Korean study paints alarming picture of risks posed by fake ED drugs

Researchers from Korea have analysed counterfeit versions of drugs used to treat erectile dysfunction to examine the risks patients may be exposed to by taking them, with alarming if not surprising results.

The small study - reported this week at the American Urological Association annual conference in San Francisco, USA - found that most of the counterfeit ED drugs samples contained too much of the active ingredient, with one sample delivering 2.4 times the recommended dose.

All the drugs sampled were copies of phosphodiesterase type 5 inhibitors sold by Pfizer Pharmaceutical Korea's (Viagra; sildenafil) and Lilly Korea (Cialis; tadalafil), and were acquired from adult shops or online.

The aim of the study was to analyse chemically counterfeit PDE5 inhibitors "to evaluate threat or harmfulness to patients due to toxic materials or improper erectogenic materials," according to the researchers, who compared their samples with genuine product obtained from the manufacturers.

A total of 19 fake products were identified, with a third of them varying in size and 42 per cent varying in colour from the genuine article, suggesting that a trained healthcare provider should be able to identify them as counterfeit fairly easily.

Only one of the samples actually obtained the correct API in the correct quantity. 58 per cent of samples had excess amounts of API, and 37 per cent had no active at all. Where an API was present, this was often an unapproved analogue of the PDE5 inhibitor, such as homo-sildenafil, hongdenafil, amino-tadalfil, xantho-anthrafil and pseudo-vardenafil, according to the researchers.

One sample contained lead, and four others were contaminated with mercury, which could pose serious health risks.

"Counterfeit PDE5 inhibitors could not be expected [to provide] consistent efficacy by lack of proper active ingredients and could be administered as overdose, which might induce serious side effects," said the researchers.