasing the amount of antacid taken per day.
In a second U.S. multicenter study, also double-blind, placebo-controlled,
dose-comparison (15 and 30 mg of PREVACID once daily), and including a comparison
with ranitidine, in 280 patients with endoscopically documented duodenal ulcer,
the percentage of patients healed after four weeks was significantly higher
with both doses of PREVACID than with placebo. There was no evidence of a greater
or earlier response with the higher dose of PREVACID. Although the 15 mg dose
of PREVACID was superior to ranitidine at 4 weeks, the lack of significant difference
at 2 weeks and the absence of a difference between 30 mg of PREVACID and ranitidine
leaves the comparative effectiveness of the two agents undetermined (Table 10).
[See INDICATIONS]
Table 10: Duodenal Ulcer Healing Rates
| |
PREVACID |
Ranitidine |
Placebo
(N=41) |
| Week |
15 mg daily
(N=80) |
30 mg daily
(N=77) |
300 mg h.s.
(N=82) |
| 2 |
35.0% |
44.2% |
30.5% |
34.2% |
| 4 |
92.3%** |
80.3%* |
70.5%* |
47.5% |
*(p ≤ 0.05) versus placebo.
**(p ≤ 0.05) versus placebo and ranitidine. |
H. pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence
Randomized, double-blind clinical studies performed in the U.S. in patients with H. pylori and duodenal ulcer disease (defined as an active ulcer or history of an ulcer within one year) evaluated the efficacy of PREVACID in combination with amoxicillin capsules and clarithromycin tablets as triple 14 day therapy or in combination with amoxicillin capsules as dual 14-day therapy for the eradication of H. pylori. Based on the results of these studies, the safety and efficacy of two different eradication regimens were established:
Triple therapy: PREVACID 30 mg twice daily/amoxicillin 1 gm twice daily/clarithromycin
500 mg twice daily
Dual therapy: PREVACID 30 mg three times daily/amoxicillin 1 gm three
times daily
All treatments were for 14 days. H. pylori eradication was defined as two negative tests (culture and histology) at 4-6 weeks following the end of treatment.
Triple therapy was shown to be more effective than all possible dual therapy combinations. Dual therapy was shown to be more effective than both monotherapies. Eradication of H. pylori has been shown to reduce the risk of duodenal ulcer recurrence.
A randomized, double-blind clinical study performed in the U.S. in patients
with H. pylori and duodenal ulcer disease (defined as an active ulcer
or history of an ulcer within one year) compared the efficacy of PREVACID triple
therapy for 10 and 14 days. This study established that the 10-day triple therapy
was equivalent to the 14-day triple therapy in eradicating H. pylori
(Tables 11 and 12) . [See INDICATIONS]
Table 11: H. pylori Eradication Rates Triple Therapy
(PREVACID/amoxicillin/clarithromycin) Percent of Patients Cured [95% Confidence
Interval] (Number of patients)
| Study |
Duration |
Triple Therapy Evaluable Analysis* |
Triple Therapy Intent-to-Treat Analysis # |
| M93-131 |
14 days |
92†
[80.0-97.7]
(N=48) |
86†
[73.3-93.5]
(N=55) |
| M95-392 |
14 days |
86‡
[75.7-93.6]
(N=66) |
83‡
[72.0-90.8]
(N=70) |
| M95-399+ |
14 days |
85
[77.0-91.0]
(N=113) |
82
[73.9-88.1]
(N=126) |
| 10 days |
84
[76.0-89.8]
(N=123) |
81
[73.9-87.6]
(N=135) |
*Based on evaluable patients with confirmed duodenal ulcer
(active or within one year) and H. pylori infection at baseline defined
as at least two of three positive endoscopic tests from CLOtest® , histology
and/or culture. Patients were included in the analysis if they completed
the study. Additionally, if patients dropped out of the study due to an
adverse event related to the study drug, they were included in the evaluable
analysis as failures of therapy.
#Patients were included in the analysis if they had documented
H. pylori infection at baseline as defined above and had a confirmed
duodenal ulcer (active or within one year). All dropouts were included as
failures of therapy.
