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HIGHLIGHTS OF PRESCRIBING INFORMATION These highlights do not include all the information needed to use PROTONIX safely and effectively. See full prescribing information for PROTONIX.
PROTONIX (pantoprazole sodium) delayed-release tablets PROTONIX (pantoprazole sodium) for delayed-release oral suspension Initial U.S. approval: 2000
———————— RECENT MAJOR CHANGES ———————— Warnings and Precautions, Concomitant use of Protonix with Methotrexate (5.8) 5/
———————— INDICATIONS AND USAGE ———————— PROTONIX is a proton pump inhibitor indicated for the following: Short-Term Treatment of Erosive Esophagitis Associated with Gastroesophageal Reflux Disease (GERD) (1.1) Maintenance of Healing of Erosive Esophagitis (1.2) Pathological Hypersecretory Conditions Including Zollinger- Ellison Syndrome (1.3) ——————— DOSAGE AND ADMINISTRATION —————— Indication Dose Frequency Short-Term Treatment of Erosive Esophagitis Associated With GERD (2.1) Adults 40 mg Once Daily for up to 8 wks Children (5 years and older) ≥ 15 kg to < 40 kg 20 mg Once Daily for up to 8 wks ≥ 40 kg 40 mg Maintenance of Healing of Erosive Esophagitis (2.1) Adults 40 mg Once Daily Pathological Hypersecretory Conditions Including Zollinger-Ellison Syndrome (2.1) Adults 40 mg Twice Daily See full prescribing information for administration instructions
—————— DOSAGE FORMS AND STRENGTHS —————— Delayed-Release Tablets, 20 mg and 40 mg (3) For Delayed-Release Oral Suspension, 40 mg (3) ————————— CONTRAINDICATIONS ———————— Known hypersensitivity to any component of the formulation or to substituted benzimidazoles (4) ——————— WARNINGS AND PRECAUTIONS —————— Symptomatic response does not preclude presence of gastric malignancy (5.1) Atrophic gastritis has been noted with long-term therapy (5.2) Bone Fracture: Long-term and multiple daily dose PPI therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist or spine. (5.4) Hypomagnesemia has been reported rarely with prolonged treatment with PPIs (5.5)
————————— ADVERSE REACTIONS ————————— The most frequently occurring adverse reactions are as follows: For adult use (>2%) are headache, diarrhea, nausea, abdominal pain, vomiting, flatulence, dizziness, and arthralgia. (6) For pediatric use (>4%) are URI, headache, fever, diarrhea, vomiting, rash, and abdominal pain. (6) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Incat 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch ————————— DRUG INTERACTIONS ————————— Do not co-administer with atazanavir or nelfinavir (7.1) Concomitant warfarin use may require monitoring (7.2) May interfere with the absorption of drugs where gastric pH is important for bioavailability (7.4) May produce false-positive urine screen for THC (7.5) Methotrexate: Protonix may increase serum level of methotrexate (7.6) See 17 for PATIENT COUNSELING INFORMATION and FDA-approved patient labeling. Revised: 05/
FULL PRESCRIBING INFORMATION: CONTENTS * 1 INDICATIONS AND USAGE 1.1 Short-Term Treatment of Erosive Esophagitis Associated With Gastroesophageal Reflux Disease (GERD) 1.2 Maintenance of Healing of Erosive Esophagitis 1.3 Pathological Hypersecretory Conditions Including Zollinger-Ellison Syndrome 2 DOSAGE AND ADMINISTRATION 2.1 Recommended Dosing Schedule 2.2 Administration Instructions 3 DOSAGE FORMS AND STRENGTHS 4 CONTRAINDICATIONS 5 WARNINGS AND PRECAUTIONS 5.1 Concurrent Gastric Malignancy 5.2 Atrophic Gastritis 5.3 Cyanocobalamin (Vitamin B-12) Deficiency 5.4 Bone Fracture 5.5 Hypomagnesemia 5.6 Tumorigenicity 5.7 Interference with Urine Screen for THC 5.8 Concomitant use PROTONIX with Methotrexate 6 ADVERSE REACTIONS 6.1 Clinical Trial Experience 6.2 Postmarketing Experience 7 DRUG INTERACTIONS 7.1 Interference with Antiretroviral Therapy 7.2 Coumarin Anticoagulants 7.3 Clopidogrel 7.4 Drugs for Which Gastric pH Can Affect Bioavailability 7.5 False Positive Urine Tests for THC
