Related Experiment Video
Updated: Dec 10, 2025

Cytotoxic Efficacy of Photodynamic Therapy in Osteosarcoma Cells In Vitro
Published on: March 18, 2014
Significant interaction between high-dose methotrexate and high-dose piperacillin-tazobactam causing reversible
Irene Krämer1, Jelena Rosentreter1, Marius Fried2
1Department of Pharmacy, University Medical Center, Johannes Gutenberg University Mainz, Mainz, Germany.
Introduction:
Pharmacokinetic interaction of high-dose methotrexate (MTX) and other concomitantly administered renally secreted medicinal products may lead to insufficient methotrexate serum level decrease and significant MTX toxicity.
Case Report:
We report the case of an 18-year-old male patient treated with high-dose MTX for an osteosarcoma and with high-dose piperacillin-tazobactam at the same time. MTX serum levels were severely elevated 24 hours after the MTX infusion and did not decrease in accordance with the specific calcium folinate rescue protocol. The patient experienced renal failure accompanied by neurological symptoms, most consistent with MTX-related renal and CNS toxicity.Management and outcome: After discontinuation of piperacillin-tazobactam, intensified calcium folinate rescue therapy, and IV hydration, the MTX serum levels decreased appropriately, and toxicity symptoms resolved.
Discussion:
Severe MTX-related toxicity, caused by drug-drug interaction, suggests that the concomitant use of high-dose MTX and high-dose piperacillin-tazobactam should be avoided generally.
More Related Videos
Related Concept Videos
Combined Effects of Drugs: Synergism
Such synergistic combinations...
Drug Accumulation During Multiple Dosing: Intermittent IV Infusions
Therapeutic Drug Monitoring: Affecting Factors
Renal Failure: Dose Adjustments
Reduced renal clearance and elimination rate are common outcomes of renal impairment. These alterations lead to a prolonged elimination half-life and an altered apparent volume of distribution for drugs. As a result, dosage adjustments are typically necessary to maintain optimal drug levels in the body.
However, dosage adjustments...
Pharmacokinetics: Drug–Drug Interactions
Desensitization and Tachyphylaxis

