Methotrexate for treatment of ectopic pregnancy is administered by which route and at what dose?

Methotrexate Therapy for Primary Treatment of Ectopic Pregnancy: Regimen Surveillance Single Dose Methotrexate, 50 mg/m2 IM Measure b-hCG levels days 4 and 7: If difference >= 15 percent, repeat weekly until undetectable If differences < 15 percent between day 4 and 7 levels, repeat methotrexate dose and begin from day 1 If fetal cardiac activity present day 7, repeat methotrexate dose, begin from day 1 Surgical treatment if b-hCG levels not decreasing or Fetal cardiac activity persists after three doses methotrexate Multiple dose Methotrexate, 50 mg/m2 IM, days 0,4 Variable dose (up to four doses): Methotrexate, 1 mg /kg IM, days 1,3,5,7 Leucovorin, 0.1 mg/kg IG, days 2,4,6,8 Follow up for single dose regimen Measure b hCG levels day 1,3,5, and 7. Continue alternate - day injections until b hCG levels decreases >= 15 % in 48 hours or four doses of methotrexate. Then, weekly b-hCG until undetectable.