†(p < 0.05) versus PREVACID/amoxicillin and PREVACID/clarithromycin dual
therapy.
‡(p < 0.05) versus clarithromycin/amoxicillin dual therapy.
+The 95% confidence interval for the difference in eradication
rates, 10-day minus 14-day is (-10.5, 8.1) in the evaluable analysis and
(-9.7, 9.1) in intent-to-treat analysis. |
Table 12: H. pylori Eradication Rates – 14-Day Dual
Therapy (PREVACID/amoxicillin) Percent of Patients Cured [95% Confidence Interval]
(Number of patients)
| Study |
Dual Therapy Evaluable Analysis * |
Dual Therapy Intent-to-Treat Analysis
# |
| M93-131 |
77†
[62.5-87.2]
(N=51) |
70†
[56.8-81.2]
(N=60) |
| M93-125 |
66‡
[51.9-77.5]
(N=58) |
61‡
[48.5-72.9]
(N=67) |
*Based on evaluable patients with confirmed duodenal ulcer
(active or within one year) and H. pylori infection at baseline defined
as at least two of three positive endoscopic tests from CLOtest® , histology
and/or culture. Patients were included in the analysis if they completed
the study. Additionally, if patients dropped out of the study due to an
adverse event related to the study drug, they were included in the analysis
as failures of therapy.
# Patients were included in the analysis if they had documented
H. pylori infection at baseline as defined above and had a confirmed
duodenal ulcer (active or within one year). All dropouts were included as
failures of therapy.
† (p < 0.05) versus PREVACID alone.
‡(p < 0.05) versus PREVACID alone or amoxicillin alone. |
Long-Term Maintenance Treatment of Duodenal Ulcers
PREVACID has been shown to prevent the recurrence of duodenal ulcers. Two independent,
double-blind, multicenter, controlled trials were conducted in patients with
endoscopically confirmed healed duodenal ulcers. Patients remained healed significantly
longer and the number of recurrences of duodenal ulcers was significantly less
in patients treated with PREVACID than in patients treated with placebo over
a 12-month period (Table 13). [See INDICATIONS]
Table 13: Endoscopic Remission Rates
| Trial |
Drug |
No. of Pts. |
Percent in Endoscopic Remission |
| 0-3 mo. |
0-6 mo. |
0-12 mo. |
| #1 |
PREVACID 15 mg daily |
86 |
90%* |
87%* |
84%* |
| Placebo |
83 |
49% |
41% |
39% |
| #2 |
PREVACID 30 mg daily |
18 |
94%* |
94%* |
85%* |
| PREVACID 15 mg daily |
15 |
87%* |
79%* |
70%* |
| Placebo |
15 |
33% |
0% |
0% |
%= Life Table Estimate
*(p ≤ 0.001) versus placebo. |
In trial #2, no significant difference was noted between PREVACID 15 mg and 30 mg in maintaining remission.
Gastric Ulcer
In a U.S. multicenter, double-blind, placebo-controlled study of 253 patients
with endoscopically documented gastric ulcer, the percentage of patients healed
at four and eight weeks was significantly higher with PREVACID 15 mg and 30
mg once a day than with placebo (Table 14). [See INDICATIONS]
Table 14: Gastric Ulcer Healing Rates
| |
PREVACID |
Placebo
(N=64) |
| Week |
15 mg daily
(N=65) |
30 mg daily
(N=63) |
60 mg daily
(N=61) |
| 4 |
64.6%* |
58.1%* |
53.3%* |
37.5% |
| 8 |
92.2%* |
96.8%* |
93.2%* |
76.7% |
| * (p ≤ 0.05) versus placebo. |
Patients treated with any PREVACID dose reported significantly less day and
night abdominal pain along with fewer days of antacid use and fewer antacid
tablets used per day than the placebo group.
Independent substantiation of the effectiveness of PREVACID 30 mg was provided
by a meta-analysis of published and unpublished data.
