Comparison of interactions between warfarin and cephalosporins with and without the N-methyl-thio-tetrazole side chain

Right femoral vein and right dorsal artery thrombosis in childhood acute myeloid leukemia: A case report

BACKGROUND

It is rare for newly diagnosed (de novo) or newly treated acute myeloid leukemia (AML) complicated with thrombotic complications, especially combined arterial and venous thrombosis.

METHODS

We reported a 13-year-old boy diagnosed with AML and leukocytosis, who developed right femoral vein and right dorsal artery thrombosis during chemotherapy. After treatment with low molecular weight heparin, diosmin, and alprostadil, symptoms were relieved. Unfortunately, the child suffered from coagulopathy afterward, which was unexpectedly caused by vitamin K deficiency.

RESULTS

After supplementation with vitamin K and prothrombin complex concentrate, coagulation function recovered.

CONCLUSION

For childhood AML patients with high thrombotic risks, close monitoring during anticoagulant treatment was necessary. Concomitantly, we should be alert to past medication history and combined medication use, especially those that may lead to vitamin K deficiency, secondary bleeding, and coagulation disorders. Rational use of antibiotics, anticoagulants, and antitumor drugs must be guaranteed.

A super-geriatric patient with gastrostomy underwent life-threatening prothrombin time-international normalized ratio prolongation by warfarin following fasting and antibiotic therapy

Key Clinical Message

A 97-year-old woman with gastrostomy had a drastic enhancement for PT-INR after starting antibiotic therapy. Possible causes include (1) vitamin K deficiency due to fasting and (2) a combination of warfarin and antibiotics.

Abstract

Geriatric and Asian-descent patients are more sensitive to the effects of warfarin, a key anticoagulant drug. In this report, we present a 97-year-old bedridden woman being treated with warfarin for cardiogenic cerebral infarction and femoral neck replacement as part of in-home medical care with a gastrostomy and was admitted to our hospital after developing pneumonia. We discontinued warfarin and started antibiotics, and her pneumonia-related symptoms improved. Eleven days after restarting warfarin, the patient's PT-INR surpassed the upper limit for measurement (over 10). We considered the mechanism might be triggered by (1) fasting, low nutrition status; and (2) antibiotics secondary to risk factors such as gastrostomy and being a super-geriatric woman. We recommend careful monitoring of PT-INR in patients treated with warfarin and antibiotics, especially in the setting of gastrostomy or older persons.

Effects of piperacillin/tazobactam or cefepime on folinate dose in patients receiving high-dose methotrexate: A retrospective cohort study using Japanese administrative claims data

INTRODUCTION

Delayed methotrexate (MTX) clearance with the co-administration of piperacillin/tazobactam (PIPC/TAZ) has been reported. Penicillins have been associated with reduced MTX clearance but the evidence is limited. There are no cases described with cefepime but penicillins are listed as interacting with MTX. We aimed to reveal whether the co-administration of PIPC/TAZ or CFPM affects MTX clearance using data from an administrative database.

METHODS

We used data from the JMDC database, a large insurance claims database constructed in Japan. We included patients who were prescribed PIPC/TAZ or CFPM between days 1 and 3 in high-dose MTX (HD-MTX). We compared one co-administration episode (with PIPC/TAZ or CFPM) to one control episode (without), as a match-control study of two different episodes in the same patient. The primary outcomes were the duration and cumulative dose of leucovorin (LV) as a surrogate indicator of delayed MTX clearance.

RESULTS

Three patients who were co-administered PIPC/TAZ and 16 patients who were co-administered CFPM with HD-MTX were included. In the PIPC/TAZ group, the duration and the cumulative doses of LV were similar in co-administration and control episode (median 3.0 vs. 3.0 days and 288.0 vs. 219.0 mg). In the CFPM group, the duration and the cumulative doses of LV were not significantly different in co-administration and control episode (3.0 vs. 4.0 days and 169.5 vs. 258.0 mg).

CONCLUSIONS

Our findings revealed that PIPC/TAZ did not necessarily cause a delay in MTX clearance during HD-MTX therapy. Moreover, the co-administration of CFPM with HD-MTX did not affect MTX clearance.