8 USE IN SPEC FIC POPULATIONSI 8.1 Pregnancy 8.3 Nursing Mothers 8.4 Pediatric Use 8.5 Geriatric Use 8.6 Gender 8.7 Patients with He atic Impairmentp 10 OVERDOSAGE 11 DESCRIPTION 12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action 12.2 Pharmacodynamics 12.3 Pharmacokinetics 12.4 Pharmacogenomics 13 NONCLINICAL TOXICOLOGY 13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility 13.2 Animal Toxicology and/or Pharmacology 14 CLINICAL STUDIES 14.1 Erosive Esophagitis (EE) Associated with Gastroesophageal Reflux Disease (GERD) 14.2 Long-Term Maintenance of Healing of Erosive Esophagitis 14.3 Pathological Hypersecretory Conditions Including Zollinger-Ellison Syndrome 16 HOW SUPPLIED/STORAGE AND HANDLING 17 PATIENT COUNSELING INFORMATION
- Sections or subsections omitted from the full prescribing information are not listed 7.6 Methotrexate (^1)
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FULL PRESCRIBING INFORMATION
1 INDICATIONS AND USAGE
PROTONIX For Delayed-Release Oral Suspension and PROTONIX Delayed-Release Tablets are indicated for:
1.1 Short-Term Treatment of Erosive Esophagitis Associated With Gastroesophageal Reflux Disease (GERD)
PROTONIX is indicated in adults and pediatric patients five years of age and older for the short-term treatment (up to 8 weeks) in the healing and symptomatic relief of erosive esophagitis. For those adult patients who have not healed after 8 weeks of treatment, an additional 8-week course of PROTONIX may be considered. Safety of treatment beyond 8 weeks in pediatric patients has not been established.
1.2 Maintenance of Healing of Erosive Esophagitis
PROTONIX is indicated for maintenance of healing of erosive esophagitis and reduction in relapse rates of daytime and nighttime heartburn symptoms in adult patients with GERD. Controlled studies did not extend beyond 12 months.
1.3 Pathological Hypersecretory Conditions Including Zollinger-Ellison Syndrome
PROTONIX is indicated for the long-term treatment of pathological hypersecretory conditions, including Zollinger-Ellison syndrome.
2 DOSAGE AND ADMINISTRATION
2.1 Recommended Dosing Schedule
PROTONIX is supplied as delayed-release granules in packets for preparation of oral suspensions or as delayed-release tablets. The recommended dosages are outlined in Table 1.
Do not divide the 40 mg PROTONIX For Delayed-Release Oral Suspension packet to create a 20 mg dosage for pediatric patients who are unable to take the tablet formulation.
PROTONIX For Delayed-Release Oral Suspension - Oral Administration in Applesauce
Open packet. Sprinkle granules on one teaspoonful of applesauce. DO NOT USE OTHER FOODS OR CRUSH OR CHEW THE GRANULES. Take within 10 minutes of preparation. Take sips of water to make sure granules are washed down into the stomach. Repeat water sips as necessary.
PROTONIX For Delayed-Release Oral Suspension - Oral Administration in Apple Juice
Open packet. Empty granules into a small cup or teaspoon containing one teaspoon of apple juice. Stir for 5 seconds (granules will not dissolve) and swallow immediately. To make sure that the entire dose is taken, rinse the container once or twice with apple juice to remove any remaining granules. Swallow immediately.
PROTONIX For Delayed-Release Oral Suspension - Nasogastric (NG) Tube or Gastrostomy Tube Administration
For patients who have a nasogastric tube or gastrostomy tube in place, PROTONIX For Delayed-Release Oral Suspension can be given as follows:
Remove the plunger from the barrel of a 2 ounce (60 mL) catheter-tip syringe. Discard the plunger. Connect the catheter tip of the syringe to a 16 French (or larger) tube. Hold the syringe attached to the tubing as high as possible while giving PROTONIX For Delayed-Release Oral Suspension to prevent any bending of the tubing. Empty the contents of the packet into the barrel of the syringe. Add 10 mL (2 teaspoonfuls) of apple juice and gently tap and/or shake the barrel of the syringe to help rinse the syringe and tube. Repeat at least twice more using the same amount of apple juice (10 mL or 2 teaspoonfuls) each time. No granules should remain in the syringe.
3 DOSAGE FORMS AND STRENGTHS
Delayed-Release Tablets:
40 mg, yellow oval biconvex tablets imprinted with PROTONIX (brown ink) on one side 20 mg, yellow oval biconvex tablets imprinted with P20 (brown ink) on one side
For Delayed-Release Oral Suspension:
40 mg, pale yellowish to dark brownish, enteric-coated granules in a unit dose packet
4 CONTRAINDICATIONS
PROTONIX is contraindicated in patients with known hypersensitivity to any component of the formulation [ see Description (11) ] or any substituted benzimidazole.
