Although the degrees to which antibiotics may affect hormonal birth control vary, there are certain antibiotics which doctors say can cause decreased effectiveness. Antibiotics that are listed as interfering include:
- Rifampin
- Penicillin
- Amoxicillin
- Sulfonamide
- Ampicillin
- Cotrimoxazole
- Tetracycline
- Griseofulvin
- Minocycline
- Metronidazole
- Nitrofurantoin
If you are taking any of these antibiotics while using birth control pills your doctor should recommend that you use a back-up method of birth control (ie. condom). Despite the fact there is little evidence supporting a massive increase in pregnancies with antibiotic use, it is better to be safe than sorry. Use the back-up method during the run of your antibiotic and continue for one week afterwards.
Speak with your doctor if you have any concerns or questions about antibiotics and the effectiveness of your birth control.
BirthControlBuzz is a service company that provides birth control prices, birth control types (prescription required), health administrative services, and birth control statistics predominantly to US patients seeking to purchase birth control on-line.
For more information on types of birth control call 1-866-868-8850 or visit http://www.birthcontrolbuzz.com/.
Birth Control Buzz is a service company that provides birth control prices, types of birth control(prescription required), health administrative services, and birth control statistics predominantly to US patients seeking to purchase pharmaceuticals on-line. For more information, call 1-866-868-8850 or visit http://www.birthcontrolbuzz.com/.
Hi. I am taking a medium dose of birth control and I am also taking an anti-depressant. I went to see a gyn. initially when I was put on the pill. The reason was for irregular mentrual cycles, and I did not say that I was planning on being sexually active in the near future (the doctor did not raise to dosage of the pill to be effective with the presence of the anti-depressant). However, if I were to become sexually active, and I used the pill (at the medium dosage, not raised) and a condom, how safe am I? Would pulling out in addition to those two methods help?Also, how long does it take for the pill to take effect from the first day you start taking it? Thanks a lot!
Comment by Anonymous — August 26, 2007 @ 7:18 am
Just want to double check…does Cipro interfere with Alesse?
Comment by Anonymous — January 7, 2008 @ 1:45 pm
Some antibiotics have been studied and shown not to affect the metabolism of OCPs. Ciprofloxcin (Cipro ®) is one that does not seem to alter metabolism (6). *** source: http://www.wdxcyber.com/ncontr10.htm ***If you are at all uneasy about taking Cipro at the same time as your birth control pills you can always use a condom and spermicide for extra protection.:)
Comment by Ashlynn — January 8, 2008 @ 3:32 pm
how about the effect of zithromax on birth control the nuva ring to be exact
Comment by jessesgirl3610 — January 17, 2008 @ 5:57 pm
i just wondering does solpadol caplets affect birth control ie the pill?
Comment by Anonymous — April 12, 2009 @ 6:36 pm
Dear Anonymous,Solpadol is a preparation that has acetaminophen (paracetomol) and codeine (narcotic – aka Tylenol#3). There should be no problem taking it with birth control pills.
Comment by Janine — April 14, 2009 @ 1:29 pm
is medaclav a combination of amoxillin and clavulanic acid safe during taking loette or should i stop the BCP for the course of the antibioitcs''''.
Comment by Anonymous — August 4, 2009 @ 6:48 am
Dear Anonymous,If you are taking antibiotics, use back up contraception during the period you are taking antibiotics.
Comment by Janine — August 4, 2009 @ 1:35 pm
helo i have recently started takig the contraceptive yasmin.I am on my second month of the pill. i usually start my period of friday. I was due to start my period last friday, but i havent started yet? i have had a my period while being on this pill brefore, but haven't got it again for the second time. Should i be worried?
Comment by carmel — October 1, 2009 @ 3:41 am
Dear Carmel,Are you taking any antibiotics? If you are you should be using back-up contraception such as condoms or spermicide because certain antibiotics reduces the effectiveness of birth control and if you did not use back up contraception while on antibiotics, there is a chance that you may be pregnant. Ask your doctor if the antibiotic you are taking affects the effectiveness of birth control and get a pregnancy test.If you are not taking any antibiotics, and this is your first time on contraceptive pills, it sounds like your body is just trying to get used to the pill and that your period may be missed on the first month. If you are worried, talk to your doctor.Goodluck
Comment by Janine — October 1, 2009 @ 10:35 am
ok so my problem is that i'm taking ciprofloxacin (500mg for 5 days). im also taking bc pills. i completely forgot that i should use a condom in addition to the pill while on antibiotics. however,i see that u dont have ciprofloxacin listed as one of the antibiotics that decrease the pills effectiveness.. should i be worried? Help please "/
Comment by Anonymous — November 13, 2009 @ 10:41 pm
Dear Anonymous,Ciprofloxacin does not change the effectiveness of birth control pills. You should be fine.
