2.1 Dosage and Adminstration Overview

Administration of two bottles of sodium sulfate, potassium sulfate and magnesium sulfate oral solution and additional water is required for a complete preparation for colonoscopy. One bottle of sodium sulfate, potassium sulfate and magnesium sulfate oral solution is equivalent to one dose. Sodium sulfate, potassium sulfate and magnesium sulfate oral solution is supplied in two dosage strengths [see Dosage Forms and Strengths (3)]. The recommended dosage is:

• Adults : Two 6-ounce doses [see Dosage and Administration (2.3)] .
• Pediatric patients 12 years of age and older: Two 4.5-ounce doses [see Dosage and Administration (2.4)] .

2.2 Important Preparation and Administration Instructions

• Correct fluid and electrolyte abnormalities before treatment with sodium sulfate, potassium sulfate and magnesium sulfate oral solution [see Warnings and Precautions (5.1)]
• Must dilute sodium sulfate, potassium sulfate and magnesium sulfate oral solution in water before ingestion.
• Must consume additional water after each dose of sodium sulfate, potassium sulfate and magnesium sulfate oral solution.
• On the day before colonoscopy, consume only a light breakfast or clear liquids (e.g., water, strained fruit juice without pulp, lemonade, plain coffee or tea, chicken broth, gelatin dessert without fruit). On the day of the colonoscopy only consume clear liquids up to two hours prior to colonoscopy.
• Do not eat solid food or drink milk or eat or drink anything colored red or purple.
• Do not drink alcohol.
• Do not take other laxatives while taking sodium sulfate, potassium sulfate and magnesium sulfate oral solution.
• Do not take oral medications within one hour of starting each dose of sodium sulfate, potassium sulfate and magnesium sulfate oral solution.
• If taking tetracycline or fluoroquinolone antibiotics, iron, digoxin, chlorpromazine, or penicillamine, take these medications at least 2 hours before and not less than 6 hours after administration of sodium sulfate, potassium sulfate and magnesium sulfate oral solution [see Drug Interactions (7.2)] .
• Stop consumption of all fluids at least 2 hours prior to the colonoscopy.

2.3 Recommended Dosage and Administration in Adults

The recommended Split-Dose (two-day) regimen for adults consists of two 6-ounce doses of sodium sulfate, potassium sulfate and magnesium sulfate oral solution: the first dose during the evening prior to colonoscopy and the second dose the next day, during the morning of the colonoscopy.

Each dose consists of one bottle of sodium sulfate, potassium sulfate and magnesium sulfate oral solution with additional water. The total volume of liquid required for colon cleansing (using two bottles) is 3 quarts. The following are recommended dosage and administration instructions for adults:

Dose 1 – On the Day Prior to Colonoscopy:

• May consume a light breakfast, or only clear liquids (no solid food).
• In the evening before the procedure, pour the contents of one bottle of sodium sulfate, potassium sulfate and magnesium sulfate oral solution into the mixing container provided.
• Add cool drinking water to the 16-ounce fill line on the container, mix, and drink the entire amount.
• Drink two additional containers filled with water to the 16-ounce fill line over the next hour.

Dose 2 - Day of Colonoscopy:

• Continue to consume only clear liquids.
• In the morning (10 to 12 hours after the evening dose) on the day of the procedure, pour the contents of the second bottle of sodium sulfate, potassium sulfate and magnesium sulfate oral solution into the mixing container provided.
• Add cool drinking water to the 16-ounce fill line on the container, mix, and drink the entire amount.
• Drink two additional containers filled with water to the 16-ounce fill line over the next hour.
• Complete all solution of sodium sulfate, potassium sulfate and magnesium sulfate oral solution and required water at least two hours prior to colonoscopy.

2.4 Recommended Dosage and Administration in Pediatric Patients 12 Years of Age and Older

The recommended Split-Dose (two-day) regimen for pediatric patients 12 years of age and older consists of two 4.5-ounce doses of sodium sulfate, potassium sulfate and magnesium sulfate oral solution: the first dose during the evening prior to colonoscopy and the second dose the next day, during the morning of the colonoscopy.

