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Clinical Pharmacology

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 8).

Table 8: 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 9).

Table 9: Gastric Ulcer Healing Rates


  PREVACID Placebo
Week 15 mg daily (N=65) 30 mg daily (N=63) 60 mg daily (N=61) (N=64)
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 Independent substantiation of the effectiveness of PREVACID 30 mg was provided by a meta-analysis of published and unpublished data.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 10).

Table 10: NSAID-Associated Gastric Ulcer Healing Rates 1


Study #1
  PREVACID 30 mg daily Active Control 2
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 Control 2
Week 4 53% (40/75) 38% (31/82)
Week 8 77% (47/61) 3 50% (33/66)
Actual observed ulcer(s) healed at time points + 2 days
Dose for healing of gastric ulcer
(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 11).

Table 11: Proportion of Patients Remaining Free of Gastric Ulcers1


Week PREVACID15 mg daily
(N=121)
PREVACID 30 mg daily
(N=116)
Misoprostol 200 jig 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 12 and in Figures 1 and 2:

Table 12: 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)


Mean Severity of Day Heartburn By Study Day For Evaluable Patients - Illustration

 

Figure 2
Mean Severity of Night Heartburn By Study Day For Evaluable Patients (3=Severe, 2=Moderate, 1=Mild, 0=None)


Mean Severity of Night Heartburn By Study Day For Evaluable Patients - Illustration

 

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 (b.i.d.) 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.

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 13:

Table 13: Erosive Esophagitis Healing Rates


  PREVACID Placebo
Week 15 mg daily
(N=69)
30 mg daily
(N=65)
60 mg daily
(N=72)

(N=63)
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 b.i.d. as shown below (Table 14).

Table 14: Erosive Esophagitis Healing Rates


Week PREVACID30 mg daily
(N=115)
Ranitidine150 mg b.i.d.
(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 b.i.d.

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 b.i.d. 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 b.i.d. 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 15).

Table 15: Reflux Esophagitis Healing Rates in
Patients Poorly Responsive to Histamine H2-Receptor
Antagonist Therapy


Week PREVACID30 mg daily
(N=100)
Ranitidine150 mg b.i.d.
(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 16).

Table 16: Endoscopic Remission Rates


Trial Drug Percent in Endoscopic Remission
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 b.i.d. (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 thanthose 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.

Pathological Hypersecretory Conditions Including Zollinger-Ellison Syndrome

In open studies of 57 patients with pathological hypersecretory conditions, such as Zollinger-Ellison (ZE) syndrome 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 ZE 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.

Reference

1. National Committee for Clinical Laboratory Standards. Summary Minutes, Subcommittee on Antimicrobial Susceptibility Testing, Tampa, FL, January 11-13, 1998.

Brand Name: Zyrtec
Generic Name: Cetirizine
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