An update on the medical treatment of ectopic pregnancy.

Medical treatment of ectopic pregnancy with methotrexate has been shown to be effective and safe in appropriate patients. When considering medical management, the definitive diagnosis of an ectopic pregnancy and the assurance that the patient is a candidate are of paramount concern. An understanding of the mechanism of action and pharmacokinetics of methotrexate allows the clinician to better inform patients, recognize and treat side effects, and be cognizant when treatment is unsuccessful. Two common protocols, the "multi-dose" and the "single-dose" protocols, have excellent success rates; however, neither one of these is completely effective. The "multi-dose" protocol appears to have a higher success rate than the "single-dose" protocol.