Details of Drug-Drug Interaction
| Drug General Information (ID: DDIJMD5S1Y) | |||||||||
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| Drug Name | Methotrexate | Drug Info | Benzylpenicillin (potassium) | Drug Info | |||||
| Drug Type | Small molecule | Small molecule | |||||||
| Therapeutic Class | Antimetabolites | Antibiotics | |||||||
| Structure | |||||||||
| Mechanism of Methotrexate-Benzylpenicillin (potassium) Interaction (Severity Level: Major) | |||||||||
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| Competitive inhibition of renal tubular secretion Click to Show/Hide Mechanism Graph | |||||||||
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| Drug Name | Methotrexate | Benzylpenicillin (potassium) | |||||||
| Mechanism | Methotrexate | Competitive inhibition of renal tubular secretion of methotrexate | |||||||
| Key Mechanism Factor 1 | |||||||||
| Factor Name | Renal tubular secretion | ||||||||
| Factor Description | Renal tubular secretion allows selective transfer of substances from the blood around the capillaries into the renal tubules via filtrate. Drug excretion may be reduced when two drugs compete for renal tubular secretion. | ||||||||
| Mechanism Description |
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| Recommended Action | |||||||||
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| Management | If a penicillin must be used concurrently, close monitoring of methotrexate serum concentrations and of the patient for evidence of serious methotrexate toxicity are recommended. Leucovorin rescue should be available. Methotrexate dose reductions may be necessary. If broad-spectrum antibiotic coverage is needed during high-dose methotrexate therapy, use of other antimicrobials may be preferable. Patients should be advised to promptly report symptoms including fever, chills, sore throat, bruising, bleeding, stomatitis, or malaise to their physician. | ||||||||