Summary Safety Review - Over-the-Counter Products Containing Pseudoephedrine - Assessing the Potential Risk of Inflammation and Injury of the Large Intestine due to Insufficient Blood Supply (ischemic colitis)

February 24, 2016

Product

Over-the-counter products containing pseudoephedrine

Potential Safety Issue

Inflammation and injury of the large intestine due to insufficient blood supply (ischemic colitis)

Key Messages

• Pseudoephedrine is a medicinal ingredient in over-the-counter products that is used to treat the blockage of nasal passages due to excess fluid or mucus (nasal congestion).
• Health Canada carried out a safety review on the potential link between ischemic colitis and the use of pseudoephedrine after a foreign serious case report of ischemic colitis was published in the scientific literature.
• Health Canada's safety review concluded that there is very limited evidence of ischemic colitis with the occasional use of pseudoephedrine in Canada at recommended dose and duration, in the absence of other risk factors. No cases have been reported in Canada. An article will be published in the Health Product InfoWatch regarding this issue to raise awareness and to encourage reporting of ischemic colitis with health products, including pseudoephedrine and other over-the-counter products.

Overview

A safety review was carried out to evaluate the potential link between the use of pseudoephedrine and ischemic colitis. This issue was identified after a serious foreign case report was published in the scientific literature linking ischemic colitis with the use of pseudoephedrine^{Footnote 1}. Ischemic colitis is an inflammation and injury of the large intestine (colon) due to reduced blood flow. Although uncommon in the general population, ischemic colitis occurs with greater frequency in the elderly (age-related reduction in blood flow). This condition may also be linked with other blood vessel problems (hardening of blood vessels, low blood pressure, blood clots), or other conditions that may reduce blood flow to the colon (i.e., blockage, surgery, intense exercise, use of pharmaceutical agents or medications).

Use in Canada

• Pseudoephedrine is a medicinal ingredient in over-the-counter products that is used to treat the blockage of nasal passages due to excess fluid or mucus (nasal congestion).
• These products are generally intended for short-term use. A healthcare practitioner should be consulted for use beyond seven days.
• Pseudoephedrine is one of the most commonly used ingredients in over-the-counter oral nasal decongestants, and can be found either as a single ingredient natural health product, or as a non-prescription combination drug product with other ingredients such as antihistamines, analgesics, or antitussive agents.
• There are more than 200 over-the-counter products containing pseudoephedrine that have been licensed by Health Canada.

Safety Review Findings

• At the time of the review, no Canadian cases of ischemic colitis were reported with the use of pseudoephedrine.
• A review of international data from the World Health Organization's case report database identified 24 cases of ischemic colitis, 7 of which involved the use of single ingredient pseudoephedrine. These 24 cases could not be assessed due to limited information provided.
• A review of the scientific and medical literature identified 9 cases of ischemic colitis associated with the use of pseudoephedrine, 2 cases of which could not be assessed due to limited information.
• Of the remaining 7 published cases, 6 were found to have other contributing risk factors (use of other drugs, pre-existing health conditions, excessive use of pseudoephedrine). Only in 1 recent case report^{Footnote 1}, it was determined by the authors that pseudoephedrine alone was the probable cause of ischemic colitis.

Conclusions and Actions

• Health Canada's safety review concluded that there is very limited evidence of ischemic colitis linked with the occasional use of pseudoephedrine at recommended dose and duration, in the absence of other risk factors. Pseudoephedrine and several other types of medications are known to cause narrowing of blood vessels (vasoconstriction), so a risk of ischemic colitis cannot be ruled out entirely in susceptible people (e.g. those with other underlying conditions, etc.).
• Health Canada will publish an article in the Health Product InfoWatch to raise awareness and to encourage healthcare practitioners to ask their patients about the use of health products containing pseudoephedrine.
• Health Canada will continue to monitor safety information involving pseudoephedrine, as it does for all health products on the Canadian market, to identify and assess potential harms. Health Canada will take appropriate and timely action if and when any new health risks are identified.

Additional Information

The analysis that contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what is known about the use of this drug both in Canada and internationally.

For additional information, contact the Marketed Health Products Directorate.

Reference