Pepcid Injection

Name: Pepcid Injection

Indications

PEPCID Injection (famotidine injection) Premixed, supplied as a premixed solution in plastic containers (PL 2501 Plastic), and PEPCID Injection (famotidine injection) , supplied as a concentrated solution for intravenous injection, are intended for intravenous use only. PEPCID Injection (famotidine injection) Premixed and PEPCID Injection (famotidine injection) are indicated in some hospitalized patients with pathological hypersecretory conditions or intractable ulcers, or as an alternative to the oral dosage forms for short term use in patients who are unable to take oral medication for the following conditions:

  1. Short term treatment of active duodenal ulcer. Most adult patients heal within 4 weeks; there is rarely reason to use PEPCID at full dosage for longer than 6 to 8 weeks. Studies have not assessed the safety of famotidine in uncomplicated active duodenal ulcer for periods of more than eight weeks.
  2. Maintenance therapy for duodenal ulcer patients at reduced dosage after healing of an active ulcer. Controlled studies in adults have not extended beyond one year.
  3. Short term treatment of active benign gastric ulcer. Most adult patients heal within 6 weeks. Studies have not assessed the safety or efficacy of famotidine in uncomplicated active benign gastric ulcer for periods of more than 8 weeks.
  4. Short term treatment of gastroesophageal reflux disease (GERD). PEPCID is indicated for short term treatment of patients with symptoms of GERD (see CLINICAL PHARMACOLOGY IN ADULTS, Clinical Studies).
    PEPCID is also indicated for the short term treatment of esophagitis due to GERD including erosive or ulcerative disease diagnosed by endoscopy (see CLINICAL PHARMACOLOGY IN ADULTS, Clinical Studies).
  5. Treatment of pathological hypersecretory conditions (e.g., Zollinger-Ellison Syndrome, multiple endocrine adenomas) (see CLINICAL PHARMACOLOGY IN ADULTS, Clinical Studies).

Warnings

No information provided.

Clinical pharmacology

IN ADULTS

GI Effects

PEPCID is a competitive inhibitor of histamine H2-receptors. The primary clinically important pharmacologic activity of PEPCID is inhibition of gastric secretion. Both the acid concentration and volume of gastric secretion are suppressed by PEPCID, while changes in pepsin secretion are proportional to volume output.

In normal volunteers and hypersecretors, PEPCID inhibited basal and nocturnal gastric secretion, as well as secretion stimulated by food and pentagastrin. After oral administration, the onset of the antisecretory effect occurred within one hour; the maximum effect was dose-dependent, occurring within one to three hours. Duration of inhibition of secretion by doses of 20 and 40 mg was 10 to 12 hours.

After intravenous administration, the maximum effect was achieved within 30 minutes. Single intravenous doses of 10 and 20 mg inhibited nocturnal secretion for a period of 10 to 12 hours. The 20 mg dose was associated with the longest duration of action in most subjects.

Single evening oral doses of 20 and 40 mg inhibited basal and nocturnal acid secretion in all subjects; mean nocturnal gastric acid secretion was inhibited by 86% and 94%, respectively, for a period of at least 10 hours. The same doses given in the morning suppressed food-stimulated acid secretion in all subjects. The mean suppression was 76% and 84%, respectively, 3 to 5 hours after administration, and 25% and 30%, respectively, 8 to 10 hours after administration. In some subjects who received the 20 mg dose, however, the antisecretory effect was dissipated within 6-8 hours. There was no cumulative effect with repeated doses. The nocturnal intragastric pH was raised by evening doses of 20 and 40 mg of PEPCID to mean values of 5.0 and 6.4, respectively. When PEPCID was given after breakfast, the basal daytime interdigestive pH at 3 and 8 hours after 20 or 40 mg of PEPCID was raised to about 5.

PEPCID had little or no effect on fasting or postprandial serum gastrin levels. Gastric emptying and exocrine pancreatic function were not affected by PEPCID.

Other Effects

Systemic effects of PEPCID in the CNS, cardiovascular, respiratory or endocrine systems were not noted in clinical pharmacology studies. Also, no antiandrogenic effects were noted. (See ADVERSE REACTIONS.) Serum hormone levels, including prolactin, cortisol, thyroxine (T4), and testosterone, were not altered after treatment with PEPCID. Pharmacokinetics

Orally administered PEPCID is incompletely absorbed and its bioavailability is 40-45%. PEPCID undergoes minimal first-pass metabolism. After oral doses, peak plasma levels occur in 1-3 hours. Plasma levels after multiple doses are similar to those after single doses. Fifteen to 20% of PEPCID in plasma is protein bound. PEPCID has an elimination half-life of 2.5-3.5 hours. PEPCID is eliminated by renal (65-70%) and metabolic (30-35%) routes. Renal clearance is 250-450 mL/min, indicating some tubular excretion. Twenty-five to 30% of an oral dose and 65-70% of an intravenous dose are recovered in the urine as unchanged compound. The only metabolite identified in man is the S-oxide.