5 WARNINGS AND PRECAUTIONS
5.1 Concurrent Gastric Malignancy
Symptomatic response to therapy with PROTONIX does not preclude the presence of gastric malignancy.
5.2 Atrophic Gastritis
Atrophic gastritis has been noted occasionally in gastric corpus biopsies from patients treated long-term with PROTONIX, particularly in patients who were H. pylori positive.
5.3 Cyanocobalamin (Vitamin B-12) Deficiency
Generally, daily treatment with any acid-suppressing medications over a long period of time (e.g., longer than 3 years) may lead to malabsorption of cyanocobalamin (Vitamin B-12) caused by hypo- or achlorhydria. Rare reports of cyanocobalamin deficiency occurring with acid-suppressing therapy have been reported in the literature. This diagnosis should be considered if clinical symptoms consistent with cyanocobalamin deficiency are observed.
5.4 Bone Fracture
Several published observational studies suggest that proton pump inhibitor (PPI) therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist, or spine. The risk of fracture was increased in patients who received high-dose, defined as multiple daily doses, and long-term PPI therapy (a year or longer). Patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated. Patients at risk for osteoporosis-related fractures should be managed according to established treatment guidelines [see Dosage and Administration (2) and Adverse Reactions (6.2)].
5.5 Hypomagnesemia
Hypomagnesemia, symptomatic and asymptomatic, has been reported rarely in patients treated with PPIs for at least three months, in most cases after a year of therapy. Serious adverse events include tetany, arrhythmias, and seizures. In most patients, treatment of hypomagnesemia required magnesium replacement and discontinuation of the PPI.
For patients expected to be on prolonged treatment or who take PPIs with medications such as digoxin or drugs that may cause hypomagnesemia (e.g., diuretics), health care professionals
Table 3: Adverse Reactions Reported in Clinical Trials of Adult Patients with GERD at a Frequency of > 2% PROTONIX Comparators Placebo (n=1473) (n=345) (n=82) % % % Nausea 7.0 5.2 9.
Abdominal pain 6.2 4.1 6. Vomiting 4.3 3.5 2. Flatulence 3.9 2.9 3. Dizziness 3.0 2.9 1.
Arthralgia 2.8 1.4 1.
Additional adverse reactions that were reported for PROTONIX in clinical trials with a frequency of ≤ 2% are listed below by body system:
Body as a Whole: allergic reaction, pyrexia, photosensitivity reaction, facial edema
Gastrointestinal: constipation, dry mouth, hepatitis
Hematologic: leukopenia, thrombocytopenia
Metabolic/Nutritional: elevated CK (creatine kinase), generalized edema, elevated triglycerides, liver enzymes elevated
Musculoskeletal: myalgia
Nervous: depression, vertigo
Skin and Appendages: urticaria, rash, pruritus
Special Senses: blurred vision
Pediatric Patients
Safety of PROTONIX in the treatment of Erosive Esophagitis (EE) associated with GERD was evaluated in pediatric patients ages 1 year through 16 years in three clinical trials. Safety trials involved pediatric patients with EE; however, as EE is uncommon in the pediatric population, 249 pediatric patients with endoscopically-proven or symptomatic GERD were also evaluated. All adult adverse reactions to PROTONIX are considered relevant to pediatric patients. In patients ages 1 year through 16 years, the most commonly reported (> 4%) adverse reactions include: URI, headache, fever, diarrhea, vomiting, rash, and abdominal pain.
For safety information in patients less than 1 year of age see Use in Specific Populations (8.4).
Additional adverse reactions that were reported for PROTONIX in pediatric patients in clinical trials with a frequency of ≤ 4% are listed below by body system:
Body as a Whole: allergic reaction, facial edema
Gastrointestinal: constipation, flatulence, nausea
Metabolic/Nutritional: elevated triglycerides, elevated liver enzymes, elevated CK (creatine kinase)
Musculoskeletal: arthralgia, myalgia
Nervous: dizziness, vertigo
Skin and Appendages: urticaria
The following adverse reactions seen in adults in clinical trials were not reported in pediatric patients in clinical trials, but are considered relevant to pediatric patients: photosensitivity reaction, dry mouth, hepatitis, thrombocytopenia, generalized edema, depression, pruritus, leukopenia, and blurred vision.
