About 4%–5% of women experience unsuccessful methotrexate treatment and require surgery. hCG, human chorionic gonadotropin; SGOT, serum glutamic-oxaloacetic transaminase; BUN, blood urea nitrogen; CBC, complete blood count; Rho-GAM, Rh0(D) immune globulin; NSAIDs, nonsteroidal anti-inﬂammatory drugs; WBC, white blood cell; PO, by mouth; bid, twice daily.
the administration of methotrexate on day 0 and day 4 with monitoring of β-hCG levels on days 4 and 7. If there is less than a 15% drop between the two measures, a repeat administration of methotrexate is given on days 7 and 11 and β-hCG levels drawn accordingly. A single study showed an 87% success rate with low complication rates and high patient satisfaction (199).
Effectiveness of Methotrexate
The overall effectiveness of methotrexate therapy ranges from 78% to 96% (200). A meta-analysis in 2003 of 26 observational studies including 1,300 women revealed a significantly higher rate (93% versus. 88%) of successful treatment with multidose therapy (194). A meta-analysis comparing two randomized controlled trials showed no difference in success rates between the two regimens; however, the β-hCG levels in both of these studies were less than 3,000 mIU/mL (184,201,202).
When comparing methotrexate to laparoscopic salpingostomy, the multidose regimen has similar success rates. The single-dose regimen has lower initial success rates. After women receive additional doses as needed, the success rates are comparable between laparoscopic salpingostomy and single-dose methotrexate protocols (184).
Initiating Methotrexate Outlined in Table 20.4 is a checklist that should be followed by the physician before initiating methotrexate. It includes instructions that are helpful to the patient.
Patient Follow-Up After intramuscular administration of methotrexate, regardless of the dose regimen used, patients are monitored on an outpatient basis with weekly β-hCG levels. These levels need to be monitored until the β-hCG reaches nonpregnant levels. It is possible that tubal rupture may occur even if β-hCG levels are falling. Signs of a tubal rupture include severe pain, hemodynamic instability, and a drop in hematocrit. Patients who report severe or prolonged pain should be evaluated by measuring hematocrit levels and performing transvaginal ultrasonography. The ultrasonography findings during follow-up, although usually not helpful, can be used to provide reassurance that the tube is not ruptured (203). Cul-de-sac ﬂuid is a common finding, and the amount of ﬂuid may increase if a tubal abortion occurs. It is not necessary to intervene surgically, unless the patient has a precipitous drop in hematocrit levels or she becomes hemodynamically unstable.