There is a close relationship between creatinine clearance values and the elimination half-life of PEPCID. In patients with severe renal insufficiency, i.e., creatinine clearance less than 10 mL/min, the elimination half-life of PEPCID may exceed 20 hours and adjustment of dose or dosing intervals in moderate and severe renal insufficiency may be necessary (see PRECAUTIONS, DOSAGE AND ADMINISTRATION).

In elderly patients, there are no clinically significant age-related changes in the pharmacokinetics of PEPCID. However, in elderly patients with decreased renal function, the clearance of the drug may be decreased (see PRECAUTIONS, Geriatric Use).

Clinical Studies

The majority of clinical study experience involved oral administration of PEPCID Tablets, and is provided herein for reference.

Duodenal Ulcer

In a U.S. multicenter, double-blind study in outpatients with endoscopically confirmed duodenal ulcer, orally administered PEPCID was compared to placebo. As shown in Table 1, 70% of patients treated with PEPCID 40 mg h.s. were healed by week 4.

Table 1
Outpatients with Endoscopically Confirmed Healed Duodenal Ulcers


  PEPCID
40 mg h.s.
(N=89)
PEPCID
20 mg b.i.d.
(N=84)
Placebo
h.s.
(N=97)
Week 2 ** 32% ** 38% 17%
Week 4 ** 70% ** 67% 31%
** Statistically significantly different than placebo (p < 0.001)

Patients not healed by week 4 were continued in the study. By week 8, 83% of patients treated with PEPCID had healed versus 45% of patients treated with placebo. The incidence of ulcer healing with PEPCID was significantly higher than with placebo at each time point based on proportion of endoscopically confirmed healed ulcers.

In this study, time to relief of daytime and nocturnal pain was significantly shorter for patients receiving PEPCID than for patients receiving placebo; patients receiving PEPCID also took less antacid than the patients receiving placebo.

Long-Term Maintenance Treatment of Duodenal Ulcers

PEPCID, 20 mg p.o. h.s. was compared to placebo h.s. as maintenance therapy in two double-blind, multicenter studies of patients with endoscopically confirmed healed duodenal ulcers. In the U.S. study the observed ulcer incidence within 12 months in patients treated with placebo was 2.4 times greater than in the patients treated with PEPCID. The 89 patients treated with PEPCID had a cumulative observed ulcer incidence of 23.4% compared to an observed ulcer incidence of 56.6% in the 89 patients receiving placebo (p < 0.01). These results were confirmed in an international study where the cumulative observed ulcer incidence within 12 months in the 307 patients treated with PEPCID was 35.7%, compared to an incidence of 75.5% in the 325 patients treated with placebo (p < 0.01).

Gastric Ulcer

In both a U.S. and an international multicenter, double-blind study in patients with endoscopically confirmed active benign gastric ulcer, orally administered PEPCID, 40 mg h.s., was compared to placebo h.s. Antacids were permitted during the studies, but consumption was not significantly different between the PEPCID and placebo groups. As shown in Table 2, the incidence of ulcer healing (dropouts counted as unhealed) with PEPCID was statistically significantly better than placebo at weeks 6 and 8 in the U.S. study, and at weeks 4, 6 and 8 in the international study, based on the number of ulcers that healed, confirmed by endoscopy.

Table 2
Patients with Endoscopically Confirmed Healed Gastric Ulcers


  U.S. Study International Study
PEPCID
40 mg h.s.
(N=74)
Placebo
h.s.
(N=75)
PEPCID
40 mg h.s.
(N=149)
Placebo
h.s.
(N=145)
Week 4 45% 39% † 47% 31%
Week 6 † 66% 44% † 65% 46%
Week 8 *** 78% 64% † 80% 54%
***,†Statistically significantly better than placebo (p ≤ 0.05, p ≤ 0.01 respectively)

Time to complete relief of daytime and nighttime pain was statistically significantly shorter for patients receiving PEPCID than for patients receiving placebo; however, in neither study was there a statistically significant difference in the proportion of patients whose pain was relieved by the end of the study (week 8).

Gastroesophageal Reflux Disease (GERD)

Orally administered PEPCID was compared to placebo in a U.S. study that enrolled patients with symptoms of GERD and without endoscopic evidence of erosion or ulceration of the esophagus. PEPCID 20 mg b.i.d. was statistically significantly superior to 40 mg h.s. and to placebo in providing a successful symptomatic outcome, defined as moderate or excellent improvement of symptoms (Table 3).

