Hormonal Contraceptives/Carbamazepine; Rufinamide
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:
When these two medicines are taken together, your body may process your birth control medicine more quickly.
What might happen:
The effects of your birth control medicine may decrease and cause breakthrough bleeding, spotting, or pregnancy.
What you should do about this interaction:
Talk to your healthcare professional (e.g. doctor or pharmacist) as soon as possible about using a different form of birth control. Contact your doctor if you experience breakthrough bleeding, spotting, or pregnancy.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.Rapport DJ, Calabrese JR. Interactions between carbamazepine and birth control pills. Psychosomatics 1989 Fall;30(4):462-4.
2.Crawford P, Chadwick DJ, Martin C, Tjia J, Back DJ, Orme M. The interaction of phenytoin and carbamazepine with combined oral contraceptive steroids. Br J Clin Pharmacol 1990 Dec;30(6):892-6.
3.Nor-Q-D (norethindrone) US prescribing information. WatsonPharma March, 2005.
4.Doose DR, Wang SS, Padmanabhan M, Schwabe S, Jacobs D, Bialer M. Effect of topiramate or carbamazepine on the pharmacokinetics of an oral contraceptive containing norethindrone and ethinyl estradiol in healthy obese and nonobese female subjects. Epilepsia 2003 Apr;44(4):540-9.
5.Inovelon (rufinamide) UK summary of product characteristics. Eisai Limited January 16, 2007.
6.Banzel (rufinamide) US prescribing information. Eisai Inc. November, 2008.