Zollinger-Ellison Syndrome
In clinical studies of Zollinger-Ellison Syndrome, adverse reactions reported in 35 patients taking PROTONIX 80 mg/day to 240 mg/day for up to 2 years were similar to those reported in adult patients with GERD.
6.2 Postmarketing Experience
The following adverse reactions have been identified during postapproval use of PROTONIX. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
These adverse reactions are listed below by body system:
General Disorders and Administration Conditions: asthenia, fatigue, malaise
Hepatobiliary Disorders: hepatocellular damage leading to jaundice and hepatic failure
Immune System Disorders: anaphylaxis (including anaphylactic shock)
Investigations: weight changes
Metabolism and Nutritional Disorders: hyponatremia, hypomagnesemia
Musculoskeletal Disorders: rhabdomyolysis, bone fracture
Psychiatric Disorders: hallucination, confusion, insomnia, somnolence
Renal and Urinary Disorders: interstitial nephritis
methotrexate with PPIs have been conducted [ see Warnings and Precautions (5.8) ].
8 USE IN SPECIFIC POPULATIONS
8.1 Pregnancy
Teratogenic Effects
Pregnancy Category B
Reproduction studies have been performed in rats at oral doses up to 88 times the recommended human dose and in rabbits at oral doses up to 16 times the recommended human dose and have revealed no evidence of impaired fertility or harm to the fetus due to pantoprazole. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed [ see Nonclinical Toxicology (13.2) ].
8.3 Nursing Mothers
Pantoprazole and its metabolites are excreted in the milk of rats. Pantoprazole excretion in human milk has been detected in a study of a single nursing mother after a single 40 mg oral dose. The clinical relevance of this finding is not known. Many drugs which are excreted in human milk have a potential for serious adverse reactions in nursing infants. Based on the potential for tumorigenicity shown for pantoprazole in rodent carcinogenicity studies, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the benefit of the drug to the mother.
8.4 Pediatric Use
The safety and effectiveness of PROTONIX for short-term treatment (up to eight weeks) of erosive esophagitis (EE) associated with GERD have been established in pediatric patients 1 year through 16 years of age. Effectiveness for EE has not been demonstrated in patients less than 1 year of age. In addition, for patients less than 5 years of age, there is no appropriate dosage strength in an age-appropriate formulation available. Therefore, PROTONIX is indicated for the short-term treatment of EE associated with GERD for patients 5 years and older. The safety and effectiveness of PROTONIX for pediatric uses other than EE have not been established.
1 year through 16 years of age
Use of PROTONIX in pediatric patients 1 year through 16 years of age for short-term treatment (up to eight weeks) of EE associated with GERD is supported by: a) extrapolation of results from adequate and well-controlled studies that supported the approval of PROTONIX for treatment of EE associated with GERD in adults, and b) safety, effectiveness, and pharmacokinetic studies performed in pediatric patients [ see Clinical Studies (14.1), and Clinical Pharmacology (12.3) ].
Safety of PROTONIX in the treatment of EE associated with GERD in pediatric patients 1 through 16 years of age was evaluated in three multicenter, randomized, double-blind, parallel- treatment studies, involving 249 pediatric patients, including 8 with EE (4 patients ages 1 year to 5 years and 4 patients 5 years to 11 years). The children ages 1 year to 5 years with endoscopically diagnosed EE (defined as an endoscopic Hetzel-Dent score ≥ 2) were treated once daily for 8 weeks with one of two dose levels of PROTONIX (approximating 0.6 mg/kg or 1.2 mg/kg). All 4 of these patients with EE were healed (Hetzel-Dent score of 0 or 1) at 8 weeks. Because EE is uncommon in the pediatric population, predominantly pediatric patients with endoscopically-proven or symptomatic GERD were also included in these studies. Patients were treated with a range of doses of PROTONIX once daily for 8 weeks. For safety findings see Adverse Reactions (6.1). Because these pediatric trials had no placebo, active comparator, or evidence of a dose response, the trials were inconclusive regarding the clinical benefit of PROTONIX for symptomatic GERD in the pediatric population. The effectiveness of PROTONIX for treating symptomatic GERD in pediatric patients has not been established.
Although the data from the clinical trials support use of PROTONIX for the short-term treatment of EE associated with GERD in pediatric patients 1 year through 5 years, there is no commercially available dosage formulation appropriate for patients less than 5 years of age [ see Dosage and Administration ( 2 ) ].