Table 3
% Successful Symptomatic Outcome


  PEPCID
20 mg b.i.d.
(N=154)
PEPCID
40 mg h.s.
(N=149)
Placebo
(N=73)
Week 6 82 †† 69 62
†† p < 0.01 vs Placebo

By two weeks of treatment, symptomatic success was observed in a greater percentage of patients taking PEPCID 20 mg b.i.d. compared to placebo (p ≤ 0.01).

Symptomatic improvement and healing of endoscopically verified erosion and ulceration were studied in two additional trials. Healing was defined as complete resolution of all erosions or ulcerations visible with endoscopy. The U.S. study comparing PEPCID 40 mg p.o. b.i.d. to placebo and PEPCID 20 mg p.o. b.i.d., showed a significantly greater percentage of healing for PEPCID 40 mg b.i.d. at weeks 6 and 12 (Table 4).

Table 4
% Endoscopic Healing - U.S. Study


  PEPCID
40 mg b.i.d.
(N=127)
PEPCID
20 mg b.i.d.
(N=125)
Placebo
(N=66)
Week 6 48 †††,‡‡ 32 18
Week 12 69 †††,‡ 54 ††† 29
††† p < 0.01 vs Placebo
‡ p < 0.05 vs PEPCID 20 mg b.i.d.
‡‡ p < 0.01 vs PEPCID 20 mg b.i.d.

As compared to placebo, patients who received PEPCID had faster relief of daytime and nighttime heartburn and a greater percentage of patients experienced complete relief of nighttime heartburn. These differences were statistically significant.

In the international study, when PEPCID 40 mg p.o. b.i.d. was compared to ranitidine 150 mg p.o. b.i.d., a statistically significantly greater percentage of healing was observed with PEPCID 40 mg b.i.d. at week 12 (Table 5). There was, however, no significant difference among treatments in symptom relief.

Table 5
% Endoscopic Healing - International Study


  PEPCID
40 mg b.i.d.
(N=175)
PEPCID
20 mg b.i.d.
(N=93)
Ranitidine
150 mg b.i.d.
(N=172)
Week 6 48 52 42
Week 12 71 ‡‡‡ 68 60
‡‡‡ p < 0.05 vs Ranitidine 150 mg b.i.d.

 

Pathological Hypersecretory Conditions (e.g., Zollinger-Ellison Syndrome, Multiple Endocrine Adenomas)

In studies of patients with pathological hypersecretory conditions such as Zollinger-Ellison Syndrome with or without multiple endocrine adenomas, PEPCID significantly inhibited gastric acid secretion and controlled associated symptoms. Orally administered doses from 20 to 160 mg q 6 h maintained basal acid secretion below 10 mEq/hr; initial doses were titrated to the individual patient need and subsequent adjustments were necessary with time in some patients. PEPCID was well tolerated at these high dose levels for prolonged periods (greater than 12 months) in eight patients, and there were no cases reported of gynecomastia, increased prolactin levels, or impotence which were considered to be due to the drug.

IN PEDIATRIC PATIENTS

Pharmacokinetics

Table 6 presents pharmacokinetic data from clinical trials and a published study in pediatric patients ( < 1 year of age; N=27) given famotidine I.V. 0.5 mg/kg and from published studies of small numbers of pediatric patients (1-15 years of age) given famotidine intravenously. Areas under the curve (AUCs) are normalized to a dose of 0.5 mg/kg I.V. for pediatric patients 1-15 years of age and compared with an extrapolated 40 mg intravenous dose in adults (extrapolation based on results obtained with a 20 mg I.V. adult dose).

Table 6
Pharmacokinetic Parametersa of Intravenous Famotidine


Age
(N = number of patients)
Area Under the Curve (AUC)
(ng-hr/mL)
Total Clearance (Cl)
(L/hr/kg)
Volume of Distribution (Vd)
(L/kg)
Elimination Half-life (T½)
(hours)
0-1 monthc (N=10) NA 0.13 ± 0.06 1.4 ± 0.4 10.5 ± 5.4
0-3 monthsd (N=6) 2688 ± 847 0.21 ± 0.06 1.8 ± 0.3 8.1 ± 3.5
> 3-12 monthsd (N=11) 1160 ± 474 0.49 ± 0.17 2.3 ± 0.7 4.5 ± 1.1
1-11 yrs (N=20) 1089 ± 834 0.54 ± 0.34 2.07 ± 1.49 3.38 ± 2.60
11-15 yrs (N=6) 1140 ± 320 0.48 ± 0.14 1.5 ± 0.4 2.3 ± 0.4
Adult (N=16) b 1726 0.39 ± 0.14 1.3 ± 0.2 2.83 ± 0.99
a Values are presented as means ± SD unless indicated otherwise.
b Mean value only.
c Single center study.
d Multicenter study.