Each dose consists of one bottle of sodium sulfate, potassium sulfate and magnesium sulfate oral solution with additional water. The total volume of liquid required for colon cleansing (using two bottles) is 2.25 quarts. The following are recommended dosage and administration instructions for pediatric patients 12 years of age and older and/or their caregivers:

Dose 1 – On the Day Prior to Colonoscopy:

• May consume a light breakfast, or only clear liquids (no solid food).
• In the evening before the procedure, pour the contents of one bottle of sodium sulfate, potassium sulfate and magnesium sulfate oral solution into the mixing container provided.
• Add cool drinking water to the 12-ounce fill line on the container, mix, and drink the entire amount.
• Drink two additional containers filled with water to the 12-ounce fill line over the next hour.

Dose 2 – Day of Colonoscopy:

• Continue to consume only clear liquids.
• In the morning (10 to 12 hours after the evening dose) on the day of the procedure, pour the contents of the second bottle of sodium sulfate, potassium sulfate and magnesium sulfate oral solution into the mixing container provided.
• Add cool drinking water to the 12-ounce fill line on the container, mix, and drink the entire amount.
• Drink two additional containers filled with water to the 12-ounce fill line over the next hour.
• Complete all solution of sodium sulfate, potassium sulfate and magnesium sulfate oral solution and required water at least two hours prior to colonoscopy.

5.1 Serious Fluid and Serum Chemistry Abnormalities

Advise all patients to hydrate adequately before, during, and after the use of sodium sulfate, potassium sulfate and magnesium sulfate oral solution. If a patient develops significant vomiting or signs of dehydration after taking sodium sulfate, potassium sulfate and magnesium sulfate oral solution, consider performing post-colonoscopy lab tests (electrolytes, creatinine, and BUN).

Fluid and electrolyte disturbances can lead to serious adverse events including cardiac arrhythmias, seizures and renal impairment. Correct fluid and electrolyte abnormalities before treatment with sodium sulfate, potassium sulfate and magnesium sulfate oral solution. Use sodium sulfate, potassium sulfate and magnesium sulfate oral solution with caution in patients with conditions, or who are using medications, that increase the risk for fluid and electrolyte disturbances or may increase the risk of adverse events of seizure, arrhythmias, and renal impairment [see Drug Interactions (7.1)].

Sodium sulfate, potassium sulfate and magnesium sulfate oral solution can cause temporary elevations in uric acid. [See Adverse Reactions (6.1)]. Uric acid fluctuations in patients with gout may precipitate an acute flare. The potential for uric acid elevation should be considered before administering sodium sulfate, potassium sulfate and magnesium sulfate oral solution to patients with gout or other disorders of uric acid metabolism.

5.2 Cardiac Arrhythmias

There have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Use caution when prescribing sodium sulfate, potassium sulfate and magnesium sulfate oral solution for patients at increased risk of arrhythmias (e.g., patients with a history of prolonged QT, uncontrolled arrhythmias, recent myocardial infarction, unstable angina, congestive heart failure, or cardiomyopathy). Consider pre-dose and post-colonoscopy ECGs in patients at increased risk of serious cardiac arrhythmias.

5.3 Seizures

There have been reports of generalized tonic-clonic seizures and/or loss of consciousness associated with use of bowel preparation products in patients with no prior history of seizures. The seizure cases were associated with electrolyte abnormalities (e.g., hyponatremia, hypokalemia, hypocalcemia, and hypomagnesemia) and low serum osmolality. The neurologic abnormalities resolved with correction of fluid and electrolyte abnormalities.

Use caution when prescribing sodium sulfate, potassium sulfate and magnesium sulfate oral solution for patients with a history of seizures and in patients at increased risk of seizure, such as patients taking medications that lower the seizure threshold (e.g., tricyclic antidepressants), patients withdrawing from alcohol or benzodiazepines, or patients with known or suspected hyponatremia [see Drug Interactions (7.1)].

5.4 Use in Patients with Risk of Renal Injury

Use sodium sulfate, potassium sulfate and magnesium sulfate oral solution with caution in patients with impaired renal function or patients taking concomitant medications that may affect renal function (such as diuretics, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, or non-steroidal anti-inflammatory drugs) [see Drug Interactions (7.1)]. These patients may be at risk for renal injury. Advise these patients of the importance of adequate hydration with sodium sulfate, potassium sulfate and magnesium sulfate oral solution and consider performing baseline and post-colonoscopy laboratory tests (electrolytes, creatinine, and BUN) in these patients [see Use in Specific Populations (8.6)].

