table of contents
- Can you take antibiotics and birth control together?
- Taking other antibiotics with oral contraceptives
- Other birth control drug interactions
- Some medications must be taken with birth control
- Speak with your healthcare provider
If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
The pill was one of the most important medical advancements of the 20th century. It gave women all around the world the freedom to make choices about their reproductive health. That’s pretty powerful! So, if you’re taking oral contraceptives to prevent pregnancy, you want to make sure it works the way it’s supposed to.
You might know that some medications can have a negative interaction with birth control, making it less effective. Do antibiotics fall into that category?
Antibiotics are usually something we take for a short period of time, and it’s often unpredictable when we’ll need them. After all, you can’t predict when you might get a urinary tract infection (UTI) or other infection that requires antibiotics. If you need to take antibiotics, will your birth control still work?
Let’s take a look.
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Can you take antibiotics and birth control together?
In most cases, yes, you can take antibiotics while you’re on birth control. There haven’t been any strong studies showing that most antibiotics make birth control less effective (Simmons, 2018).
According to the Centers for Disease Control and Prevention (CDC), there are only two types of antibiotics you shouldn’t take with birth control (CDC, 2020):
- Rifampin (brand name Rifadin)
These are part of a class of drugs called rifamycins, most commonly used to treat tuberculosis (and some infections that are resistant to other medications) (Horne, 2011). Tuberculosis is not that common in the U.S., and rates are declining every year, so these medications aren’t used that often (“Trends in tuberculosis,” 2019). That means most women on birth control probably don’t need to worry about this particular interaction.
If you do need to go on a rifamycin while taking the pill, you’ll just need to use a back-up form of birth control (like condoms). This is because rifampin can cause breakthrough bleeding and possibly pregnancy if taken while on the pill (Zhanel, 1999).
How does rifampin interfere with hormonal contraception?
Even though rifampin isn’t so commonly prescribed, you might be curious about how it can interfere with the effectiveness of your birth control. The way this works is that rifampin lowers the concentration of estrogen in your blood plasma. It does this by increasing liver enzymes (these are the enzymes in the liver that play a big role in processing estrogen) (Zhanel, 1999). Since combined oral contraceptives work by preventing ovulation through a combination of the hormones estrogen and progestin, decreasing estrogen hormone levels gets in the way of an important part of the pill’s function (Cooper, 2020).
Taking other antibiotics with oral contraceptives
What about other types of antibiotics? If you get a UTI, your healthcare provider will probably prescribe one of the many other antibiotics, such as trimethoprim-sulfamethoxazole (brand name Bactrim) or nitrofurantoin (brand name Macrobid). Can you take those with hormonal birth control?
You can! The only antibiotics that might interfere with birth control are rifampin and rifabutin. All other antibiotics, including common antibiotics like amoxicillin and ciprofloxacin, should be safe, even if you’re taking contraceptive pills (Simmons, 2018).
Your healthcare provider might still recommend using a back-up form of birth control while you’re on the antibiotics, just to be extra safe. Be sure to follow the medical advice of your healthcare provider.
Other birth control drug interactions
Antibiotics aren’t the only medication interaction you need to be concerned about when taking birth control. Most medications are completely safe with combined oral contraceptives, but there are certain other drugs that can interfere with the pill, making it work less effectively. There are two main types of drugs that can be problematic with the pill:
- Antiretrovirals (drugs used to treat HIV)
- Anticonvulsants (drugs used to treat and prevent seizures)
There’s only one antiretroviral that can interfere with the pill, a drug called fosamprenavir (brand name Lexiva) (Britton, 2020). If you’re on the pill and have HIV, your healthcare provider will likely recommend using a back-up method of birth control. Or, she may prescribe a different HIV medication.
With anticonvulsants, the list of drugs that interact with hormonal contraceptives is much longer. If you have a seizure disorder, you’ll need to work closely with your healthcare provider to find the right combination of drugs for you. The anticonvulsant (also called antiepileptic) drugs that can make birth control less effective are (Reddy, 2010):
- Carbamazepine (brand name Tegretol)
- Felbamate (brand name Felbatol)
- Lamotrigine (brand name Lamictal)
- Oxcarbazepine (brand name Trileptal)
- Phenobarbitone (brand name Luminal)
- Phenytoin (brand name Dilantin)
- Primidone (brand name Mysoline)
- Topiramate (brand name Topamax)
There are many other anticonvulsant drugs that are perfectly fine to take while on the pill. If you need to be on one of the above medications, though, you should use another form of birth control.
