Severe Adverse Toxic Effects of Low-Dose Methotrexate Treatment on an Ectopic Pregnancy Patient With Methylenetetrahydrofolate Reductase Mutations: A Case Report

Safety profile of methotrexate used off-label in ectopic pregnancy: an active monitoring study based on a Chinese hospital pharmacovigilance system

OBJECTIVE

Methotrexate (MTX) is characterized as first-line therapy although its indication of ectopic pregnancy is off-label use. We aimed to conduct a retrospective cohort study to investigate the incidence, characteristics of adverse drug reactions (ADRs) of MTX, provide valuable insights for medical workers.

METHODS

Basing on China Hospital Pharmacovigilance System (CHPS), a retrospective analysis was performed to evaluate the safety of MTX (n = 672). An active monitoring model was set to detect ADR signals from the hospital information system. Frequency, Common Terminology Criteria for Adverse Events (CTCAE) grade proportion and association of dose exposure with ADRs were presented as outcomes.

RESULTS

The total incidence of ADRs was 54.0%. Anaemia (37.6%) was the most frequent ADR, followed by hepatic function abnormal (11.3%), hyperuricemia (6.1%), neutropenia (4.6%), leukopenia (4.0%), and dyslipidaemia (2.5%). For the composition of all ADRs, CTCAE grade one, two and three dominated for 86.3%, 12.1% and 1.6%, respectively. The severity of hepatic function abnormal was more serious in the two-dose exposed group (p = .021), while other types of ADRs had no statistical or clinical differences. Logistic regression analysis showed the incidence of any ADRs (OR 1.87 [1.31-2.64]; p = .001), hepatic function abnormal (OR 2.75 [1.69-4.48]; p < .001), dyslipidaemia (OR 5.15 [1.87-14.13]; p = .001) were significantly higher in the two-dose exposed group. After adjusted, the positive associations were still maintained.

CONCLUSIONS

MTX is quite safe in ectopic pregnancy, despite its mild to moderate hematotoxicity, hepatotoxicity and nephrotoxicity. Taking CHPS can present the accurate denominator of the incidence of adverse drug reactions into account, our study advocates that it may have great potential to be used as an active monitoring tool for off-label drug use risk management.

Low-dose methotrexate-induced renal failure in a patient with ectopic pregnancy: a case report

BACKGROUND

Methotrexate is an anticancer drug from the antimetabolite class. It is also used in gynecology and obstetrics for the medical treatment of ectopic pregnancies. Low-dose methotrexate-induced adverse toxic effects are rare. We report a case of toxic effect associated with severe renal insufficiency induced by LD-MTX (Low-Dose Methotrexate) for ectopic pregnancy.

CASE PRESENTATION

A 46-year-old Chinese woman was in an operation for an ectopic pregnancy of tubal interstitial pregnancy. The embryo villus was so little that we were not sure if it was evacuated, then it was followed with 50 mg methotrexate injection of intramuscular adjacent the uterine horn in the operation. 48 hour later after injection the patient presented with renal failure. The personalized genetic testing showed that MTHFR (677C > T) and ABCB1 (3435T > C) were detected. Gradually, the symptoms improved after calcium leucovorin (CF) rescue, continuous renal replacement therapy (CRRT), promoting blood system regeneration, and multiple supportive treatments.

CONCLUSIONS

When toxic effects are suspected, detecting the polymorphisms of an MTHFR gene and monitoring MTX concentration in blood could assist us to formulate individualized and active treatments. The management should be multidisciplinary and as much as possible within an intensive care unit.