RESUMEN
Ectopic pregnancy, that is, a blastocyst occurring outside the endometrial cavity of the uterus, affects nearly 2% of pregnancies. The treatment of ectopic pregnancy is surgical or pharmacological. Since surgical management is associated with numerous serious side effects, conservative treatment is sought. The treatment of choice in the majority of cases is based on pharmacotherapy with methotrexate (MTX) in a single- or multi-dose regimen. Although the efficacy of methotrexate reaches between 70 and 90%, its use requires specific conditions regarding both the general condition of the patient and the characteristic features of the ectopic pregnancy. Moreover, MTX can cause severe adverse effects, including stomatitis, hepatotoxicity and myelosuppression. Therefore, clinicians and researchers are still looking for a less toxic, more effective treatment, which could prevent surgeries as a second-choice treatment. Some studies indicate that other substances might constitute a good alternative to methotrexate in the management of ectopic pregnancies. These substances include aromatase inhibitors, especially letrozole. Another promising substance in EP treatment is gefitinib, an inhibitor of EGFR tyrosine domain which, combined with MTX, seems to constitute a more effective alternative in the management of tubal ectopic pregnancies. Other substances for local administration include KCl and absolute ethanol. KCl injections used in combination with MTX may be used when foetal heart function is detected in cervical ectopic pregnancies, as well as in heterotopic pregnancy treatment. Absolute ethanol injections proved successful and safe in caesarean scar pregnancies management. Thus far, little is known about the use of those substances in the treatment of ectopic pregnancies, but already conducted studies seem to be promising.