Plasma clearance is reduced and elimination half-life is prolonged in pediatric patients 0-3 months of age compared to older pediatric patients. The pharmacokinetic parameters for pediatric patients, ages > 3 months-15 years, are comparable to those obtained for adults.

Bioavailability studies of 8 pediatric patients (11-15 years of age) showed a mean oral bioavailability of 0.5 compared to adult values of 0.42 to 0.49. Oral doses of 0.5 mg/kg achieved AUCs of 645 ± 249 ng-hr/mL and 580 ± 60 ng-hr/mL in pediatric patients < 1 year of age (N=5) and in pediatric patients 11-15 years of age, respectively, compared to 482 ± 181 ng-hr/mL in adults treated with 40 mg orally.

Pharmacodynamics

Pharmacodynamics of famotidine were evaluated in 5 pediatric patients 2-13 years of age using the sigmoid Emax model. These data suggest that the relationship between serum concentration of famotidine and gastric acid suppression is similar to that observed in one study of adults (Table 7).

Table 7
Pharmacodynamics of famotidine using the sigmoid Emax model


  EC50 (ng/mL)*
Pediatric Patients 26 ± 13
Data from one study  
a) healthy adult subjects 26.5 ± 10.3
b) adult patients with upper GI bleeding 18.7 ± 10.8
*Serum concentration of famotidine associated with 50% maximum gastric acid reduction. Values are presented as means ± SD.

Five published studies (Table 8) examined the effect of famotidine on gastric pH and duration of acid suppression in pediatric patients. While each study had a different design, acid suppression data over time are summarized as follows:

Table 8


Dosage Route Effecta Number of Patients
(age range)
0.5 mg/kg, single dose I.V. gastric pH > 4 for 19.5 hours (17.3, 21.8)c 11 (5-19 days)
0.3 mg/kg, single dose I.V. gastric pH > 3.5 for 8.7 ± 4.7 hours b 6 (2-7 years)
0.4-0.8 mg/kg I.V. gastric pH > 4 for 6-9 hours 18 (2-69 months)
0.5 mg/kg, single dose I.V. a > 2 pH unit increase above baseline in gastric pH for > 8 hours 9 (2-13 years)
0.5 mg/kg b.i.d. I.V. gastric pH > 5 for 13.5 ± 1.8 hoursb 4 (6-15 years)
0.5 mg/kg b.i.d. oral gastric pH > 5 for 5.0 ± 1.1 hoursb 4 (11-15 years)
a Values reported in published literature.
b Means ± SD.
c Mean (95% confidence interval).

The duration of effect of famotidine I.V. 0.5 mg/kg on gastric pH and acid suppression was shown in one study to be longer in pediatric patients < 1 month of age than in older pediatric patients. This longer duration of gastric acid suppression is consistent with the decreased clearance in pediatric patients < 3 months of age (see Table 6).

Clinical pharmacology in adults

GI Effects

Pepcid is a competitive inhibitor of histamine H2-receptors. The primary clinically important pharmacologic activity of Pepcid is inhibition of gastric secretion. Both the acid concentration and volume of gastric secretion are suppressed by PEPCID, while changes in pepsin secretion are proportional to volume output.

In normal volunteers and hypersecretors, Pepcid inhibited basal and nocturnal gastric secretion, as well as secretion stimulated by food and pentagastrin. After oral administration, the onset of the antisecretory effect occurred within one hour; the maximum effect was dose-dependent, occurring within one to three hours. Duration of inhibition of secretion by doses of 20 and 40 mg was 10 to 12 hours.

After intravenous administration, the maximum effect was achieved within 30 minutes. Single intravenous doses of 10 and 20 mg inhibited nocturnal secretion for a period of 10 to 12 hours. The 20 mg dose was associated with the longest duration of action in most subjects.

Single evening oral doses of 20 and 40 mg inhibited basal and nocturnal acid secretion in all subjects; mean nocturnal gastric acid secretion was inhibited by 86% and 94%, respectively, for a period of at least 10 hours. The same doses given in the morning suppressed food-stimulated acid secretion in all subjects. The mean suppression was 76% and 84%, respectively, 3 to 5 hours after administration, and 25% and 30%, respectively, 8 to 10 hours after administration. In some subjects who received the 20 mg dose, however, the antisecretory effect was dissipated within 6-8 hours. There was no cumulative effect with repeated doses. The nocturnal intragastric pH was raised by evening doses of 20 and 40 mg of Pepcid to mean values of 5.0 and 6.4, respectively. When Pepcid was given after breakfast, the basal daytime interdigestive pH at 3 and 8 hours after 20 or 40 mg of PEPCID was raised to about 5.

Pepcid had little or no effect on fasting or postprandial serum gastrin levels. Gastric emptying and exocrine pancreatic function were not affected by PEPCID.

