02 Nov Ask the Pharmacist: Topiramate May Create Risk of Contraceptive Failure
Questions answered by:
Rich Wenzel, Pharm.D.
Diamond Headache Clinic Inpatient Unit
St. Joseph’s Hospital, Chicago, IL
Q. My migraine attacks are becoming more frequent, so my doctor prescribed topiramate (Topamax®). I have taken birth control pills for many years and I just read that topiramate may cause a negative interaction. Is this true?
A. The Food and Drug Administration recently approved topiramate for the prevention of migraine headaches. The recommended dose for migraine is 100 mg per day. Topiramate was originally developed approximately a decade ago for the treatment of seizures, at much higher dosages, ranging from 400 mg to 1600 mg per day.
One disadvantage of topiramate is that it can cause your body to metabolize, or break down, certain drugs more rapidly than normal, reducing the efficacy of these medications. One such medication is estrogen, the key ingredient of estrogen-based birth control pills. In studies involving seizure patients taking the usual, higher topiramate doses, a small percentage did experience contraceptive failure, resulting in an unintended pregnancy.
An important question that still remains unanswered is whether the lower topiramate dose typically prescribed for migraine patients also creates a contraceptive failure risk. Until this question is answered, the prudent patient should make use of additional or alternative contraceptive measures. One option is to use non-estrogen-containing birth control pills, such as those containing progesterone only; i.e., the “mini-pill”. There are other options and I encourage you to speak with your family physician or OB/GYN.
Migranal® Now in Easier-to-Use Form
Q. Migranal has worked well for me over the years. Recently, I refilled my prescription and was given a different bottle. My pharmacist said the old Migranal bottle was discontinued. Is this true? Will this new bottle last longer?
A. Earlier this year Valeant, the manufacturer of Migranal (dihydroergotamine nasal spray) introduced an easier-to-use apparatus. Thus, your pharmacist is correct in that your familiar Migranal bottle has been permanently replaced.
Unlike the old pump device, which had a glass vial that had to be broken prior to use, the new pump device is attached with a simple screw top, eliminating the need to break glass. The remaining assembly steps are similar to the old Migranal: after opening the vial and inserting the pump device, prime the pump four times, then spray once into each nostril. Wait 15 minutes, then again spray once into each nostril. In some instances, your healthcare provider may prescribe an additional spray into each nostril two hours later, for a total of six sprays.
You should dispose of the entire device after either reaching the maximum prescribed dose or eight hours after assembly, whichever comes first. Should we indicate why this is important. I’ll ask Rich why.
Avoiding Drugs that Induce Drowsiness
Q. I work as a police officer and department regulations prohibit me from taking medications that might make me drowsy while on duty. Otherwise I will be limited to only deskwork, something I wish to avoid. Too many doctors simply give me narcotics for my migraines. What are some non-drowsy drug options?
A. Your situation clearly illuminates the medication-related issues patients have to address in the “real world.” The National Headache Foundation maintains a state list of physician members, which you can obtain for free by calling the NHF at 1-888-NHF-5552. I would encourage you to find a healthcare provider in your area familiar with headaches and work with him or her to design a treatment plan tailored to your needs. Undoubtedly this provider will know that narcotics are generally poor choices for migraine, especially as first-line treatment. In some situations they may be appropriate as “rescue” drugs, although not for you given your work requirements.
You and your healthcare provider can select from several types of medications that are unlikely to make you drowsy, including nonsteroidal anti-inflammatory drugs (NSAIDs) or triptans. There are multiple drugs and formulations (e.g., pill, nasal spray, injection) within each of these classes. Dihydroergotamine (discussed above) is also an option for you.