5.5 Colonic Mucosal Ulcerations and Ischemic Colitis

Osmotic laxative products may produce colonic mucosal aphthous ulcerations, and there have been reports of more serious cases of ischemic colitis requiring hospitalization. Concurrent use of stimulant laxatives and sodium sulfate, potassium sulfate and magnesium sulfate oral solution may increase these risks [see Drug Interactions (7.3)]. Consider the potential for mucosal ulcerations resulting from the bowel preparation when interpreting colonoscopy findings in patients with known or suspect inflammatory bowel disease (IBD).

5.6 Use in Patients with Significant Gastrointestinal Disease

If gastrointestinal obstruction or perforation is suspected, perform appropriate diagnostic studies to rule out these conditions before administering sodium sulfate, potassium sulfate and magnesium sulfate oral solution. [see Contraindications (4)].

Use with caution in patients with severe active ulcerative colitis.

5.7 Aspiration

Patients with impaired gag reflex or other swallowing abnormalities are at risk for regurgitation or aspiration of sodium sulfate, potassium sulfate and magnesium sulfate oral solution. Observe these patients during administration of sodium sulfate, potassium sulfate and magnesium sulfate oral solution. Use with caution in these patients.

The following important adverse reactions for bowel preparations are described elsewhere in the labeling:

•   Serious Fluid and Serum Chemistry Abnormalities [see Warnings and Precautions (5.1)]
•   Cardiac Arrhythmias [see Warnings and Precautions (5.2)]
•   Seizures [see Warnings and Precautions (5.3)]
•   Use in Patients with Risk of Renal Injury [see Warnings and Precautions (5.4)]
•   Colonic Mucosal Ulceration and Ischemic Colitis [see Warnings and Precautions (5.5)]
•   Patients with Significant Gastrointestinal Disease[see Warnings and Precautions (5.6)]
•   Aspiration [see Warnings and Precautions (5.7)]  

6.1 Clinical Trials Experience

Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in clinical studies of another drug and may not reflect the rates observed in practice.

Adults

The safety of sodium sulfate, potassium sulfate and magnesium sulfate oral solution was evaluated in a multi-center, randomized, active controlled trial in 379 adult patients undergoing colonoscopy [see Clinical Studies (14)].

Most Common Adverse Reactions

Table 1 shows the most common adverse reactions reported in at least 2% of patients receiving sodium sulfate, potassium sulfate and magnesium sulfate oral solution or the control (a bowel prep containing polyethylene glycol and electrolytes (PEG + E)) administered in split-dose (2-day) regimens.

Laboratory Abnormalities

Table 2 shows the most common laboratory abnormalities (at least 10% in either treatment group and more than 2% difference between groups) for patients who developed new abnormalities of important electrolytes and uric acid after completing the bowel preparation with either sodium sulfate, potassium sulfate and magnesium sulfate oral solution or PEG+E administered as a split-dose (2-day) regimen.    

Table 2: Adult Patients with Normal Baseline Serum Chemistry with A Shift to an Abnormal Value While on the Split-Dose (2-Day) Regimen 1

Less Common Adverse Reactions

AV Block (1 case) and CK increase.

Adverse Reactions with Unapproved Use

In another study of 408 adult patients, higher rates of the following adverse reactions and laboratory abnormalities were reported in patients treated with sodium sulfate, potassium sulfate and magnesium sulfate oral solution as an evening-only (1-day) regimen compared to the split-dose (2-day) regimen.

• overall discomfort, abdominal distention, nausea, and vomiting
• total bilirubin (high), BUN (high), creatinine (high), osmolality (high), potassium (high) and uric acid (high)

Administration of sodium sulfate, potassium sulfate and magnesium sulfate oral solution in an evening-only (1-day) dosing regimen is not recommended.

Pediatrics 12 Years to 16 Years of Age

The safety of sodium sulfate, potassium sulfate and magnesium sulfate oral solution was evaluated in a single dose-ranging clinical trial of 89 pediatric patients aged 12 years to 16 years [see Clinical Studies (14)]. In 26 pediatric patients who received sodium sulfate, potassium sulfate and magnesium sulfate oral solution (two 4.5-ounce doses), the most common adverse reactions (> 10%) were nausea, abdominal pain, abdominal bloating, and vomiting.

