There a number of reasons why a condom should NOT have spermacide. One is a possible allergy, or at least irritation due to the spermicide. The other is that spermicide, in particular the popular nonoxynol-9, has been found to increase the possibility of HIV transmission, despite early claims to the contrary. Therefore, only non-spermacidal condoms and lubricants are now suggested where HIV transmission prevention is a concern, particulary in the case of anal sex. There is now concern that the irritiation caused by N-9 may increase the transmission risk of other STDs as well.
The story with nonoxynol-9 is quite an interesting one. Early on, this spermicide was noted to destroy the HIV virus in the test tube. Therefore, manufacturers of condoms began promoting their nonoxynol-9 treated condoms as being particularly effective barriers against HIV, although no human testing had been done. It was later found that the vaginal irritation caused by the nonoxynol-9 produced entrance pathways for the virus that outweighed the destructive effect. When used for anal sex, the irritation and increased risk is much greater than with vaginal use. Therefore, the original claims turned out to be quite incorrect, and to the contrary, nonoxynol-9 actually increased the risk of HIV transmission, as well as possibly other STDs.
The first studies conducted by the WHO showed modestly increased HIV transmission risk among female prostitutes who were frequently exposed to N-9 (as many as 20 tricks a day). At first, there was little evidence that lesser exposure (for example, once-a-day sex) would pose the same increased risk. However, subsequent research has shown increased risk infection rates of various STDs (not only HIV) in women who are exposed to N-9, although still frequently. Further, it has been discovered that N-9 very rapidly damages rectal tissue. In as little as 15 mintues of exposure, rectal tissue becomes significantly exfoliated, increasing the chance of STD transmission.
Therefore, there is no clear consensus on the use of N-9 for vaginal sex or ordinary frequency. However, it is generally agreed that products containing N-9 should not be used for anal sex.
For a discussion of N-9 provided by the King County (WA) Board of Health, follow this link:
http://www.metrokc.gov/health/apu/infogram...xynol9-0403.htm
From the Canadian Board of Health:
http://www.hc-sc.gc.ca/pphb-dgspsp/publica...onoxynol_e.html
The CDC (
www.cdc.gov) also has a wealth of information about nonoxynol-9, but not as concise as the summaries above.
