First-uterine-pass effect

A number of drug substances are known to act directly upon the uterus, including uterine relaxants (e.g., (3-agonists) and stimulants (e.g., prostanoids, oxytocin). The administration of drugs to the uterus is achieved by the application of a formulated product to the vagina or the cervix. However, it has been demonstrated that the mechanism by which the drug is transported from the cervicovagina to the uterus is not limited to passive diffusion, but is facilitated by a preferential transport mechanism termed as the first uterine pass effect. 

FIGURE 21.5 Illustration of the first uterine pass effect. 

Bulletti, C., et al. 1997. Targeted drug delivery in gynaecology The first uterine pass effect. Hum Reprod 12 1073. 

Cicinelli, E., et al. 2004. First uterine pass effect is observed when estradiol is placed in the upper but not the lower third of the vagina. Fertil Steril 81 1414. 

Bulletti, C., de Ziegler, D., Flamigni, C., Giacomucci, E., Polli, V., Bolelli, G., and Franceschetti, F. (1997), Targeted drug delivery in gynaecology The first uterine pass effect, Hum. Reprod., 12,1073-1079. 

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