The MHRA issued the warning after recalls, including in the UK, demonstrated many ‘herbal viagra’ products were adulterated with unauthorized pharma ingredients such as sildenafil, tadalafil, vardenafil or their analogues, or lignocaine.
The agency’s testing revealed 65 per cent of 138 products that went under the microscope since 2005 were tainted with pharma ingredients.
“Quantities varied widely and in some cases amounted to what would be regarded as toxic overdose levels of prescription medicines.”
Major risks
Sildenafil, tadalafil, and vardenafil are authorised as prescription-only drugs to treat erectile dysfunction, but are not permitted in herbal products typically sold via multi-level marketing schemes, the internet and herbal medicine outlets.
“Any product obtained by other means is considered illegal,” the MHRA said. “Consumers are taking major risks if they purchase these products. Consumers should be vigilant and treat any herbal remedy sold for the treatment of erectile dysfunction as a potential health risk and should not purchase the product.”
The products are often branded as 'herbal Viagra' or 'traditional herbal supplements for men' and claim to be 100 per cent natural when they are not.
“Of particular concern is the fact that these analogues have not been subject to the stringent medicines testing process and it is not known if these ingredients are safe to use,” MHRA said.
“Consumption of medicines containing random, uncontrolled quantities of these analogue chemical compounds is especially dangerous and could potentially cause serious adverse reactions such as heart attack, stroke and severe hypotension.”
Recalls
Singapore, the US, Canada, Hong Kong, Australia and the Netherlands have recalled herbal viagra products recently.
The Singapore Health Sciences Authority issued recalls on several products in 2008 after its medical products agency received 240 adverse events including ten deaths related to products tainted with toxic doses of glibenclamide.
The MHRA in April issued a recall when sibutramine, as well as tadalafil, were found in a product called Jia Yi Jian that was marketed as being “100% herbal”, yet each tablet contained 68.1mg of sibutramine and 50.06mg of tadalafil when respective levels of only 15mg and 20mg are permitted in the UK.