In a population pharmacokinetic analysis, clearance values in the children 1 to 5 years old with endoscopically proven GERD had a median value of 2.4 L/h. Following a 1.2 mg/kg equivalent dose (15 mg for ≤ 12.5 kg and 20 mg for > 12.5 to < 25 kg), the plasma concentrations of pantoprazole were highly variable and the median time to peak plasma concentration was 3 to 6 hours. The estimated AUC for patients 1 to 5 years old was 37% higher than for adults receiving a single 40 mg tablet, with a geometric mean AUC value of 6.8 μg•hr/mL.
Neonates to less than one year of age
PROTONIX was not found to be effective in a multicenter, randomized, double-blind, placebo-controlled, treatment-withdrawal study of 129 pediatric patients 1 through 11 months of age. Patients were enrolled if they had symptomatic GERD based on medical history and had not responded to non-pharmacologic interventions for GERD for two weeks. Patients received PROTONIX daily for four weeks in an open-label phase, then patients were randomized in equal proportion to receive PROTONIX treatment or placebo for the subsequent four weeks in a double-blind manner. Efficacy was assessed by observing the time from randomization to study discontinuation due to symptom worsening during the four-week treatment-withdrawal phase. There was no statistically significant difference between PROTONIX and placebo in the rate of discontinuation.
In this trial, the adverse reactions that were reported more commonly (difference of ≥ 4%) in the treated population compared to the placebo population were elevated CK, otitis media, rhinitis, and laryngitis.
In a population pharmacokinetic analysis, the systemic exposure was higher in patients less than 1 year of age with GERD compared to adults who received a single 40 mg dose (geometric mean AUC was 103% higher in preterm infants and neonates receiving single dose
Single oral doses of pantoprazole at 709 mg/kg, 798 mg/kg, and 887 mg/kg were lethal to mice, rats, and dogs, respectively. The symptoms of acute toxicity were hypoactivity, ataxia, hunched sitting, limb-splay, lateral position, segregation, absence of ear reflex, and tremor.
11 DESCRIPTION
The active ingredient in PROTONIX (pantoprazole sodium) For Delayed-Release Oral Suspension and PROTONIX (pantoprazole sodium) Delayed-Release Tablets is a substituted benzimidazole, sodium 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridinyl)methyl] sulfinyl] 1 H -benzimidazole sesquihydrate, a compound that inhibits gastric acid secretion. Its empirical formula is C 16 H 14 F 2 N 3 NaO 4 S x 1.5 H 2 O, with a molecular weight of 432.4. The structural formula is:
Pantoprazole sodium sesquihydrate is a white to off-white crystalline powder and is racemic. Pantoprazole has weakly basic and acidic properties. Pantoprazole sodium sesquihydrate is freely soluble in water, very slightly soluble in phosphate buffer at pH 7.4, and practically insoluble in n-hexane.
The stability of the compound in aqueous solution is pH-dependent. The rate of degradation increases with decreasing pH. At ambient temperature, the degradation half-life is approximately 2.8 hours at pH 5 and approximately 220 hours at pH 7.8.
PROTONIX (pantoprazole sodium) is supplied as a for delayed-release oral suspension, available in one strength (40 mg), and as a delayed-release tablet, available in two strengths (20 mg and 40 mg).
Each PROTONIX (pantoprazole sodium) Delayed-Release Tablet contains 45.1 mg or 22.56 mg of pantoprazole sodium sesquihydrate (equivalent to 40 mg or 20 mg pantoprazole, respectively) with the following inactive ingredients: calcium stearate, crospovidone, hypromellose, iron oxide, mannitol, methacrylic acid copolymer, polysorbate 80, povidone, propylene glycol, sodium carbonate, sodium lauryl sulfate, titanium dioxide, and triethyl citrate. PROTONIX Delayed-Release Tablets (40 mg and 20 mg) complies with USP dissolution test 2.
PROTONIX (pantoprazole sodium) For Delayed-Release Oral Suspension, 40 mg, contains the active ingredient pantoprazole sodium sesquihydrate in the form of enteric-coated granules in unit dose packets. Each unit dose packet contains enteric-coated granules containing 45.1 mg pantoprazole sodium sesquihydrate (equivalent to 40 mg of pantoprazole) with the following
inactive ingredients: crospovidone, hypromellose, methacrylic acid copolymer, microcrystalline cellulose, polysorbate 80, povidone, sodium carbonate, sodium lauryl sulfate, talc, titanium dioxide, triethyl citrate, and yellow ferric oxide.