Lastly, some herbal medicines, such as St. John’s wort, can interfere with the pill, causing side effects such as breakthrough bleeding. It’s possible these substances can decrease the effectiveness of birth control pills, so back-up birth control is recommended (Murphy, 2005).
Some medications must be taken with birth control
While most medications can be taken safely with birth control, there are some medications that must be taken with some form of reliable birth control since it’s unsafe to get pregnant while taking them. Drugs that fall into that category are teratogenic, which means they can cause malformations in an embryo. Here are some of the most common teratogenic drugs that should be taken with a reliable form of birth control (Tsamantioti, 2020):
- Isotretinoin—This oral acne medication is better known by its brand name, Accutane. It is so dangerous to get pregnant while on isotretinoin that patients are required to sign an agreement to be on two reliable forms of birth control while taking it.
- Antiepileptic drugs—Wait a minute, didn’t we just say in the previous section that many antiepileptic drugs make hormonal contraception less effective? Yes, but many antiepileptic drugs are teratogenic, too. It’s important to follow your healthcare provider’s advice about using another reliable birth control method while taking antiepileptic or anticonvulsant drugs.
- Certain antibiotics—As we’ve discussed, most antibiotics are safe to take with birth control, with the exception of rifampin and rifabutin. There are two types of antibiotics, though, that should be taken with birth control since they are unsafe during pregnancy. Those are tetracycline and fluoroquinolones.
- Warfarin—This is an anticoagulant medication used for several purposes, including in patients with clotting disorders, to treat an active blood clot, and in patients with mechanical heart valves. This drug is unsafe during pregnancy, so if you need to be on it long-term, you’ll need to use a reliable form of contraception at the same time.
- Antithyroid medications—Certain antithyroid medications, namely propylthiouracil, methimazole, and carbimazole, should be taken with birth control.
- Fluconazole—In high doses, this antifungal medication (known by its brand name, Diflucan) can cause birth defects. In low doses, it’s probably safe, but if you need to be on a higher dose, birth control is recommended (Kaplan, 2015).
Speak with your healthcare provider
If you’re taking combined oral contraceptives to prevent pregnancy, the last thing you need is to worry that they may not be working properly and cause an unintended pregnancy. While most medications are safe to take while on the pill, it’s important to discuss any concerns with your healthcare provider if you need to go on any other medications, whether long-term or temporarily. If you’re taking a medication that might decrease the effectiveness of your birth control pills, just use a back-up form of birth control during that time.
- Britton, L. E., Alspaugh, A., Greene, M. Z., & McLemore, M. R. (2020). CE: An Evidence-Based Update on Contraception. The American journal of nursing, 120(2), 22–33. doi: 10.1097/01.NAJ.0000654304.29632.a7. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7533104/
- Centers for Disease Control and Prevention. (2019). Trends in Tuberculosis. Retrieved from https://www.cdc.gov/tb/publications/factsheets/statistics/tbtrends.htm
- Cooper D.B, Mahdy H. (2020). Oral Contraceptive Pills. StatPearls. 2020 Jan. Retrieved from: https://www.ncbi.nlm.nih.gov/books/NBK430882/
- Horne, D. J., Spitters, C., & Narita, M. (2011). Experience with rifabutin replacing rifampin in the treatment of tuberculosis. The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 15(11), 1485–i. doi: 10.5588/ijtld.11.0068. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3290133/
- Kaplan, Y. C., Koren, G., & Bozzo, P. (2015). Fluconazole exposure during pregnancy. Canadian family physician Medecin de famille canadien, 61(8), 685–686. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541431/
- Murphy, P. A., Kern, S. E., Stanczyk, F. Z., & Westhoff, C. L. (2005). Interaction of St. John’s Wort with oral contraceptives: effects on the pharmacokinetics of norethindrone and ethinyl estradiol, ovarian activity and breakthrough bleeding. Contraception, 71(6), 402–408. doi: 10.1016/j.contraception.2004.11.004. Retrieved from https://pubmed.ncbi.nlm.nih.gov/15914127/
- Reddy D. S. (2010). Clinical pharmacokinetic interactions between antiepileptic drugs and hormonal contraceptives. Expert review of clinical pharmacology, 3(2), 183–192. doi: 10.1586/ecp.10.3. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2848501/