Other Effects

Systemic effects of Pepcid in the CNS, cardiovascular, respiratory or endocrine systems were not noted in clinical pharmacology studies. Also, no antiandrogenic effects were noted. (See ADVERSE REACTIONS.) Serum hormone levels, including prolactin, cortisol, thyroxine (T4), and testosterone, were not altered after treatment with PEPCID.

Pharmacokinetics

Orally administered Pepcid is incompletely absorbed and its bioavailability is 40-45%. Pepcid undergoes minimal first-pass metabolism. After oral doses, peak plasma levels occur in 1-3 hours. Plasma levels after multiple doses are similar to those after single doses. Fifteen to 20% of Pepcid in plasma is protein bound. PEPCID has an elimination half-life of 2.5-3.5 hours. Pepcid is eliminated by renal (65-70%) and metabolic (30-35%) routes. Renal clearance is 250-450 mL/min, indicating some tubular excretion. Twenty-five to 30% of an oral dose and 65-70% of an intravenous dose are recovered in the urine as unchanged compound. The only metabolite identified in man is the S-oxide.

There is a close relationship between creatinine clearance values and the elimination half-life of PEPCID. In patients with severe renal insufficiency, i.e., creatinine clearance less than 10 mL/min, the elimination half-life of PEPCID may exceed 20 hours and adjustment of dose or dosing intervals in moderate and severe renal insufficiency may be necessary (see PRECAUTIONS, DOSAGE AND ADMINISTRATION).

In elderly patients, there are no clinically significant age-related changes in the pharmacokinetics of PEPCID. However, in elderly patients with decreased renal function, the clearance of the drug may be decreased (see PRECAUTIONS, Geriatric Use).

Clinical Studies

The majority of clinical study experience involved oral administration of Pepcid Tablets, and is provided herein for reference.

Duodenal Ulcer

In a U.S. multicenter, double-blind study in outpatients with endoscopically confirmed duodenal ulcer, orally administered Pepcid was compared to placebo. As shown in Table 1, 70% of patients treated with Pepcid 40 mg h.s. were healed by week 4.


Table 1: Outpatients with Endoscopically Confirmed Healed Duodenal Ulcers
  PEPCID
40 mg h.s.
(N=89)
PEPCID
20 mg b.i.d.
(N=84)
Placebo
h.s.
(N=97)
Week 2 *32% *38% 17%
* Statistically significantly different than placebo (p<0.001)
Week 4 *70% *67% 31%


Patients not healed by week 4 were continued in the study. By week 8, 83% of patients treated with Pepcid had healed versus 45% of patients treated with placebo. The incidence of ulcer healing with Pepcid was significantly higher than with placebo at each time point based on proportion of endoscopically confirmed healed ulcers.

In this study, time to relief of daytime and nocturnal pain was significantly shorter for patients receiving Pepcid than for patients receiving placebo; patients receiving Pepcid also took less antacid than the patients receiving placebo.

Long-Term Maintenance

Treatment of Duodenal Ulcers

PEPCID, 20 mg p.o. h.s. was compared to placebo h.s. as maintenance therapy in two double-blind, multicenter studies of patients with endoscopically confirmed healed duodenal ulcers. In the U.S. study the observed ulcer incidence within 12 months in patients treated with placebo was 2.4 times greater than in the patients treated with PEPCID. The 89 patients treated with Pepcid had a cumulative observed ulcer incidence of 23.4% compared to an observed ulcer incidence of 56.6% in the 89 patients receiving placebo (p<0.01). These results were confirmed in an international study where the cumulative observed ulcer incidence within 12 months in the 307 patients treated with Pepcid was 35.7%, compared to an incidence of 75.5% in the 325 patients treated with placebo (p<0.01).

Gastric Ulcer

In both a U.S. and an international multicenter, double-blind study in patients with endoscopically confirmed active benign gastric ulcer, orally administered PEPCID, 40 mg h.s., was compared to placebo h.s. Antacids were permitted during the studies, but consumption was not significantly different between the PEPCID and placebo groups. As shown in Table 2, the incidence of ulcer healing (dropouts counted as unhealed) with Pepcid was statistically significantly better than placebo at weeks 6 and 8 in the U.S. study, and at weeks 4, 6 and 8 in the international study, based on the number of ulcers that healed, confirmed by endoscopy.


Table 2: Patients with Endoscopically Confirmed Healed Gastric Ulcers
 
U.S. Study
International Study
  PEPCID
40 mg h.s.
(N=74)
Placebo
h.s.
(N=75)
PEPCID
40 mg h.s.
(N=149)
Placebo
h.s.
(N=145)
* Statistically significantly better than placebo p≤0.01 † Statistically significantly better than placebo p≤0.05
Week 4 45% 39% *47% 31%
Week 6 *66% 44% *65% 46%
Week 8 †78% 64% *80% 54%

Time to complete relief of daytime and nighttime pain was statistically significantly shorter for patients receiving Pepcid than for patients receiving placebo; however, in neither study was there a statistically significant difference in the proportion of patients whose pain was relieved by the end of the study (week 8).

