Skip to content

Drug interactions

Methotrexate + Ticarcillin

Severity: Major

Methotrexate and Ticarcillin: major interaction.

Last updated Sources: US FDA label

For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.

Summary

Penicillins can raise methotrexate serum levels, leading to myelosuppression and gastrointestinal toxicity. The effect is most important with high-dose methotrexate or renal impairment.

What this interaction means in plain words

Methotrexate and Ticarcillin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.

Evidence level: Moderate

Why it happens

Competition for renal tubular secretion reduces methotrexate renal clearance.

What to do

Monitor methotrexate levels where available, with blood counts and renal function. Choose an alternative antibiotic when methotrexate doses are high.

What to ask your pharmacist

  • Does the benefit of taking both outweigh the risk in my case?
  • Do I need any blood test, ECG or other check while on both?
  • What early warning signs should I watch for, and what should I do if they appear?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

Pro+ members

Unlock the full page

Create an account and start a Pro+ trial to unlock the full management advice for Methotrexate and Ticarcillin, the additional notes, the evidence detail and the whole-prescription interaction checker.

  • Full clinical management advice
  • Additional notes
  • Evidence detail
  • Interaction checker for a whole prescription

Try Pro+ free for 7 days on the web. No card needed.

References

Frequently asked questions

Can I take Methotrexate with Ticarcillin?

MediHelp rates the interaction as major. Methotrexate and Ticarcillin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Penicillins can raise methotrexate serum levels, leading to myelosuppression and gastrointestinal toxicity. The effect is most important with high-dose methotrexate or renal impairment.

How serious is the interaction between Methotrexate and Ticarcillin?

MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor methotrexate levels where available, with blood counts and renal function. Choose an alternative antibiotic when methotrexate doses are high.

What other medicines interact with Methotrexate?

MediHelp also lists interactions of Methotrexate with, for example, Acitretin, Adenovirus types 4 and 7 live, Influenza virus vaccine quadrivalent intranasal. The full list is on the Methotrexate page.

Full monographs, dosing and an interaction checker in the MediHelp app

Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.

Browse A–Z · Drug interactions

Get the app Sign in