- Simmons K. B., Haddad L. B., Nanda K., & Curtis K. M. (2018). Drug interactions between non-rifamycin antibiotics and hormonal contraception: a systematic review. American journal of obstetrics and gynecology, 218(1), 88–97.e14. Doi: 10.1016/j.ajog.2017.07.003. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28694152/
- Tsamantioti E.S., Hashmi M.F. (2020). Teratogenic Medications. StatPearls. 2020 Jan. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK553086/
- Zhanel, G. G., Siemens, S., Slayter, K., & Mandell, L. (1999). Antibiotic and oral contraceptive drug interactions: Is there a need for concern?. The Canadian journal of infectious diseases = Journal canadien des maladies infectieuses, 10(6), 429–433. doi: 10.1155/1999/539376. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3250726/
Most antibiotics do not affect contraception. It's now thought that the only types of antibiotic that interact with hormonal contraception and make it less effective are rifampicin-like antibiotics. These can be used to treat or prevent diseases, including tuberculosis and meningitis.What do you do if you take antibiotics and birth control? ›
Antibiotics like amoxicillin won't change the effectiveness of your birth control. The antibiotic rifampin (also known as Rifadin and Rimactane) is the only exception — it can lower the effectiveness of the pill, patch, and ring.How long after taking antibiotics does birth control work? ›
If you will be taking antibiotics LONG-TERM, such as for acne, you should use the second method of birth control for at least two weeks after starting the antibiotic.Why do antibiotics make birth control not work? ›
Antibiotics are suspected to diminish oral contraceptive efficacy by two main mechanisms: induction of the cytochrome P450 group of hepatic microsomal enzymes and interference with enterohepatic cycling of ethinylestradiol (6) (Table 1).What medication cancels out birth control? ›
- Carbamazepine (Carbatrol, Epitol, Equetro, Tegretol)
- Felbamate (Felbatol)
- Oxcarbazepine (Trileptal)
- Phenobarbital (Luminal)
- Phenytoin (Dilantin, Phenytek)
- Primidone (Mysoline)
- Topiramate (Topamax)
The main thing that makes the pill not work is not taking it every day. But other things, like vomiting or having diarrhea for more than 48 hours (2 days) may lower how well the pill prevents pregnancy. If you take any of these while you're on the pill, use condoms as a backup method.What can you not do while on birth control? ›
- You don't take the pill on schedule.
- You're taking medication that can affect your birth control.
- Your vaginal ring falls out.
- You don't check your diaphragm before you use it.
- You use expired or damaged condoms.
- You use an oil-based lubricant with a condom.
Will antibiotics continue to work after you stop taking them? Yes, antibiotics continue their antibacterial effects after your last dose. Some will last in the body longer than others.How long are you protected after taking antibiotics? ›
You're usually no longer infectious 24 hours after starting a course of antibiotics, but this time period can sometimes vary.What should you not do while taking antibiotics? ›
- Don't: Drink Alcohol. ...
- Do: Take your prescription at the same time every day. ...
- Don't: Take antibiotics with milk or fruit juice. ...
- Do: Protect yourself from the sun. ...
- Don't: Hesitate to talk to your doctor about your concerns.
Can I get pregnant if I take antibiotics? In most cases, no, as long as you continue to use your hormonal contraception as prescribed you are safe from pregnancy even if you are on antibiotics. It is a myth that all antibiotics will interfere with the efficacy of your birth control pill.Does birth control work right away? ›
If you start taking the combination pill on the first day of your period, you'll be protected against pregnancy right away. However, if you don't begin your pill pack until after your period has started, you'll need to wait seven days before having unprotected sex.Can an infection come back after antibiotics? ›
Once the antibiotic treatment ends, the few remaining bacteria can grow again, restoring the infection. Infections that can't be treated are a significant problem.How long does it take for the birth control pill to be absorbed into your system? ›
Combination pills contain two hormones — estrogen and progestin — that prevent ovulation. If a person takes the first dose within 5 days of their period starting, it is effective immediately. If they start at any other time, the pill takes 7 days to work.