Topotecan/P-glycoprotein (P-gp) Inhibitors Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Your medicine may cause your body to absorb more topotecan than expected.

What might happen:

The levels of topotecan in your blood may increase and cause more side effects than expected. You should watch for increased signs of increased bruising, feeling tired, and diarrhea.

What you should do about this interaction:

Let your healthcare professional (e.g. doctor or pharmacist) know that you are taking these medicines together. Let your doctor know if you experience increased bruising, tiredness, or diarrhea. Your doctor may want to decrease the dose of your topotecan or change your other medicine.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.

  • 1.Hycamtin Oral (topotecan) US prescribing information. GlaxoSmithKline October, 2011.
  • 2.US Food and Drug Administration (FDA). Drug Development and Drug Interactions: Table of Substrates, Inhibitors and Inducers. Available at: http://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources/D rugInteractionsLabeling/ucm093664.htm. Updated 08/05/2011.