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
Pantoprazole is a proton pump inhibitor (PPI) that suppresses the final step in gastric acid production by covalently binding to the (H+, K+)-ATPase enzyme system at the secretory surface of the gastric parietal cell. This effect leads to inhibition of both basal and stimulated gastric acid secretion, irrespective of the stimulus. The binding to the (H+, K+)-ATPase results in a duration of antisecretory effect that persists longer than 24 hours for all doses tested (20 mg to 120 mg).
12.2 Pharmacodynamics
PROTONIX (pantoprazole sodium) For Delayed-Release Oral Suspension, 40 mg has been shown to be comparable to PROTONIX (pantoprazole sodium) Delayed-Release Tablets in suppressing pentagastrin-stimulated MAO in patients (n = 49) with GERD and a history of EE. In this multicenter, pharmacodynamic crossover study, a 40 mg oral dose of PROTONIX For Delayed-Release Oral Suspension administered in a teaspoonful of applesauce was compared with a 40 mg oral dose of PROTONIX Delayed-Release Tablets after administration of each formulation once daily for 7 days. Both medications were administered thirty minutes before breakfast. Pentagastrin-stimulated (MAO) was assessed from hour 23 to 24 at steady state.
Antisecretory Activity
Under maximal acid stimulatory conditions using pentagastrin, a dose-dependent decrease in gastric acid output occurs after a single dose of oral (20-80 mg) or a single dose of intravenous (20-120 mg) pantoprazole in healthy volunteers. Pantoprazole given once daily results in increasing inhibition of gastric acid secretion. Following the initial oral dose of 40 mg pantoprazole, a 51% mean inhibition was achieved by 2.5 hours. With once-a-day dosing for 7 days, the mean inhibition was increased to 85%. Pantoprazole suppressed acid secretion in excess of 95% in half of the subjects. Acid secretion had returned to normal within a week after the last dose of pantoprazole; there was no evidence of rebound hypersecretion.
In a series of dose-response studies, pantoprazole, at oral doses ranging from 20 to 120 mg, caused dose-related increases in median basal gastric pH and in the percent of time gastric pH was > 3 and > 4. Treatment with 40 mg of pantoprazole produced significantly greater increases in gastric pH than the 20 mg dose. Doses higher than 40 mg (60, 80, 120 mg) did not result in further significant increases in median gastric pH. The effects of pantoprazole on median pH from one double-blind crossover study are shown in Table 4.
Table 4: Effect of Single Daily Doses of Oral Pantoprazole on Intragastric pH –––––––––—––––––Median pH on day 7—–––––––––––––––––
Time Placebo 20 mg 40 mg 80 mg
0.5 mg/kg/day. In a separate study, a gastric NE-cell tumor without concomitant ECL-cell proliferative changes was observed in 1 female rat following 12 months of dosing with pantoprazole at 5 mg/kg/day and a 9 month off-dose recovery [ see Nonclinical Toxicology (13.1) ].
12.3 Pharmacokinetics
PROTONIX Delayed-Release Tablets are prepared as enteric-coated tablets so that absorption of pantoprazole begins only after the tablet leaves the stomach. Peak serum concentration (Cmax ) and area under the serum concentration time curve (AUC) increase in a manner proportional to oral and intravenous doses from 10 mg to 80 mg. Pantoprazole does not accumulate, and its pharmacokinetics are unaltered with multiple daily dosing. Following oral or intravenous administration, the serum concentration of pantoprazole declines biexponentially, with a terminal elimination half-life of approximately one hour.
In extensive metabolizers with normal liver function receiving an oral dose of the enteric coated 40 mg pantoprazole tablet, the peak concentration (Cmax ) is 2.5 μg/mL; the time to reach the peak concentration (tmax ) is 2.5 h, and the mean total area under the plasma concentration versus time curve (AUC) is 4.8 μg•h/mL (range 1.4 to 13.3 μg•h/mL). Following intravenous administration of pantoprazole to extensive metabolizers, its total clearance is 7.6-14.0 L/h, and its apparent volume of distribution is 11.0-23.6 L.
A single oral dose of PROTONIX For Delayed-Release Oral Suspension, 40 mg, was shown to be bioequivalent when administered to healthy subjects (N = 22) as granules sprinkled over a teaspoonful of applesauce, as granules mixed with apple juice, or mixed with apple juice followed by administration through a nasogastric tube. The plasma pharmacokinetic parameters from a crossover study in healthy subjects are summarized in Table 5.
