A 22-year-old woman has been sexually assaulted. She requests a postcoital contraceptive. Which of the following is the most appropriate drug, assuming no contraindications? (LQ)
|A||Ergonovine (or methylergonovine)|
a. Mifepristone is a synthetic drug used as an abortifacient or postcoital contraceptive.
b. Although the drug blocks glucocorticoid receptors, that effect does not account for its use or effects in the context described here. Here the actions arise from blocking uterine progesterone receptors.
c. They include detachment of the conceptus from the uterine wall, softening and dilation of the cervix, and increased myometrial contraction that expels the conceptus.
d. (The latter arises from both a drug-induced increase of local prostaglandin synthesis and greater myometrial responsiveness to them.
e. If mifepristone fails to induce expulsion of the fetus, misoprostol is usually given to increase uterine contractions further. (Estrogens used alone or in combination with progestins have also proven effective in postcoital contraception.)
f. Ergonovine and methylergonovine are ergot compounds that cause uterine contraction, and are used postpartum to control bleeding by increasing uterine tone.
g. They are abortifacient drugs, but not used for post coital contraception. Raloxifene and tamoxifen are estrogen receptor agonists or antagonists (which effects occurs depends on the tissue) that are used to treat certain estrogen-dependent breast cancers.
h. Ritodrine is a beta 2-adrenergic agonist used to slow uterine contractions and reduce uterine tone in premature labor.
i. Production of ritodrine is several countries have been put on hold because of its large number of cardiac side effects. Atosiban, a drug that blocks oxytoxicin receptors has been taken out of market because the drug lacks efficacy.
j. Calcium channel blockers, in several metanalysis did so far have been the safest drugs for this indication.