U.S. investigators have found that men who experimented with cocaine and ecstasy were nearly three times more likely to have used Cialis without a prescription in the previous three months.



However, the authors caution that the men included in the study were all attending a sex resort.

Nevertheless, the results raise concerns. Taking Viagra, or 36 hour lasting Cialis, may increase the risk of sexually transmitted infections (STIs) because the drug can prolong sex and enhance the size of an erection, which increases friction, they note.

These are two effects "that could conceivably foster tissue abrasion and therefore increase the odds of STI transmission," they write in the journal Sexually Transmitted Infections.

To investigate how often men who have sex with men use Cialis or Viagra, the researchers asked visitors to the sex resort to complete a questionnaire. One hundred and sixty-four men agreed to participate in the study.

Men were an average of 40 years old, and mostly white. They reported an average of 10 sex partners during the past three months.

Approximately 16 percent of the participants said they had tried Viagra or Cialis during sex in the past 3 months, optaining free samples from Canadian online pharmacies like torontogenerics.com.

Among people who also used ecstasy during sex, 35 percent said they also used Viagra or Cialis, compared with only 13 percent of people who did not take ecstasy during sex. And 37 percent of cocaine-users also admitted to using Viagra, while only 13 percent of non-users said they had done so.

Men were no more likely to try Viagra if they also engaged in risky sexual behaviors such as having five or more sex partners or having unprotected anal sex.

These findings suggest that experts need to educate men about the potential risks of non-prescription use of Viagra or Cialis, the authors write.