Gastroesophageal Reflux Disease (GERD)

Orally administered Pepcid was compared to placebo in a U.S. study that enrolled patients with symptoms of GERD and without endoscopic evidence of erosion or ulceration of the esophagus. PEPCID 20 mg b.i.d. was statistically significantly superior to 40 mg h.s. and to placebo in providing a successful symptomatic outcome, defined as moderate or excellent improvement of symptoms (Table 3).


Table 3: % Successful Symptomatic Outcome
  PEPCID
20 mg b.i.d.
(N=154)
PEPCID
40 mg h.s.
(N=149)

Placebo
(N=73)
* p≤0.01 vs Placebo
Week 6 82* 69 62

By two weeks of treatment, symptomatic success was observed in a greater percentage of patients taking Pepcid 20 mg b.i.d. compared to placebo (p≤0.01).

Symptomatic improvement and healing of endoscopically verified erosion and ulceration were studied in two additional trials. Healing was defined as complete resolution of all erosions or ulcerations visible with endoscopy. The U.S. study comparing Pepcid 40 mg p.o. b.i.d. to placebo and Pepcid 20 mg p.o. b.i.d., showed a significantly greater percentage of healing for Pepcid 40 mg b.i.d. at weeks 6 and 12 (Table 4).

Table 4: % Endoscopic Healing - U.S. Study
  PEPCID
40 mg b.i.d.
(N=127)
PEPCID
20 mg b.i.d.
(N=125)

Placebo
(N=66)
* p≤0.01 vs Placebo † p≤0.01 vs Pepcid 20 mg b.i.d. ‡ p≤0.05 vs Pepcid 20 mg b.i.d.
Week 6 48*,† 32 18
Week 12 69*,‡ 54* 29

As compared to placebo, patients who received PEPCID had faster relief of daytime and nighttime heartburn and a greater percentage of patients experienced complete relief of nighttime heartburn. These differences were statistically significant.

In the international study, when Pepcid 40 mg p.o. b.i.d. was compared to ranitidine 150 mg p.o. b.i.d., a statistically significantly greater percentage of healing was observed with Pepcid 40 mg b.i.d. at week 12 (Table 5). There was, however, no significant difference among treatments in symptom relief.


Table 5: % Endoscopic Healing - International Study
  PEPCID
40 mg b.i.d.
(N=175)
PEPCID
20 mg b.i.d.
(N=93)
Ranitidine
150 mg b.i.d.
(N=172)
* p≤0.05 vs Ranitidine 150 mg b.i.d.
Week 6 48 52 42
Week 12 71* 68 60

Pathological Hypersecretory Conditions (e.g., Zollinger-Ellison Syndrome, Multiple Endocrine Adenomas)

In studies of patients with pathological hypersecretory conditions such as Zollinger-Ellison Syndrome with or without multiple endocrine adenomas, Pepcid significantly inhibited gastric acid secretion and controlled associated symptoms. Orally administered doses from 20 to 160 mg q 6 h maintained basal acid secretion below 10 mEq/hr; initial doses were titrated to the individual patient need and subsequent adjustments were necessary with time in some patients. Pepcid was well tolerated at these high dose levels for prolonged periods (greater than 12 months) in eight patients, and there were no cases reported of gynecomastia, increased prolactin levels, or impotence which were considered to be due to the drug.

Clinical pharmacology in pediatric patients

Pharmacokinetics

Table 6 presents pharmacokinetic data from clinical trials and a published study in pediatric patients (<1 year of age; N=27) given famotidine I.V. 0.5 mg/kg and from published studies of small numbers of pediatric patients (1-15 years of age) given famotidine intravenously. Areas under the curve (AUCs) are normalized to a dose of 0.5 mg/kg I.V. for pediatric patients 1-15 years of age and compared with an extrapolated 40 mg intravenous dose in adults (extrapolation based on results obtained with a 20 mg I.V. adult dose).


