What is the leucovorin dose in a multidose Methotrexate protocol for ectopic pregnancy?

In the context of a multidose Methotrexate protocol for treating ectopic pregnancy, the use of leucovorin is essential for mitigating the side effects of Methotrexate, which is a folate antagonist. Leucovorin, also known as folinic acid, works by providing an alternative source of folate, thus allowing the normal, non-cancerous cells to continue to function and proliferate without being adversely affected by the cytotoxic effects of Methotrexate.

The appropriate leucovorin dose in this protocol is typically calculated based on the patient's weight, with a common dosing strategy being 0.1 mg/kg administered intramuscularly. This dosing allows for effective rescue of normal cells from the toxic effects of Methotrexate, while ensuring that sufficient concentrations are present to achieve the desired therapeutic effect without allowing tumor progression, if applicable.

The rationale behind the specific dosing is to provide a well-balanced approach to patient safety and the effectiveness of the Methotrexate treatment. Hence, using 0.1 mg/kg IM aligns with established protocols for managing ectopic pregnancies effectively while minimizing potential adverse effects associated with Methotrexate therapy.