Topical anesthetics linked to serious side-effects: Health Canada
Agency also issues warning about using oral sodium phosphate products as bowel cleanser
Serious side-effects such as seizures and difficulty breathing have been reported among people using products that numb the skin before cosmetic procedures such as laser removal of body hair, Health Canada says.
In an advisory released Thursday in collaboration with AstraZeneca Canada Inc. and Smith & Nephew Inc., the department warned of side-effects related to topical anesthetics such as EMLA(R), AMETOP Gel(TM) and locally compounded products.
The reported side-effects include:
- Irregular heartbeat.
- Difficulty breathing.
In rare cases, the side-effects have resulted in deaths.
Topical anesthetics are approved for numbing the skin before vaccinations and minor skin surgery. The products are also being used, often without direct medical supervision, to numb large areas of skin before cosmetic procedures.
Adults who showed the serious side-effects used very large amounts of the topical anesthetics, and then usually covered the area with plastic wrap to boost the effectiveness of the drug.
Air-tight dressings can be used with some topical anesthetics, but consumers who are unsure about how much to use or how to apply it should check with a doctor, pharmacist or other health-care professional.
Serious side-effects are more likely if the products are applied to irritated or broken skin.
Some infants and children who experienced serious side-effects used amounts that were near the recommended dose, the advisory said.
Anyone using a topical anesthetic who shows signs of weakness, confusion, headache, difficulty breathing, discoloured skin or any other sign of being unwell should seek immediate medical attention.
Bowel cleanser warning
In a second advisory released Thursday, Health Canada warned people not to use oral sodium phosphate products as bowel cleansers unless recommended by a health-care practitioner.
The products are currently available over-the-counter as natural health products.
People have safely used oral sodium phosphate as a laxative for years.
But when taken at a purgative dose for bowel cleansing, the products have been associated with serious side-effects, including electrolyte disturbances and kidney injury.
Between Nov. 8, 1994 and Feb. 29, 2008, Health Canada has had more than 50 adverse-reaction reports associated with oral sodium phosphate products in Canada. Of these, 30 involved kidney dysfunction, including 27 reported as serious.
Gastrointestinal symptoms, cardiovascular and neurological problems, and allergic reactions have also been reported.
In Canada, there are three authorized oral sodium phosphate products that have instructions for laxative and purgative use on their labels:
- Phoslax (Odan Laboratories Ltd.; Natural Product Number 80000689).
- Fleet Phospho-Soda Oral Laxative (Johnson & Johnson Merck Consumer Pharmaceuticals; NPN 02206218).
- Phosphate Solution (Pharmascience Inc.; NPN 02230399), which is also sold under the brand names Option + Phosphates Solution, Pharmasave Phosphates Solution and Reserve Phosphates Solution.
Johnson & Johnson said they have voluntarily discontinued the sale of the Fleet Phospho-Soda in Canada.