Comment by Janine — November 16, 2009 @ 9:39 am
There is obviously a lot to know about this. I think you made some good points in Features also.
Comment by Anonymous — December 29, 2009 @ 5:32 pm
I am on the nuvaring and also get reoccuring UTIs. My doc gave me Nitrofur pills to take after intercourse. I took one dose after sex and then had sex again a few days later. With just one pill taken, how worried should I be? I feel stupid now, but at the time (and with my boyfriend on leave from the Navy) I didn't think about a backup method.
Comment by Anonymous — January 6, 2010 @ 10:23 am
Dear Anonymous,If you are worried that you may be pregnant, chances of Nitrofur pills interacting with the nuvaring is very small. Nitrofur is an antibiotic that does not lessen the effectiveness of birth control pills and the ring. You are most likely not pregnant, but if you are worried, take a pregnancy test.To prevent UTI's, it is recommended that both partners should take a shower before having sex to decrease the chance of bacteria from entering into the urinary tract during intercourse.goodluck:)
Comment by Janine — January 7, 2010 @ 3:49 pm
Hello,I have a medical problem involving recurring urinary tract infections. Because of this, I am take Cipro 500mg daily for the next 6 months. I am on prophylactic treatment. Since this is long-term, will it decrease the effectiveness of my birth control pill, Trinessa? Thank you for your help!
Comment by Anonymous — April 11, 2010 @ 8:54 am
Dear Anonymous,It is recommended to ask your doctor or pharmacist if the antibiotic that your doctor prescribed to you will affect your birth control pills. Just in case, whenever you go on antibiotics, always use back up contraceptive (ie. condoms or spermicide).
Comment by Janine — April 12, 2010 @ 4:11 pm
Hi there, I am taking Cephalexin 250mg for a week for a small infection in my toe and I am also on the pill. Will this affect the pill? Thanks.
Comment by Anon — June 19, 2010 @ 1:56 am
Dear Anon,
It may affect the pill, just in case you should use back up contraceptives until you finish the Cephalexin.
Janine
Comment by Janine — June 25, 2010 @ 10:53 pm
I am on nuvaring and get urinary tract infections all the time. My doctor resently wrote a prescription for cipro for me. Will it affect the nuvaring’s effectiveness?
Comment by Ashley Marie — February 2, 2011 @ 8:46 pm
Hi Ashley,
As long as you have told your doctor you are on the nuvaring, your doctor would prescribe you a medication that will not interact with your birth control so you can treat your urinary tract infections. Cipro will not affect the nuvaring’s effectiveness.
Comment by Janine — February 3, 2011 @ 11:31 am
i’m 45 and have been on nordette for many years. I was on zithromax starting on 3/30 and had unprotected sex on fri 4/8. I thought I was safe, but now I’m in a panic! Please help!!! Don’t want to have a baby at 46!
Comment by teri — April 10, 2011 @ 5:48 am
Dear Teri,
When your doctor prescribed you to Zithromax, did you not let him/her know you are also on Nordette? Whenever your doctor is about to prescribe you with anything you have to let him/her know about all the medication you are currently taking, especially your birth control since you do not want a baby because your doctor would have prescribed you something else that would not interact with Nordette.
Right now I would suggest you to use back up contraception if you plan on having sex again. Then, make an appointment with your doctor to get you on to something else that will not interact with Nordette.
As for wondering if you are pregnant or not, I am not sure where you are on your cycle but I would suggest you finish off this pack and wait for your period. If you do get your period, you should be fine. If you don’t get your period, take a home pregnancy test first to see if it’s positive or negative and then make an appointment with your doctor and get a more accurate pregnancy test.
I hope this helps!
Comment by Janine — April 11, 2011 @ 4:01 pm
what about sulfamethoxazole and trimethoprim what are its affects on BC?
Comment by morgan — April 30, 2011 @ 2:24 pm
Dear Morgan,
I’m not sure which birth control you are on, but sulfamethoxazole and trimethoprim DOES interact with birth control pills! Make sure that you let your doctor know when he is prescribing you anything that you are on birth control.
Comment by Janine — May 3, 2011 @ 11:20 am
I have been on tri sprintec for about 4 yrs. My doctor gave me a ten day supply of ciprofloxacin 500mg for a uti. Will this affect my birth control? I start my new pack of pills this Sunday.
Comment by Amy — June 30, 2011 @ 9:56 pm
Dear Amy,
Ciprofloxacin will affect your birth control efficacy. I would advise you to use back up contraception (such as condoms or spermicide) for the next few weeks. Be sure in the future when your doctor is prescribing you medication to let him/her know you are on birth control pills and to prescribe you with another medication that will not interact with your birth control.