Table 5: Pharmacokinetics Parameters (mean ± SD) of PROTONIX For Delayed-Release Oral Suspension at 40 mg
Pharmacokinetic Granules in Granules in Apple Granules in Nasogastric Parameters Applesauce Juice Tube
AUC (μg•hr/mL) 4.0 ± 1.5 4.0 ± 1.5 4.1 ± 1. C (^) max (μg/mL) 2.0 ± 0.7 1.9 ± 0.5 2.2 ± 0. T (^) max (hr) a^ 2.0 2.5 2. a (^) Median values are reported for T max.
Absorption
After administration of a single or multiple oral 40 mg doses of PROTONIX Delayed-Release Tablets, the peak plasma concentration of pantoprazole was achieved in approximately 2. hours, and Cmax was 2.5 μg/mL. Pantoprazole undergoes little first-pass metabolism, resulting in an absolute bioavailability of approximately 77%. Pantoprazole absorption is not affected by concomitant administration of antacids.
Administration of PROTONIX Delayed-Release Tablets with food may delay its absorption up to 2 hours or longer; however, the Cmax and the extent of pantoprazole absorption (AUC) are
not altered. Thus, PROTONIX Delayed-Release Tablets may be taken without regard to timing of meals.
Administration of pantoprazole granules, 40 mg, with a high-fat meal delayed median time to peak plasma concentration by 2 hours. With a concomitant high-fat meal, the Cmax and AUC of pantoprazole granules, 40 mg, sprinkled on applesauce decreased by 51% and 29%, respectively. Thus, PROTONIX For Delayed-Release Oral Suspension should be taken approximately 30 minutes before a meal.
Distribution
The apparent volume of distribution of pantoprazole is approximately 11.0-23.6 L, distributing mainly in extracellular fluid. The serum protein binding of pantoprazole is about 98%, primarily to albumin.
Metabolism
Pantoprazole is extensively metabolized in the liver through the cytochrome P450 (CYP) system. Pantoprazole metabolism is independent of the route of administration (intravenous or oral). The main metabolic pathway is demethylation, by CYP2C19, with subsequent sulfation; other metabolic pathways include oxidation by CYP3A4. There is no evidence that any of the pantoprazole metabolites have significant pharmacologic activity.
Elimination
After a single oral or intravenous dose of 14 C-labeled pantoprazole to healthy, normal metabolizer volunteers, approximately 71% of the dose was excreted in the urine, with 18% excreted in the feces through biliary excretion. There was no renal excretion of unchanged pantoprazole.
Geriatric
Only slight to moderate increases in pantoprazole AUC (43%) and Cmax (26%) were found in elderly volunteers (64 to 76 years of age) after repeated oral administration, compared with younger subjects. No dosage adjustment is recommended based on age.
Pediatric
The pharmacokinetics of pantoprazole were studied in children less than 16 years of age in four randomized, open-label clinical trials in pediatric patients with presumed/proven GERD. A pediatric granule formulation was studied in children through 5 years of age, and PROTONIX Delayed-Release Tablets were studied in children older than 5 years.
In a population PK analysis, total clearance increased with increasing bodyweight in a non-linear fashion. The total clearance also increased with increasing age only in children under 3 years of age.
Neonate through 5 years of age
Drug-Drug Interactions
Pantoprazole is metabolized mainly by CYP2C19 and to minor extents by CYPs 3A4, 2D6, and 2C9. In in vivo drug-drug interaction studies with CYP2C19 substrates (diazepam [also a CYP3A4 substrate] and phenytoin [also a CYP3A4 inducer] and clopidogrel), nifedipine, midazolam, and clarithromycin (CYP3A4 substrates), metoprolol (a CYP2D6 substrate), diclofenac, naproxen and piroxicam (CYP2C9 substrates), and theophylline (a CYP1A substrate) in healthy subjects, the pharmacokinetics of pantoprazole were not significantly altered.
Clopidogrel is metabolized to its active metabolite in part by CYP2C19. In a crossover clinical study, 66 healthy subjects were administered clopidogrel (300 mg loading dose followed by 75 mg per day) alone and with pantoprazole (80 mg at the same time as clopidogrel) for 5 days. On Day 5, the mean AUC of the active metabolite of clopidogrel was reduced by approximately 14% (geometric mean ratio was 86%, with 90% CI of 79 to 93%) when pantoprazole was coadministered with clopidogrel as compared to clopidogrel administered alone. Pharmacodynamic parameters were also measured and demonstrated that the change in inhibition of platelet aggregation (induced by 5 μM ADP) was correlated with the change in the exposure to clopidogrel active metabolite. The clinical significance of this finding is not clear.
