The condom should be made of latex and must be used properly. Natural skin
condoms have been shown to leak in laboratory studies, whereas latex condoms
maintain their integrity and are more durable. Nonoxynol-9, a spermicide
with some antiviral activity, enhances the protective effects of condoms and
should be used in conjunction with condoms either as a spermicidal jelly or
impregnated into the latex condom itself. Petroleum-based lubricants enhance
the likelihood of latex condom rupture and should be avoided. If needed,
water-based lubricants such as K-Y jelly should be used. Both partners
should be knowledgeable about the correct use of condoms. Discussions
regarding condom use should occur before the need arises, and ideally,
condom placement should be practiced in advance. A new condom should be used
for each act of intercourse and each condom should be used only one time.
Even under the best of circumstances, a 5 to 15 per cent failure rate has
been noted among couples using condoms as their sole means of contraception,
and HIV transmission has been reported in discordant couples using condoms.
Condom ineffectiveness is most often due to improper placement, falling off
during intercourse, and rupture. Therefore, while condom use during
intercourse is considered "safer" sex, it is not absolutely safe.