Table 6: Pharmacokinetic Parameters* of Intravenous Famotidine
Age
(N=number of
patients)
Area Under
the Curve (AUC)
(ng-hr/mL)
Total
Clearance (Cl)
(L/hr/kg)
Volume of
Distribution (Vd)
(L/kg)
Elimination
Half-life (T½)
(hours)
* Values are presented as means ± SD unless indicated otherwise. † Single center study. ‡ Multicenter study. § Mean value only.
0-1 month† (N=10) NA 0.13 ± 0.06 1.4 ± 0.4 10.5 ± 5.4
0-3 months‡ (N=6) 2688 ± 847 0.21 ± 0.06 1.8 ± 0.3 8.1 ± 3.5
>3-12 months‡ (N=11) 1160 ± 474 0.49 ± 0.17 2.3 ± 0.7 4.5 ± 1.1
1-11 yrs (N=20) 1089 ± 834 0.54 ± 0.34 2.07 ± 1.49 3.38 ± 2.60
11-15 yrs (N=6) 1140 ± 320 0.48 ± 0.14 1.5 ± 0.4 2.3 ± 0.4
Adult (N=16) 1726§ 0.39 ± 0.14 1.3 ± 0.2 2.83 ± 0.99


Plasma clearance is reduced and elimination half-life is prolonged in pediatric patients 0-3 months of age compared to older pediatric patients. The pharmacokinetic parameters for pediatric patients, ages >3 months-15 years, are comparable to those obtained for adults.

Bioavailability studies of 8 pediatric patients (11-15 years of age) showed a mean oral bioavailability of 0.5 compared to adult values of 0.42 to 0.49. Oral doses of 0.5 mg/kg achieved AUCs of 645 ± 249 ng-hr/mL and 580 ± 60 ng-hr/mL in pediatric patients <1 year of age (N=5) and in pediatric patients 11-15 years of age, respectively, compared to 482 ± 181 ng-hr/mL in adults treated with 40 mg orally.

Pharmacodynamics

Pharmacodynamics of famotidine were evaluated in 5 pediatric patients 2-13 years of age using the sigmoid Emax model. These data suggest that the relationship between serum concentration of famotidine and gastric acid suppression is similar to that observed in one study of adults (Table 7).


Table 7: Pharmacodynamics of famotidine using the sigmoid Emax model
EC50 (ng/mL)*
* Serum concentration of famotidine associated with 50% maximum gastric acid reduction. Values are presented as means ± SD.
Pediatric Patients 26 ± 13


Data from one study
a) healthy adult subjects 26.5 ± 10.3
b) adult patients with upper GI bleeding 18.7 ± 10.8


Five published studies (Table 8) examined the effect of famotidine on gastric pH and duration of acid suppression in pediatric patients. While each study had a different design, acid suppression data over time are summarized as follows:


Table 8
Dosage
Route
Effect*
Number of Patients
(age range)
* Values reported in published literature. † Mean (95% confidence interval). ‡ Means ± SD.
0.5 mg/kg, single dose I.V. gastric pH >4 for 19.5 hours (17.3, 21.8)† 11 (5-19 days)
0.3 mg/kg, single dose I.V. gastric pH >3.5 for 8.7 ± 4.7‡ hours 6 (2-7 years)
0.4-0.8 mg/kg I.V. gastric pH >4 for 6-9 hours 18 (2-69 months)
0.5 mg/kg, single dose I.V. a >2 pH unit increase above baseline in gastric pH for >8 hours 9 (2-13 years)
0.5 mg/kg b.i.d. I.V. gastric pH >5 for 13.5 ± 1.8‡ hours 4 (6-15 years)
0.5 mg/kg b.i.d. oral gastric pH >5 for 5.0 ± 1.1‡ hours 4 (11-15 years)


The duration of effect of famotidine I.V. 0.5 mg/kg on gastric pH and acid suppression was shown in one study to be longer in pediatric patients <1 month of age than in older pediatric patients. This longer duration of gastric acid suppression is consistent with the decreased clearance in pediatric patients <3 months of age (see Table 6).

Dosage and administration

In some hospitalized patients with pathological hypersecretory conditions or intractable ulcers, or in patients who are unable to take oral medication, Pepcid Injection Premixed or Pepcid Injection may be administered until oral therapy can be instituted.

The recommended dosage for Pepcid Injection Premixed and Pepcid Injection in adult patients is 20 mg intravenously q 12 h.

The doses and regimen for parenteral administration in patients with GERD have not been established.

Dosage for Pediatric Patients<1 year of age Gastroesophageal Reflux Disease (GERD)

See PRECAUTIONS, Pediatric Patients <1 year of age.

The studies described in PRECAUTIONS, Pediatric Patients <1 year of age suggest the following starting doses in pediatric patients<1 year of age: Gastroesophageal Reflux Disease (GERD) - 0.5 mg/kg/dose of famotidine oral suspension for the treatment of GERD for up to 8 weeks once daily in patients <3 months of age and 0.5 mg/kg/dose twice daily in patients 3 months to <1 year of age. Patients should also be receiving conservative measures (e.g., thickened feedings). The use of intravenous famotidine in pediatric patients <1 year of age with GERD has not been adequately studied.

Dosage for Pediatric Patients 1-16 years of age

See PRECAUTIONS, Pediatric Patients 1-16 years of age.