In vivo studies also suggest that pantoprazole does not significantly affect the kinetics of the following drugs (cisapride, theophylline, diazepam [and its active metabolite, desmethyldiazepam], phenytoin, warfarin, metoprolol, nifedipine, carbamazepine, midazolam, clarithromycin, naproxen, piroxicam, and oral contraceptives [levonorgestrel/ethinyl estradiol]). Dosage adjustment of these drugs is not necessary when they are coadministered with pantoprazole. In other in vivo studies, digoxin, ethanol, glyburide, antipyrine, caffeine, metronidazole, and amoxicillin had no clinically relevant interactions with pantoprazole.
Based on studies evaluating possible interactions of pantoprazole with other drugs, no dosage adjustment is needed with concomitant use of the following: theophylline, cisapride, antipyrine, caffeine, carbamazepine, diazepam (and its active metabolite, desmethyldiazepam), diclofenac, naproxen, piroxicam, digoxin, ethanol, glyburide, an oral contraceptive (levonorgestrel/ethinyl estradiol), metoprolol, nifedipine, phenytoin, warfarin, midazolam, clarithromycin, metronidazole, or amoxicillin.
There was also no interaction with concomitantly administered antacids.
There have been postmarketing reports of increased INR and prothrombin time in patients receiving proton pump inhibitors, including PROTONIX, and warfarin concomitantly [ see Drug Interactions (7.2) ].
Although no significant drug-drug interactions have been observed in clinical studies, the potential for significant drug-drug interactions with more than once-daily dosing with high doses of pantoprazole has not been studied in poor metabolizers or individuals who are hepatically impaired.
Other Effects
In a clinical pharmacology study, PROTONIX 40 mg given once daily for 2 weeks had no effect on the levels of the following hormones: cortisol, testosterone, triiodothyronine (T 3 ), thyroxine (T 4 ), thyroid-stimulating hormone (TSH), thyronine-binding protein, parathyroid hormone, insulin, glucagon, renin, aldosterone, follicle-stimulating hormone, luteinizing hormone, prolactin, and growth hormone.
In a 1-year study of GERD patients treated with PROTONIX 40 mg or 20 mg, there were no changes from baseline in overall levels of T 3 , T 4 , and TSH.
12.4 Pharmacogenomics
CYP2C19 displays a known genetic polymorphism due to its deficiency in some subpopulations (e.g., approximately 3% of Caucasians and African-Americans and 17% to 23% of Asians are poor metabolizers). Although these subpopulations of pantoprazole poor metabolizers have elimination half-life values of 3.5 to 10.0 hours in adults, they still have minimal accumulation (≤ 23%) with once-daily dosing. For adult patients who are CYP2C poor metabolizers, no dosage adjustment is needed.
Similar to adults, pediatric patients who have the poor metabolizer genotype of CYP2C (CYP2C19 2/2) exhibited greater than a 6-fold increase in AUC compared to pediatric extensive (CYP2C19 1/1) and intermediate (CYP2C19 1/x) metabolizers. Poor metabolizers exhibited approximately 10-fold lower apparent oral clearance compared to extensive metabolizers.
For known pediatric poor metabolizers, a dose reduction should be considered.
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
In a 24-month carcinogenicity study, Sprague-Dawley rats were treated orally with doses of 0. to 200 mg/kg/day, about 0.1 to 40 times the exposure on a body surface area basis of a 50 kg person dosed at 40 mg/day. In the gastric fundus, treatment at 0.5 to 200 mg/kg/day produced enterochromaffin-like (ECL) cell hyperplasia and benign and malignant neuroendocrine cell tumors in a dose-related manner. In the forestomach, treatment at 50 and 200 mg/kg/day (about 10 and 40 times the recommended human dose on a body surface area basis) produced benign squamous cell papillomas and malignant squamous cell carcinomas. Rare gastrointestinal tumors associated with pantoprazole treatment included an adenocarcinoma of the duodenum at 50 mg/kg/day and benign polyps and adenocarcinomas of the gastric fundus at 200 mg/kg/day. In the liver, treatment at 0.5 to 200 mg/kg/day produced dose-related increases in the incidences of hepatocellular adenomas and carcinomas. In the thyroid gland, treatment at 200 mg/kg/day produced increased incidences of follicular cell adenomas and carcinomas for both male and female rats.
In a 24-month carcinogenicity study, Fischer 344 rats were treated orally with doses of 5 to 50 mg/kg/day, approximately 1 to 10 times the recommended human dose based on body
