(CP) - Health Canada is warning consumers against taking certain unauthorized natural health products promoted for the treatment of erectile dysfunction because they contain pharmaceutical ingredients that should be used only under medical supervision.
The products - Zimaxx, Actra-Rx, 4Everon, Vigor-25 and Nasutra - could pose serious health risks, especially for people with heart disease, those taking heart medications or those at risk for stroke.
Although not authorized for sale in Canada, Zimaxx, Actra-Rx, 4Everon, Vigor-25 and Nasutra are or may have been sold over the Internet or brought into Canada by travellers for personal use, Health Canada said in an advisory Thursday.
Zimaxx is adulterated with sildenafil, the active pharmaceutical ingredient found in the prescription drug Viagra. Actra-Rx, 4Everon and Nasutra contain modified forms of sildenafil. Vigor-25 is contaminated with a modified form of vardenafil, the active in the prescription drug Levitra.
Use of any of the products could cause serious side-effects, including sudden vision loss, increased heart rate, decreased blood pressure, penile tissue damage, permanent loss of potency and urinary tract infections. Other less serious side-effects may include indigestion, headaches, flushing and dizziness.
"The use of these products can also produce a specific type of vision loss called non-arteritic anterior ischemic optic neuropathy in people over the age of 50 years and in those with risk factors such as high blood pressure, high cholesterol, diabetes, smoking or those with a blood vessel problem in the eye that can lead to stroke," said Health Canada. "This condition can be irreversible."
Products containing sildenafil or vardenafil should not be used by anyone taking a nitrate medication because the combination could lead to potentially life-threatening low blood pressure.
To date, no adverse reactions suspected to be associated with the use of any of these products has been reported.
A previous Health Canada warning was issued for Nasutra in May because the product was found to contain sildenafil. Nasutra has since been found to contain a modified form of the drug.
Consumers taking any of these five products should stop their use immediately and consult a doctor if they have concerns about their health, the federal agency advised.