Healing of NSAID-Associated Gastric Ulcer
In two U.S. and Canadian multicenter, double-blind, active-controlled studies
in patients with endoscopically confirmed NSAID-associated gastric ulcer who
continued their NSAID use, the percentage of patients healed after 8 weeks was
statistically significantly higher with 30 mg of PREVACID than with the active
control. A total of 711 patients were enrolled in the study, and 701 patients
were treated. Patients ranged in age from 18 to 88 years (median age 59 years),
with 67% female patients and 33% male patients. Race was distributed as follows:
87% Caucasian, 8% Black, 5% Other. There was no statistically significant difference
between PREVACID 30 mg daily and the active control on symptom relief (i.e.,
abdominal pain) (Table 15). [See INDICATIONS]
Table 15: NSAID-Associated Gastric Ulcer Healing Rates1
| Study #1 |
| |
PREVACID
30 mg daily |
Active Control2 |
| Week 4 |
60% (53/88)3 |
28% (23/83) |
| Week 8 |
79% (62/79)3 |
55% (41/74) |
| Study #2 |
| |
PREVACID
30 mg daily |
Active Control2 |
| Week 4 |
53% (40/75) |
38% (31/82) |
| Week 8 |
77% (47/61)3 |
50% (33/66) |
1 Actual observed ulcer(s) healed at time points
± 2 days
2 Dose for healing of gastric ulcer
3 (p ≤ 0.05) versus the active control |
Risk Reduction of NSAID-Associated Gastric Ulcer
In one large U.S., multicenter, double-blind, placebo-and misoprostol-controlled
(misoprostol blinded only to the endoscopist) study in patients who required
chronic use of an NSAID and who had a history of an endoscopically documented
gastric ulcer, the proportion of patients remaining free from gastric ulcer
at 4, 8, and 12 weeks was significantly higher with 15 or 30 mg of PREVACID
than placebo. A total of 537 patients were enrolled in the study, and 535 patients
were treated. Patients ranged in age from 23 to 89 years (median age 60 years),
with 65% female patients and 35% male patients. Race was distributed as follows:
90% Caucasian, 6% Black, 4% other. The 30 mg dose of PREVACID demonstrated no
additional benefit in risk reduction of the NSAID-associated gastric ulcer than
the 15 mg dose (Table 16). [See INDICATIONS]
Table 16: Proportion of Patients Remaining Free of Gastric
Ulcers 1
| Week |
PREVACID
15 mg daily
(N=121) |
PREVACID
30 mg daily
(N=116) |
Misoprosto
l200 µg q.i.d.
(N=106) |
Placebo
(N=112) |
| 4 |
90% |
92% |
96% |
66% |
| 8 |
86% |
88% |
95% |
60% |
| 12 |
80% |
82% |
93% |
51% |
1 % = Life Table Estimate
(p < 0.001) PREVACID 15 mg daily versus placebo; PREVACID 30 mg daily versus
placebo; and misoprostol 200 µg q.i.d. versus placebo.
(p < 0.05) Misoprostol 200 µg q.i.d. versus PREVACID 15 mg daily; and misoprostol
200 µg q.i.d. versus PREVACID 30 mg daily. |
Gastroesophageal Reflux Disease (GERD)
Symptomatic GERD: In a U.S. multicenter, double-blind, placebo-controlled
study of 214 patients with frequent GERD symptoms, but no esophageal erosions
by endoscopy, significantly greater relief of heartburn associated with GERD
was observed with the administration of lansoprazole 15 mg once daily up to
8 weeks than with placebo. No significant additional benefit from lansoprazole
30 mg once daily was observed.