7.1 Drugs That May Increase Risks of Fluid and Electrolyte Abnormalities

Use caution when prescribing sodium sulfate, potassium sulfate and magnesium sulfate oral solution to patients taking medications that increase the risk of fluid and electrolyte disturbances or may increase the risk of adverse events of seizure, arrhythmias, and prolonged QT in the setting of fluid and electrolyte abnormalities [see Warnings and Precautions (5.1, 5.2, 5.3, 5.4)].         

7.2 Potential for Reduced Drug Absorption

Sodium sulfate, potassium sulfate and magnesium sulfate oral solution can reduce the absorption of other co-administered drugs [see Dosage and Administration (2.1)].      

• Administer oral medications at least one hour before starting each dose of sodium sulfate, potassium sulfate and magnesium sulfate oral solution.
• Administer tetracycline and fluoroquinolone antibiotics, iron, digoxin, chlorpromazine, and penicillamine at least 2 hours before and not less than 6 hours after administration of sodium sulfate, potassium sulfate and magnesium sulfate oral solution to avoid chelation with magnesium.

7.3 Stimulant Laxatives

Concurrent use of stimulant laxatives and sodium sulfate, potassium sulfate and magnesium sulfate oral solution may increase the risk of mucosal ulceration or ischemic colitis. Avoid use of stimulant laxatives (e.g., bisacodyl, sodium picosulfate) while taking sodium sulfate, potassium sulfate and magnesium sulfate oral solution [see Warnings and Precautions (5.5)].

8.1 Pregnancy

Risk Summary

There are no available data on sodium sulfate, potassium sulfate and magnesium sulfate oral solution use in pregnant women to evaluate for a drug associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Animal reproductive studies have not been conducted with sodium sulfate, potassium sulfate, and magnesium sulfate (sodium sulfate, potassium sulfate and magnesium sulfate oral solution).

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

8.2 Lactation

Risk Summary

There are no data available data on the presence of sodium sulfate, potassium sulfate and magnesium sulfate oral solution in human or animal milk, the effects on the breastfed child, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for sodium sulfate, potassium sulfate and magnesium sulfate oral solution and any potential adverse effects on the breastfed child from sodium sulfate, potassium sulfate and magnesium sulfate oral solution or from the underlying maternal condition.

8.4 Pediatric Use

The safety and effectiveness of sodium sulfate, potassium sulfate and magnesium sulfate oral solution (two 4.5-ounce doses) have been established for cleansing of the colon as a preparation for colonoscopy in pediatric patients 12 years of age and older. Use of sodium sulfate, potassium sulfate and magnesium sulfate oral solution in this age group is supported by evidence from an adequate and well-controlled trial of sodium sulfate, potassium sulfate and magnesium sulfate oral solution in adults and a single, dose-ranging, controlled trial in 89 pediatric patients 12 years to 16 years of age [see Clinical Studies ( 14)] . In the pediatric trial, sodium sulfate, potassium sulfate and magnesium sulfate oral solution (two 6-ounce doses) did not demonstrate additional treatment benefit and more patients reported gastrointestinal adverse reactions compared to sodium sulfate, potassium sulfate and magnesium sulfate oral solution (two 4.5-ounce doses). Therefore, sodium sulfate, potassium sulfate and magnesium sulfate oral solution (two 6-ounce doses) is not recommended for pediatric patients 12 years of age and older [see Dosage and Administration (2.3)]. The safety profile of sodium sulfate, potassium sulfate and magnesium sulfate oral solution (two 4.5-ounce doses) in this pediatric population was similar to that seen in adults [see Adverse Reactions (6.1)].

The safety and effectiveness of sodium sulfate, potassium sulfate and magnesium sulfate oral solution in pediatric patients less than 12 years of age have not been established.

