ectopic preg, SAB, induced abortion

Question 1

how does methotrexate work?

Answer 1

folic acid antagonist: binds to and competitively inhibits hydrofolate reductase, preventing conversion of dihydrofolic acid to folinic acid which is needed for DNA synthesis

Question 2

candidates for methotrexate

Answer 2

hemodynamic stability
ability to comply with post-treatment monitoring
ideally hCG < 5000
tubal size <3.5 cm
no fetal HB