%0 Journal Article
%T Vaginal contraceptives still evolving.
%A Pearson RM
%J Netw Res Triangle Park N C
%V 7
%N 2
%D 1986
%M 12340621
暂无%X The effort to develop vaginal contraceptives began in the distant past and is still underway today.  1000 years ago, South American Indians inserted into the vagina bark strips impregnated with quinine.  In medieval times women used vaginal inserts of cloth soaked in honey or vinegar.  Quinine pessaries were introduced into Europe in the late 1800s, and in the early 1900s investigators began to study the effects of various chemicals on sperm motility.  Following World War II, surfactant spermicides which disrupt the sperm membrane were developed and marketed.  Many of these preparations contained nonoxynol-9.  Currently, the D-isomer of propranolol is being examined as a spermicidal contraceptive, and several bacteriocides, e.g., benzalkonium and chlorhexidine, are being developed as spermicides which reduce the penetrability of cervical mucus.  Other chemicals being investigated act by inhibiting the acrosome reaction.  Advantages of vaginal contraceptives are that they are inexpensive, reversible, and relatively safe and easy to use.  Generally they require no medical intervention or supervision.  In addition, spermicides may kill or inhibit the growth of organisms responsible for sexually transmitted diseases.  Disadvantages of spermicides are that they are generally less effective than many other methods, some interfere with sexual spontaneity, they may cause local irritations, and some women find them messy to use.  Recently, concerns were expressed about the possible teratogenic effects of sperimicides.  Most of these concerns proved to be unfounded.  Given the many new avenues of research, the major disadvantage of sperimicides, i.e., their high failure rates, may be minimized in the near future.