ABSTRACT
Barrier methods Barrier methods are again in fashion. In spite of their wellknown disadvantages they all (notably condoms) provide useful protection against sexually transmitted infections. All users of this type of method should be informed about emergency contraception, in case of lack of use or failure in use. Vegetable and oil-based lubricants, and the bases for many prescribable vaginal products, can seriously damage and lead to rupture of rubber: baby oil destroys up to 95% of a condom’s strength within 15 minutes. Beware ad hoc use of substances from the kitchen or bathroom cupboard! Water-based products such as KY jelly, and also glycerine and silicone lubricants, are not suspect. The Durex Information Service has produced a useful leaflet listing common vaginal preparations which should be regarded as unsafe to use with rubber condoms and diaphragms, and there may be others:
Preparations unsafe to use with rubber condoms or diaphragms Arachis oil enema Nizoral Baby oil Nystan cream (pessaries OK) Cyclogest Ortho Dienoestrol Dalacin cream Ortho-Gynest (Ovestin OK) Ecostatin Petroleum jelly Fungilin Premarin cream Gyno-Daktarin Sultrin Gyno-Pevaryl (Pevaryl OK) Vaseline Monistat Witepsol-based preparations
Sheaths or condoms Condoms are the only proven barrier to transmission of HIV, yet at the time of writing it still remains impossible in the UK for most couples to obtain this life-saver free of charge from their GP. Condoms are second in usage to the pill under the age of 30 and to sterilization above that age. One GP has reported a failure rate as low as 0.4/100 woman-years, but 2-15 is more representative. Failure, often unrecognized at the time, can almost always be attributed to incorrect use, mainly through escape of a small amount of semen either before or after intercourse. Conceptions, particularly among the young or those who have become a bit casual after years of using a simple method such as the COC, can sometimes be ‘iatrogenic’, because of lack of explanation by nurse or doctor of the basics.