The studies described in PRECAUTIONS, Pediatric Patients 1-16 years of age suggest that the starting dose in pediatric patients 1-16 years of age is 0.25 mg/kg intravenously (injected over a period of not less than two minutes or as a 15-minute infusion) q 12 h up to 40 mg/day.

While published uncontrolled clinical studies suggest effectiveness of famotidine in the treatment of peptic ulcer, data in pediatric patients are insufficient to establish percent response with dose and duration of therapy. Therefore, treatment duration (initially based on adult duration recommendations) and dose should be individualized based on clinical response and/or gastric pH determination and endoscopy. Published uncontrolled studies in pediatric patients 1-16 years of age have demonstrated gastric acid suppression with doses up to 0.5 mg/kg intravenously q 12 h.

Dosage Adjustments for Patients with Moderate or Severe Renal Insufficiency

In adult patients with moderate (creatinine clearance<50 mL/min) or severe (creatinine clearance <10 mL/min) renal insufficiency, the elimination half-life of Pepcid is increased. For patients with severe renal insufficiency, it may exceed 20 hours, reaching approximately 24 hours in anuric patients. Since CNS adverse effects have been reported in patients with moderate and severe renal insufficiency, to avoid excess accumulation of the drug in patients with moderate or severe renal insufficiency, the dose of Pepcid Injection Premixed or Pepcid Injection may be reduced to half the dose, or the dosing interval may be prolonged to 36-48 hours as indicated by the patient's clinical response.

Based on the comparison of pharmacokinetic parameters for Pepcid in adults and pediatric patients, dosage adjustment in pediatric patients with moderate or severe renal insufficiency should be considered.

Pathological Hypersecretory Conditions (e.g., Zollinger-Ellison Syndrome, Multiple Endocrine Adenomas)

The dosage of Pepcid in patients with pathological hypersecretory conditions varies with the individual patient. The recommended adult intravenous dose is 20 mg q 12 h. Doses should be adjusted to individual patient needs and should continue as long as clinically indicated. In some patients, a higher starting dose may be required. Oral doses up to 160 mg q 6 h have been administered to some adult patients with severe Zollinger-Ellison Syndrome.

Pepcid Injection Premixed

Pepcid Injection Premixed, supplied in Galaxy2 containers (PL 2501 Plastic), is a 50 mL iso-osmotic solution premixed with 0.9% sodium chloride for administration as an infusion over a 15-30 minute period. This premixed solution is for intravenous use only using sterile equipment.

2  Galaxy® is a registered trademark of Baxter International Inc.

Directions for Use of Galaxy® Containers

Check the container for minute leaks prior to use by squeezing the bag firmly. If leaks are found, discard solution as sterility may be impaired. Do not add supplementary medication. Do not use unless solution is clear and seal is intact.

CAUTION: Do not use plastic containers in series connections. Such use could result in air embolism due to residual air being drawn from the primary container before administration of the fluid from the secondary container is complete.

Preparation for administration: 

  1. Suspend container from eyelet support.
  2. Remove plastic protector from outlet port at bottom of container.
  3. Attach administration set. Refer to complete directions accompanying set.

To prepare Pepcid intravenous solutions, aseptically dilute 2 mL of Pepcid Injection (solution containing 10 mg/mL) with 0.9% Sodium Chloride Injection or other compatible intravenous solution (see Stability, Pepcid Injection) to a total volume of either 5 mL or 10 mL and inject over a period of not less than 2 minutes.

To prepare Pepcid intravenous infusion solutions, aseptically dilute 2 mL of Pepcid Injection with 100 mL of 5% dextrose or other compatible solution (see Stability, Pepcid Injection), and infuse over a 15-30 minute period.

Concomitant Use of Antacids

Antacids may be given concomitantly if needed.

Stability

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit.

Pepcid Injection Premixed

Pepcid Injection Premixed, as supplied premixed in 0.9% sodium chloride in Galaxy® containers (PL 2501 Plastic), is stable through the labeled expiration date when stored under the recommended conditions. (See HOW SUPPLIED, Storage.)

Pepcid Injection

When added to or diluted with most commonly used intravenous solutions, e.g., Water for Injection, 0.9% Sodium Chloride Injection, 5% and 10% Dextrose Injection, or Lactated Ringer's Injection, diluted Pepcid Injection is physically and chemically stable (i.e., maintains at least 90% of initial potency) for 7 days at room temperature  see HOW SUPPLIED, Storage.

When added to or diluted with Sodium Bicarbonate Injection, 5%, Pepcid Injection at a concentration of 0.2 mg/mL (the recommended concentration of Pepcid intravenous infusion solutions) is physically and chemically stable (i.e., maintains at least 90% of initial potency) for 7 days at room temperature  see HOW SUPPLIED, Storage. However, a precipitate may form at higher concentrations of Pepcid Injection (>0.2 mg/mL) in Sodium Bicarbonate Injection, 5%.

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