The intent-to-treat analyses demonstrated significant reduction in frequency and severity of day and night heartburn. Data for frequency and severity for the 8-week treatment period are presented in Table 17 and in Figures 1 and 2:
Table 17: Frequency of Heartburn
| Variable |
Placebo
(n=43) |
PREVACID 15 mg
(n=80) |
PREVACID 30 mg
(n=86) |
| Median |
| % of Days without Heartburn |
| Week 1 |
0% |
71%* |
46%* |
| Week 4 |
11% |
81%* |
76%* |
| Week 8 |
13% |
84%* |
82%* |
| % of Nights without Heartburn |
| Week 1 |
17% |
86%* |
57%* |
| Week 4 |
25% |
89%* |
73%* |
| Week 8 |
36% |
92%* |
80%* |
| *(p < 0.01) versus placebo. |
Figure: 1 Mean Severity of Day Heartburn By Study Day For
Evaluable Patients (3 = Severe, 2 Moderate, 1 = Mild, 0 = None)
Figure: 2 Mean Severity of Night Heartburn By Study Day For
Evaluable Patients (3 = Severe, 2 Moderate, 1 = Mild, 0 = None)
In two U.S., multicenter double-blind, ranitidine-controlled studies of 925
total patients with frequent GERD symptoms, but no esophageal erosions by endoscopy,
lansoprazole 15 mg was superior to ranitidine 150 mg (twice daily) in decreasing
the frequency and severity of day and night heartburn associated with GERD for
the 8-week treatment period. No significant additional benefit from lansoprazole
30 mg once daily was observed. [See INDICATIONS]
Erosive Esophagitis
In a U.S. multicenter, double-blind, placebo-controlled study of 269 patients entering with an endoscopic diagnosis of esophagitis with mucosal grading of 2 or more and grades 3 and 4 signifying erosive disease, the percentages of patients with healing are presented in Table 18:
Table 18: Erosive Esophagitis Healing Rates
| |
PREVACID |
Placebo
(N=63) |
| Week |
15 mg daily
(N=69) |
30 mg daily
(N=65) |
60 mg daily
(N=72) |
| 4 |
67.6%* |
81.3% *† |
80.6%*† |
32.8% |
| 6 |
87.7%* |
95.4%* |
94.3%* |
52.5% |
| 8 |
90.9%* |
95.4%* |
94.4%* |
52.5% |
* (p 0.001) versus placebo.
†(p 0.05) versus PREVACID 15 mg. |
In this study, all PREVACID groups reported significantly greater relief of
heartburn and less day and night abdominal pain along with fewer days of antacid
use and fewer antacid tablets taken per day than the placebo group.
Although all doses were effective, the earlier healing in the higher two doses suggests 30 mg daily as the recommended dose.
PREVACID was also compared in a U.S. multicenter, double-blind study to a low
dose of ranitidine in 242 patients with erosive reflux esophagitis. PREVACID
at a dose of 30 mg was significantly more effective than ranitidine 150 mg twice
daily as shown below (Table 19).
Table 19: Erosive Esophagitis Healing Rates
| Week |
PREVACID
30 mg daily
(N=115) |
Ranitidine
150 mg twice daily
(N=127) |
| 2 |
66.7%* |
38.7% |
| 4 |
82.5%* |
52.0% |
| 6 |
93.0%* |
67.8% |
| 8 |
92.1%* |
69.9% |
| *(p ≤ 0.001) versus ranitidine. |
In addition, patients treated with PREVACID reported less day and nighttime
heartburn and took less antacid tablets for fewer days than patients taking
ranitidine 150 mg twice daily.
Although this study demonstrates effectiveness of PREVACID in healing erosive esophagitis, it does not represent an adequate comparison with ranitidine because the recommended ranitidine dose for esophagitis is 150 mg q.i.d., twice the dose used in this study.
In the two trials described and in several smaller studies involving patients with moderate to severe erosive esophagitis, PREVACID produced healing rates similar to those shown above.
In a U.S. multicenter, double-blind, active-controlled study, 30 mg of PREVACID
was compared with ranitidine 150 mg twice daily in 151 patients with erosive
reflux esophagitis that was poorly responsive to a minimum of 12 weeks of treatment
with at least one H2-receptor antagonist given at the dose indicated
for symptom relief or greater, namely, cimetidine 800 mg/day, ranitidine 300
mg/day, famotidine 40 mg/day or nizatidine 300 mg/day.
