Tips for Contraceptive Success: Medications and Inhibitors that Lower Hormonal Contraception Effectiveness

By Dawn Stacey, M. Ed., LMHC, About.com Contraception Guide
(Reprinted with her permission)

Certain medications, antibiotics, and supplements can increase the chances of oral contraceptive (birth control pill), NuvaRing and Ortho Evra patch failure. These drugs and medications can cause interactions when used with some hormonal contraceptives.

If you have any questions about birth control methods, please contact your healthcare provider. You will lower your chances for birth control failure if you have a proper and thorough understanding of how to use your contraceptive.

1. Antibiotics

Some antibiotics used to treat infections may cause the Pill to be less effective.

The following antibiotics/antibacterial agents may interfere with pill use:

•Rifampin: used to treat tuberculosis or meningitis
•Rifabutin: used to treat mycobacterium avium complex
•Tetracycline
•Rifapentine: used to treat TB
•Some penicillin derivatives or cephalosporin (Keflin) may also decrease pill efficiency.

It is impossible to determine if taking an antibiotic will interfere with pill use (since each person's body responds differently), so it is wise to use a back-up method while on antibiotic medication as a precaution and ask your doctor.


2. Anti-HIV Protease Inhibitors

Ritonavir is an antiviral drug that is used to treat human immunodeficiency virus (HIV) infection. If you are using this or another medication for the treatment of the HIV virus or AIDS, ask your healthcare provider if your specific medication will decrease the effectiveness of the pill.


3. Anti-Seizure Medications

Barbiturate medicines for producing sleep or treating seizures (convulsions) could interfere with the effectiveness of the Pill. Examples of these types of medications would be:

•Phenobarbital
•Primidone

The following medications can also help with seizure (convulsion) control in certain types of epilepsy and also treat nerve-related pain. Additionally, Topiramate may also be prescribed to help prevent migraine headaches. These mediactions, as well, may lower pill, nuvaring, or the patch's effectiveness:

•Oxcarbazepine
•Carbamazepine
•Phenytoin
•Topiramate

Please inquire with your healthcare provider if you are taking any of these medications.


4. Antidepressants

Certain medicines prescribed for mental depression, such as Nefazodone, can alter hormone levels. Inquire about these types of medications with your healthcare provider if you are currently being treated with a specific antidepressant.


5. Anti-Fungal Medication

Anti-Fungal Medications, especilally the ones that are typically taken orally for yeast infections can lower the effectivenes of the pill. Additionally, Griseofulvin, an anti-fungal used to treat fungus infections of the skin, hair, and nails may interfere with oral contraceptives or other hormonal birth control.

If you are using one of these types of medications, ask your healthcare provider if your specific medication will decrease the effectiveness of the pill, ring, or patch.


6. Diabetes Medication

Some of the medications for diabetes, including Troglitazone and Pioglitazone can interact with birth control pills. Make sure to discuss these types of medications with your healthcare provider to see if they will affect the use of your oral contraceptives.


7. Anxiety Treatments

Ask your healthcare provider if your specific anti-anxiety medication will decrease the effectiveness of the Pill as certain medicines used to treat anxiety or sleeping problems, such as Diazepam or Temazepam, may interfere with successful combination contraceptive use.


8. Natural Supplements

In addition to prescription medications, certain supplements have been shown to lower the effectiveness of hormonal contraception. These include:

•Soy Isoflavones - natural substances obtained from the soybean plant which claim to reduce the intensity of menopause-related hot flashes and to help maintain strong bones
•St. John's Wort - an herb or dietary supplement that is being promoted for its ability to improve mildly depressed moods


9. Vomiting and Diarrhea

Although not a medication, vomiting and diarrhea may also lower the effectiveness of the pill.

Additionally, the medication, Aprepitant, which is used to prevent or treat nausea and vomiting vcan also interfer with the oral contraceptive effectiveness. If you are experiencing these symptoms or taking this medication, use an additional method of birth control and contact your healthcare provider for advice.


For the rest of Dawn's reprints:

• Tips for Contraceptive Success (introduction to the series)
• What Leads to Contraceptive Failure?
• How To Prevent Condom Failure
• How To Respond to Men's Excuses for Not Wanting to Wear a Condom
• How To Prevent Diaphragm Failure
• How To Decrease Failure with the Fertility Awareness Method
• How To Prevent Oral Contraceptive Failure
• Medications and Inhibitors that Lower Hormonal Contraception Effectiveness
• How to Prevent IUD Failure
  

To learn more about contraception, please visit Dawn's work on About.com.

Or you can consult the Nonviolent Choice Directory's extensive Pregnancy Prevention resources. The Nonviolent Choice Directory also sells nonprescription family planning and safer sex items through our website.