Provided by our Ask the MS Nurse: Cherie C. Binns RN BS MSCN
By:
Ellen Whipple Guthrie, Pharm.D.
Oral
contraceptives – birth control pills – are considered one of the safest and
most effective means of preventing pregnancy. However, oral contraceptives are
not for all women. If you are over the age of 35 and smoke cigarettes, the pill
increases your risk for medical problems, including heart attacks, blood clots,
and stroke. In fact, a study recently published in the Lancet found that women
who smoke are 25% more likely to die from any cause if they also take oral
contraceptives.
Because oral
contraceptives are metabolized in the liver, they can interact with many
medications, including some of the more common ones prescribed to women with
MS. Let’s take a look at some of those medications, along with what you can do
to protect yourself.
Different
Drugs, Different Interactions
Various types
of drug interactions can occur between oral contraceptives and prescription,
over-the-counter, and herbal products.
- Some
medications can reduce the effectiveness of oral contraceptives (see table
1). Clearly, women taking both oral contraceptives and any of these
medications should talk with both their MS specialist and gynecologist. It
is generally a good idea to use a second method of birth control as a
backup. Barrier methods (including condoms, diaphragms, and new-generation
intrauterine devices) are considered good options. - Oral
contraceptives may decrease the effectiveness of some medications (see
table 2). An increased dose of the medication may be needed in order to
obtain maximum benefits. - Oral
contraceptives can increase the effectiveness of some medications (see
table 3). In many cases, a decreased dose of the medication is needed in
order to avoid too much active drug.
What
About the Disease-Modifying Drugs?
There is no
evidence indicating that oral contraceptives interfere with any of the
commercially available disease-modifying drugs – Avonex®, Betaseron®,
Copaxone®, Novantrone®, Tysabri®, or Rebif®. However, it is recommended for
women in their childbearing years to use some form of birth-control while
taking these drugs, since they have not been extensively studied in pregnancy.
Table
1:
Medications that can reduce the effectiveness of oral contraceptives:
- All
antibiotics - Anti-seizure
medications, including carbamazepine (Tegretol®), phenytoin (Dilantin®),
phenobarbital, and primidone (Mysoline®) - Modafinil
(Provigil®) - St.
John’s Wort
Table
2:
Oral contraceptives may decrease the effectiveness of these medications:
- Salicylates
(over-the-counter or prescription pain and fever reducers) - Benzodiazepines—such
as lorazepam (Ativan®), oxazepam (Serax®), and temazepam (Restoril®)
Table
3:
Oral contraceptives may increase the effectiveness of these medications:
- Benzodiazepines—such
as diazepam (Valium®) - Beta
blockers—including propranolol (Inderal®) - Corticosteroids—including
prednisone or methylprednisolone - Tricyclic
antidepressants—including amitriptyline (Elavil®)
If you have any
questions about the interactions between any of your medications, always talk
to your doctor and/or pharmacist.
(Last reviewed
7/2009)
WATCH OUR MS EDUCATIONAL VIDEOS by Topic, found here: www.youtube.com/msviewsandnews
JOIN our Facebook Page: www.facebook.com/msviewsandnews
————-
Thank you
Stu’s Views & MS News, is a publication of:
