Evaluation of Letrozole and Methotrexate in the Management of Ectopic Pregnancy - A Randomized Clinical Trial Study

Ectopic pregnancy (EP) is one of the critical health conditions worldwide. Letrozole, an aromatase inhibitor that suppresses peripheral conversion of androgens to estrogens, has recently been introduced as a low-cost and minimal side effects treatment for EP. We studied the use of the letrozole for the treatment of EP in comparison with methotrexate.

This double-blind randomized clinical trial was conducted on 40 women with uncomplicated EP (into two groups of 20). The letrozole group received a daily regimen of 5 mg tablets for a duration of 10 days, while the methotrexate group received treatment via a single intramuscular injection of 50 mg/m² of body surface area.

The mean of aspartate aminotransferase (AST), alanine aminotransferase (ALT), hemoglobin, and serum creatinine on the first and seventh days of treatment had no significant difference between the two groups (P > 0.05). Although a significant decrease in beta human chorionic gonadotropin level was found in each of the two groups over time (P < 0.001), there was no significant difference between the two groups on each of the fourth, seventh, and fourteenth days (P > 0.05). The level of anti-mullerian hormone in the methotrexate group with a mean of 2.22 ± 1.23 ng/mL was insignificantly higher than that of the letrozole group with a mean of 1.88 ± 0.89 ng/mL (P = 0.425). The success rate of treatment in methotrexate group was 85%, and that in letrozole group was 70%, However, the difference between the two groups was not significant (P = 0.282).

According to the results of this study, the biochemical and hematological parameters and success treatment rate did not differ significantly between the administration of letrozole and methotrexate. Due to the occurrence of fewer side effects (although insignificant) in the administration of letrozole, it may be possible to introduce this drug as safer and less invasive than methotrexate.