PREVACID 30 mg was more effective than ranitidine 150 mg twice daily in healing
reflux esophagitis, and the percentage of patients with healing were as follows.
This study does not constitute a comparison of the effectiveness of histamine
H2-receptor antagonists with PREVACID, as all patients had demonstrated
unresponsiveness to the histamine H2-receptor antagonist mode of
treatment. It does indicate, however, that PREVACID may be useful in patients
failing on a histamine H2-receptor antagonist (Table 20). [See INDICATIONS]
Table 20: Reflux Esophagitis Healing Rates in Patients Poorly
Responsive to Histamine H2-Receptor Antagonist Therapy
| Week |
PREVACID
30 mg daily
(N=100) |
Ranitidine
150 mg twice daily
(N=51) |
| 4 |
74.7%* |
42.6% |
| 8 |
83.7%* |
32.0% |
| *(p 0.001) versus ranitidine. |
Long-Term Maintenance Treatment of Erosive Esophagitis
Two independent, double-blind, multicenter, controlled trials were conducted in patients with endoscopically confirmed healed esophagitis. Patients remained in remission significantly longer and the number of recurrences of erosive esophagitis was significantly less in patients treated with PREVACID than in patients treated with placebo over a 12-month period (Table 21).
Table 21: Endoscopic Remission Rates
| |
|
|
Percent in Endoscopic Remission |
| Trial |
Drug |
No. of Pts. |
0-3 mo. |
0-6 mo. |
0-12 mo. |
| #1 |
PREVACID 15 mg daily |
59 |
83%* |
81%* |
79%* |
| PREVACID 30 mg daily |
56 |
93%* |
93%* |
90%* |
| Placebo |
55 |
31% |
27% |
24% |
| #2 |
PREVACID 15 mg daily |
50 |
74%* |
72%* |
67%* |
| PREVACID 30 mg daily |
49 |
75%* |
72%* |
55%* |
| Placebo |
47 |
16% |
13% |
13% |
%=Life Table Estimate
*(p 0.001) versus placebo. |
Regardless of initial grade of erosive esophagitis, PREVACID 15 mg and 30 mg were similar in maintaining remission.
In a U.S., randomized, double-blind, study, PREVACID 15 mg daily (n = 100)
was compared with ranitidine 150 mg twice daily (n = 106), at the recommended
dosage, in patients with endoscopically-proven healed erosive esophagitis over
a 12-month period. Treatment with PREVACID resulted in patients remaining healed
(Grade 0 lesions) of erosive esophagitis for significantly longer periods of
time than those treated with ranitidine (p < 0.001). In addition, PREVACID
was significantly more effective than ranitidine in providing complete relief
of both daytime and nighttime heartburn. Patients treated with PREVACID remained
asymptomatic for a significantly longer period of time than patients treated
with ranitidine. [See INDICATIONS]
Pathological Hypersecretory Conditions Including Zollinger-Ellison Syndrome
In open studies of 57 patients with pathological hypersecretory conditions, such as Zollinger-Ellison syndrome (ZES) with or without multiple endocrine adenomas, PREVACID significantly inhibited gastric acid secretion and controlled associated symptoms of diarrhea, anorexia and pain. Doses ranging from 15 mg every other day to 180 mg per day maintained basal acid secretion below 10 mEq/hr in patients without prior gastric surgery and below 5 mEq/hr in patients with prior gastric surgery.
Initial doses were titrated to the individual patient need, and adjustments
were necessary with time in some patients. [See DOSAGE
AND ADMINISTRATION] PREVACID was well tolerated at these high dose levels
for prolonged periods (greater than four years in some patients). In most ZES
patients, serum gastrin levels were not modified by PREVACID. However, in some
patients, serum gastrin increased to levels greater than those present prior
to initiation of lansoprazole therapy. [See INDICATIONS]
REFERENCE
1 National Committee for Clinical Laboratory Standards. Summary
Minutes, Subcommittee on Antimicrobial Susceptibility Testing, Tampa, FL, January
11-13, 1998.
Last updated on RxList: 1/8/2009