Comment by Janine — July 4, 2011 @ 9:45 am
Ive been on Tri Sprintec for 8 months and my doctor has just given me a 10 day supply of Nitrofurantoin Mono for my bladder infection. She said it should not interact my birth control but to be careful just in case. how long I should use a back up method?
Comment by Anon — August 14, 2011 @ 11:09 pm
Hi Anon,
It is recommend that you use the back up contraception for at least one week after stopping the antibiotics. Here is some more information about antibiotics – http://www.birthcontrolbuzz.com/blog/2006/07/can-antibiotics-affect-birth-control-pills.html
Comment by Janine — August 15, 2011 @ 10:23 am
Janine,
Thank you so much. This may be a ridiculous question, but I was wondering if it matters that I began the medication while I was on my menstrual cycle? And I won’t finish the medication until I’m on my sixth hormonal pill on a new pack.
Comment by Anon — August 15, 2011 @ 5:18 pm
Dear Anon,
No question is a ridiculous question! I do not think it matters when you start antibiotics, as long as you are using back up contraception during the time you are on the antibiotics and at least one week after stopping antibiotics, you should be protected.
Comment by Janine — August 17, 2011 @ 9:23 am
Dear Janine,
I was just worried because this is my first time taking any sort of antibiotics that could interfere with it and my doctor didn’t get into much detail. So thank you so much for your help!
Comment by Anon — August 17, 2011 @ 2:31 pm
Dear Anon,
No Problem. Glad I could help
Comment by Janine — August 17, 2011 @ 5:42 pm
Why is it stated in two different places the effects of ciprofloxacin where it contradicts itself? Either it does affect birth control, or it doesn’t. Which is the correct answer? I’m taking ciprofloxacin and have had unprotected intercourse with my long term mate while on ortho tri cyclen and I’m quite curious about Its effects but I can’t seem to find locate a steady answer.
Comment by Jessica — October 4, 2011 @ 6:20 pm
Dear Jessica,
If you are taking ciprofloxacin with ortho tri cyclen, it is highly recommended that you use back up contraception (ie. condoms, spermicide, etc) during the time you are on ciprofloxacin because the use of ciprofloxacin will decrease the efficacy of ortho tri cyclen.
Comment by Janine — October 5, 2011 @ 6:37 am
I started a tetracycline (doxycycline) yesterday. I also had unprotected sex yesterday. I was wondering how long after you start taking a antibiotic does it start to decrease the effectiveness of birth control. Can it lessen its effect the very first day?
Comment by Sam — October 8, 2011 @ 9:59 am
Dear Sam,
Yes, it decreases the effectiveness the first day of taking the antibiotic.
Comment by Janine — October 11, 2011 @ 9:38 am
Phenobarbital is not an antibiotic. It is an antiseizure medication that can also be used for anxiety. If you’re going to dispense medical information please attempt to make it accurate.
Comment by Aleah — October 16, 2011 @ 2:16 pm
Dear Aleah,
Thanks for letting us know it is not an antibiotic, I have updated our post. Phenobarbital is a medication that will interfere with birth control pills so definitely watch out!
Comment by Janine — October 17, 2011 @ 2:32 pm
Been on bc pill yaz for 3 yrs. This month on 4 oct I started taking cefuroxime antibiotics for a week. I had sex during taking antibtiotics. I didn’t vomit or have diahroea. Risk of pregnancy? period is on 31 oct.
Comment by abigail borg — October 22, 2011 @ 12:10 am
Dear Abigail,
The antibiotic cefuroxime does interfere with Yaz. Taking an antibiotic that interacts with your birth control pill does not normally make you vomit or have diarrhea. It only decreases the effectiveness of your birth control. Hopefully you do get your period on Oct 31, if not, take a pregnancy test. Next time your doctor prescribes you to any medication, make sure you let him/her know you are on yaz. That way he will prescribe you to an antibiotic that will not interact with your birth control pills. If unsure, always you back up contraception for extra protection in case you are not sure if the medication do interact with your birth control pill. Better be safe than sorry.
Comment by Janine — October 24, 2011 @ 9:57 am
I started taking antibiotics on the first day of my menstrual cycle, im taking Keflex and Bactrim DS, Im on birthcontrol pills.. Had sex days 1st,2nd, and 3rd day after my period (1 week) my doctor never mentioned using a back up so Im wondering if these anitbiotics will interfere with my pill.. Is there chances of me getting pregnant from those 3 days???
Comment by Loreen — December 7, 2011 @ 8:12 pm
Dear Loreen,
Keflex and Bactrim DS do interact with your birth control pills. Which pill were you on? If you started the antibiotics on the first day of your period, how long were you prescribed the antibiotics for?