8.5 Geriatric Use

Of the 375 patients who received sodium sulfate, potassium sulfate and magnesium sulfate oral solution in clinical trials, 94 (25%) were 65 years of age or older, and 25 (7%) were 75 years of age or older. No overall differences in safety or effectiveness of sodium sulfate, potassium sulfate and magnesium sulfate oral solution administered as the recommended split-dose (2-day) regimen were observed between geriatric patients and younger patients. Geriatric patients reported more vomiting when sodium sulfate, potassium sulfate and magnesium sulfate oral solution was given as a one-day preparation (not a recommended regimen). Elderly patients are more likely to have decreased hepatic, renal or cardiac function and may be more susceptible to adverse reactions resulting from fluid and electrolyte abnormalities [see Warnings and Precautions (5.1)].

8.6 Renal Impairment

Use sodium sulfate, potassium sulfate and magnesium sulfate oral solution with caution in patients with renal impairment or patients taking concomitant medications that may affect renal function. These patients may be at risk for renal injury. Advise these patients of the importance of adequate hydration before, during and after use of sodium sulfate, potassium sulfate and magnesium sulfate oral solution and consider performing baseline and post-colonoscopy laboratory tests (electrolytes, creatinine, and BUN) in these patients [see Warnings and Precautions (5.4)].

12.1 Mechanism of Action

Sulfate salts provide sulfate anions, which are poorly absorbed. The osmotic effect of unabsorbed sulfate anions and the associated cations causes water to be retained within the gastrointestinal tract.

12.2 Pharmacodynamics

No formal pharmacodynamic studies have been conducted with sodium sulfate, potassium sulfate and magnesium sulfate oral solution.

12.3 Pharmacokinetics

Absorption and Elimination

After administration of sodium sulfate, potassium sulfate and magnesium sulfate oral solution in six healthy subjects, the time at which serum sulfate reached its highest point (Tmax) was approximately 17 hours after the first dose or approximately 5 hours after the second dose, and then declined with a half-life of 8.5 hours.

Excretion

Fecal excretion was the primary route of sulfate elimination.

Specific Populations

Patients with Renal Impairment

The disposition of sulfate after ingestion of sodium sulfate, potassium sulfate and magnesium sulfate oral solution was studied in patients (N=6) with moderate renal impairment (creatinine clearance of 30 to 49 mL/min). In patients with moderate renal impairment, mean AUC was 54% higher and mean Cmax was 44% higher, than healthy subjects.

The mean sulfate concentrations in healthy subjects and in patients with moderate renal impairment returned to their respective baselines by Day 6 after dose initiation. Urinary excretion of sulfate over 30 hours after the first dose was approximately 16% lower in patients with moderate renal impairment than in healthy subjects. These differences are not considered clinically meaningful.

Patients with Hepatic Impairment

The disposition of sulfate after ingestion of sodium sulfate, potassium sulfate and magnesium sulfate oral solution was studied in patients (N=6) with mild to moderate hepatic impairment (Child-Pugh grades A and B). Systemic exposure of serum sulfate (AUC and Cmax) was similar between healthy subjects and patients with hepatic impairment. The mean sulfate concentrations in healthy subjects and in patients with mild to moderate hepatic impairment returned to their respective baselines by Day 6 after dose initiation. Urinary excretion of sulfate over 30 hours after the first dose was similar between patients with hepatic impairment and healthy subjects.

13.2 Animal Toxicology and/or Pharmacology

The sulfate salts of sodium, potassium, and magnesium contained in sodium sulfate, potassium sulfate and magnesium sulfate oral solution were administered orally (gavage) to rats and dogs up to 28 days up to a maximum daily dose of 5 grams/kg/day (approximately 0.9 and 3 times for rats and dogs, respectively, the recommended human dose of 44 grams/day or 0.89 grams/kg based on the body surface area). In rats, the sulfate salts caused diarrhea and electrolyte and metabolic changes, including hypochloremia, hypokalemia, hyponatremia, lower serum osmolality, and high serum bicarbonate. Significant renal changes included increased fractional sodium excretion, increased urinary sodium and potassium excretion, and alkaline urine in both males and females. In addition, creatinine clearance was significantly decreased in females at the highest dose. No microscopic renal changes were seen. In dogs, the sulfate salts caused emesis, excessive salivation, excessive drinking of water, and abnormal excreta (soft and/or mucoid feces and/or diarrhea) and increased urine pH and sodium excretion.