Why consider vaginal drug administration?

OBJECTIVE: To review the anatomy and physiology of the vagina, the merits of vaginal drug administration, and the currently available vaginal drug-administration systems.
DESIGN: Review of basic and clinical research. RESULT(S): Although clinicians commonly use topically administered drugs in the vagina, this route for systemic drug administration is somewhat novel. Experience with a variety of products demonstrates that the vagina is a highly effective site for drug delivery, particularly in women's health. The vagina is often an ideal route for drug administration because it allows for the administration of lower doses, steady drug levels, and less frequent administration than the oral route. With vaginal drug administration, absorption is unaffected by gastrointestinal disturbances, there is no first-pass effect, and use is discreet. Knowledge of anatomy, physiology, histology, and immunology of the vagina should allow clinicians to reassure their patients concerning this mode of delivery. Greater understanding and experience by clinicians should lead to increased use and acceptance of the vagina as a route for drug administration. CONCLUSION(S): The safety and efficacy of vaginal administration have been well established. The vaginal route of drug delivery is acceptable and may even be a preferable route of administration for many drugs, particularly hormones, whether for contraception or postmenopausal estrogen therapy.