Archived – Important Safety Information Regarding Fleet® Phospho-Soda® (Sodium Phosphates Oral Solution) – Johnson & Johnson - Merck

Important Drug Safety Information

March 15, 2002

Important Safety Information Regarding Fleet® Phospho-Soda® (Sodium Phosphates Oral Solution)

Dear Healthcare Professional:

Following discussions with Health Canada, Johnson & Johnson - MERCK Consumer Pharmaceuticals would like to highlight the following important safety information related to the use of Fleet® Phospho-Soda®:

• Electrolyte shifts may occur in patients with or without risk factors for electrolyte shifts if the maximum recommended dose of 45mL (contains 5760 mg phosphorus) in a 24 hour period is exceeded. Hypocalcemia, hyperphosphatemia, hypernatremia, hypokalemia, and acidosis have occurred with the use of sodium phosphates oral solutions. These conditions are more likely to occur when more than one dose (45mL) of sodium phosphates oral solution is given in a 24 hour period. Physicians should counsel patients on the recommended dose.
• The recommended maximum total daily dose for any indication for adults is 45mL of sodium phosphates oral solution in a 24 hour period (contains 5760mg of phosphorus). Do not use the product in patients with congenital megacolon, bowel obstruction, ascites or congestive heart failure.
• Use the product with caution in patients with impaired renal function, heart disease, acute myocardial infarction, unstable angina, pre-existing electrolyte imbalances, patients taking drugs that may affect electrolyte levels, the elderly, or with debilitated patients.
• Treatment of electrolyte imbalance may require immediate medical intervention with appropriate electrolyte and fluid replacement.

Fleet® Phospho-Soda® (Sodium Phosphates Oral Solution) is an oral solution which has been marketed in Canada since 1987 and is used as a laxative for the relief of occasional constipation. The product is also used as a purgative as part of a bowel cleansing regimen in preparing patients for surgery or for preparing the colon for x-ray or endoscopic examination.

Serious electrolyte disturbances (hypocalcemia, hyperphosphatemia, hypernatremia, hypokalemia), dehydration, renal failure, and tetany have been observed :

• in patients ingesting more than 45mL of sodium phosphates oral solution as a bowel preparation for colonoscopy, surgery, or barium enema, at a physician's instruction.
• in patients at medical risk.
• in patients using multiple purgatives for bowel preparation.

These observations were identified through a review of adverse drug reactions associated with sodium phosphates oral solutions received by the Canadian Adverse Drug Reaction Monitoring Program from 1987 up to October 31, 2001. A search of the database revealed 10 domestic Canadian reports with 9 of these reports involving one or more of these risk factors. Reporting rates determined on the basis of spontaneously reported post-marketing adverse events may underestimate the risks associated with drug treatments. For more information, refer to the FDA Science Background document "Safety of sodium phosphates oral solution" (available at http://www.fda.gov/cder/drug/safety/sodiumphospate.htm)

Changes in hematocrit, serum sodium, blood urea nitrogen, serum osmolality, and body weight after ingesting sodium phosphate oral solution suggest that a contraction of intravascular volume can occur. In patients without risk factors, shifts in serum calcium, serum phosphorus, serum sodium, and serum potassium can be statistically significant when compared to baseline values, but generally electrolyte values remain within the normal range without significant clinical sequelae and return to normal values rapidly. The clinical significance of any changes in electrolyte values will be influenced by individual patient risk factors for electrolyte shifts and concurrent medical conditions such as those noted above.

If administration of sodium phosphates oral solution is being considered for patients at risk of electrolyte imbalances or if more than 45mL of the product is to be used in a 24 hour period it is advisable to obtain baseline electrolyte levels prior to administration and to ensure sufficient fluid replacement to prevent dehydration and serious electrolyte problems.

The identification, characterization, and management of drug-related adverse events is dependent on the active participation of health care professionals in adverse drug reaction reporting programmes. Health care professionals are asked to report any suspected adverse reactions in patients receiving Sodium Phosphates Oral Solution (Fleet® Phospho-soda®) directly to Johnson & Johnson o MERCK Consumer Pharmaceuticals at the following address:

Johnson & Johnson - MERCK Consumer Pharmaceuticals
890 Woodlawn Road West
Guelph, ON
N1K 1A5
Tel: 1-888-730-4636
Fax: (519) 826-6205
e-mail: fleet@mcneilcanada.com

Your professional commitment in this regard has an important role in protecting the well-being of your patients by contributing to early signal detection and informed drug use.

Should you have any questions or require additional information concerning the use of Fleet® Phosphosoda®, please contact Johnson & Johnson o MERCK Consumer Pharmaceuticals Health Information Centre at 1-888-730-4636 from 8:00am to 8:00pm, Eastern Standard Time, Monday to Friday.

Sincerely,

original signed by

James H. Swann, M.D., F.R.C.P. ©).
Vice President, Medical

Any suspected adverse drug reactions can also be reported to:

Canadian Adverse Drug Reaction Monitoring Program (CADRMP)
Bureau of Licensed Product Assessment
Therapeutic Products Directorate
Health Canada
Address Locator: 0201C2
Ottawa, Ontario, K1A 1B9
Tel: (613) 957-0337 or Fax: (613) 957-0335
Toll free for consumers and health professionals:
Tel: 866 234-2345, Fax: 866 678-6789
cadrmp@hc-sc.gc.ca

The ADR Reporting Form can be found in The Canadian Compendium of Pharmaceuticals and Specialties, or on the TPD website, along with the ADR Guidelines.