Irinotecan/Selected Anticonvulsants
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:
Phenytoin, phenobarbital, and carbamazepine may speed up how quickly your liver processes irinotecan.
What might happen:
The amount of irinotecan and the active metabolites in your blood may decrease and it may not work as well.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Your doctor may want to check the amounts of irinotecan in your blood and may want to adjust the dose of your medicine while you are taking phenytoin, phenobarbital, or carbamazepine or your doctor may want to change your anticonvulsant 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.
References:
1.Camptosar (irinotecan hydrochloride) US prescribing information. Pharmacia & Upjohn Company May, 2010.
2.Kuhn JG. Influence of anticonvulsants on the metabolism and elimination of irinotecan. A North American Brain Tumor Consortium preliminary report. Oncology (Huntingt) 2002 Aug;16(8 Suppl 7):33-40.
3.Mathijssen RH, Sparreboom A, Dumez H, van Oosterom AT, de Bruijn EA. Altered irinotecan metabolism in a patient receiving phenytoin. Anticancer Drugs 2002 Feb;13(2):139-40.
4.Murry DJ, Cherrick I, Salama V, Berg S, Bernstein M, Kuttesch N, Blaney SM. Influence of phenytoin on the disposition of irinotecan: a case report. J Pediatr Hematol Oncol 2002 Feb;24(2):130-3.
5.Gajjar A, Radomski K, Bowers D, Chintagumpala M, Thompson S, Houghton P, Stewart C. Pharmacokinetics of Irinotecan (IRN) and metabolites in pediatric high-grade giloma patients with and without co-administration of enzyme-inducing anticonvulsants. 2000.
6.Reid J, Buckner L, Schaaf L, Cha S, Wright K, Marks R, Wiesenfeld M, Pfeifle D, Harfield A, Krook J, Duncan B, Miller L. Anticonvulsants alter the pharmacokinetics of Irinotecan (CPT-11) in patients with recurrent glioma. 2000.
