Visicol Side Effects, and Drug Interactions - Sodium phosphate monobasic monohydrate

Visicol Side Effects, and Drug Interactions - Sodium phosphate monobasic monohydrate

SIDE EFFECTS

The most commonly observed adverse reactions (incidence 1%, all treated patients) occurring with the use of Visicol Tablets are related to the desired purgative effect. Nausea, vomiting, abdominal bloating, abdominal pain, dizziness, and headache occur, and are generally transient and self-limited, requiring no specific treatment. All of these adverse events also occurred in patients who took the PEG-salt solution comparator. Small superficial mucosal ulcerations, typical of those previously reported from the use of liquid preparations of sodium phosphate, and instances of mucosal bleeding have been observed on colonoscopy.

One patient, with no history of heart disease, developed an initial episode of atrial fibrillation after severe vomiting immediately after taking Visicol Tablets. Another patient, with known arteriosclerotic heart disease, who took the PEG-salt solution comparator developed atrial fibrillation and also vomited. No patient in the clinical studies developed predefined postural changes in vital signs with concomitant symptoms of lightheadedness or syncope.

Serum electrolyte changes have been observed in patients taking Visicol Tablets, primarily affecting calcium, phosphate, and potassium. These changes essentially corrected within 48 to 72 hours after dosing, were not associated with any clinical adverse events and did not require treatment. No patient developed clinically significant hypocalcemia; among patients receiving Visicol 60 grams (n=481) the mean decrease from baseline in calcium level was 0.5 mg/dl. No patient developed a calcium level below 7.1 mg/dL. No clinical adverse events suggestive of hypocalcemia were observed. Mean serum phosphorus levels increased by approximately 3.6 mg/dL transiently after taking Visicol Tablets with no apparent clinical significance. A reactive decrease in serum phosphorus 2-3 days after dosing was observed; the mean decrease from baseline at that time was 0.7 mg/dL. The mean decrease in serum potassium after taking Visicol Tablets was 0.5 mEq/L.

Under the direction of a physician, Visicol Tablets are indicated for cleansing of the bowel when required as a preparation for colonoscopy, in adults 18 years of age or older. Laxatives and purgatives as a group have the potential for abuse by persons with eating disorders who "binge" and "purge".

Medications administered in close proximity to Visicol may not be absorbed from the gastrointestinal tract due to the rapid intestinal peristalsis and watery diarrhea induced by the purgative agent.

Because of the mechanism of action of Visicol Tablets, patients should be advised to take only clear liquids by mouth for at least 12 hours prior to starting the purgative regimen.

Long-term studies in animals have not been performed to evaluate the carcinogenic potential of Visicol. Studies to evaluate the effect of Visicol on fertility or its mutagenic potential have not been preformed.

Category C. Reproduction studies have not been conducted with Visicol. It is also not known whether Visicol can cause fetal harm when administered to a pregnant woman, or can affect reproduction capacity. Visicol should be given to a pregnant woman only if clearly needed.

Safety and efficacy of Visicol Tablets have not been demonstrated for patients less than 18 years of age.

Of the total number of subjects in clinical studies of Visicol Tablets, 27.7 percent were over 65, while 8.3% percent were over 75. No overall differences in safety or effectiveness were observed between these subjects and younger subjects. However, greater sensitivity of some older individuals cannot be ruled out. Visicol Tablets should be used with caution in elderly patients.

Sodium phosphate is known to be substantially excreted by the kidney, and the risk of adverse reactions with sodium phosphate may be greater in patients with impaired renal function. Elderly patients are more likely to have impaired renal function, and it may be useful to assess renal function.