If you were only prescribed for 1 week, then by the end of your cycle, you would have finished the antibiotics and started on your active birth control pills. If this is the case, you should be protected while you had sex the first few days of being back on the pill.
If you were prescribed antibiotics for more than a week, you continued taking antibiotics after your period and started active birth control pills, your risk for pregnancy is high. It may be too early for you to take a pregnancy test right now, you can wait for your period at the end of the month and if it doesn’t come, take the pregnancy then.
Before your doctor prescribes you to any medication, it is very important you remind him/her that you are on birth control pills.
Comment by Janine — December 8, 2011 @ 11:33 am
Does cefprozil affect aviane?
Comment by annonn — December 20, 2011 @ 8:22 pm
I have been on birth control for 7 yrs with no break. I am on an antibiotic that is listed above what would my odds be of becoming pregnant?
Comment by kristine — December 21, 2011 @ 9:06 am
Dear kristine,
If you had unprotected sex during the period you are on an antibiotic that interferes with your birth control, your risk for pregnancy increases. To find out if you are pregnant, you can wait for your next period to come. But since you are taking birth control pills with no break, you can take a pregnancy test in a few weeks.
Comment by Janine — December 21, 2011 @ 9:50 am
Dear annonn,
Cefprozil does affect aviane. If you are about to take this antibiotic, make sure you use back up contraception during the time you are on this antibiotic.
Comment by Janine — December 21, 2011 @ 10:08 am
Hello I had unprotected sex while on ciprofloxacin but it happened at the very end of my antibiotic (last pill). I have been on ortho tri cyclen lo for 6 years. i am on the 3rd week of my pills. is there a chance that I could be pregnant?
thank u
Comment by Gina — December 26, 2011 @ 11:19 pm
Does Amox TR-K Clv 875-125mg effect nuvring any?
Comment by Stephanie — December 29, 2011 @ 8:22 am
Dear Stephanie,
I am not sure what Amox TR-K Clv 875-125mg is except it may be an antiobiotic that is 125 mg. I am thinking you are taking either lansoprazole/ amoxicillin/ clarithromycin. In this case any one of lansoprazole/ amoxicillin/ clarithromycin will affect the effectiveness of Nuvaring. When your doctor prescribed you this antibiotic, it is very important you inform your doctor that you are on the NuvaRing, so that he/she will prescribe you to an antibiotic that will not decrease the effectiveness of NuvaRing.
Comment by Janine — January 4, 2012 @ 3:45 pm
Dear Gina,
There is a chance you are pregnant. When your doctor prescribes you to an antibiotic, it is VERY IMPORTANT you inform your doctor that you are on Ortho Tri Cyclen. The ciprofloxacin that your doctor prescribes you interacts with your birth control pill. In other words, the antibiotic (ciprofloxacin) that you are currently taking is decreasing the effectiveness of your birth control (ortho tri cyclen). During the time you are on the antiobiotic, you are basically not protected at all. Definitely take a pregnancy test in a few weeks to see if you are pregnant.
Comment by Janine — January 4, 2012 @ 3:53 pm
Does ortho tri cycle interact with nitofurantion macro?
Comment by Joanna — January 14, 2012 @ 2:27 pm
Dear Joanna,
Yes Ortho Tri Cyclen does interact with Nitrofurantoin.
Comment by Janine — January 16, 2012 @ 9:25 am
I took amoxicillin for bout a day – 2days while being on BCP (almst a year).. 2 days after-wards I had unprotected sex. Does da chance of being pregnant increase by a lot. And so, should I get tested n when?
Comment by Anna — January 18, 2012 @ 5:23 pm
Dear Anna,
There is a chance that you can be pregnant. Whenever you are taking antibiotics and you’re unsure whether it interferes with your birth control pills, use back up birth control (ie. condoms or spermicide) during the time you are taking antibiotics to a week or two after you have stopped taking antibiotics. To find out if you are pregnant, you should wait for your period. If you don’t get your period, take a pregnancy test.
Comment by Janine — January 19, 2012 @ 12:02 pm
I have been on birth control (Reclipsen) for a few years. I had unprotected sex on Sunday and I started taking Avelox today (Wednesday). Can I still get pregnant from the unprotected sex on Sunday? I asked my pharmacist if the two medications affect each other and she said no. I’m just worried about the chances of getting pregnant before I started the antibiotic.
Comment by Nicole — January 24, 2012 @ 2:53 pm
Does nuvaring and cefprozil interact to change effectiveness of birth control?
Comment by sarah — January 25, 2012 @ 4:17 am
Dear Sarah,
Cefprozil does not decrease the effectiveness of the Nuvaring. You are safe
Comment by Janine — January 25, 2012 @ 9:35 am
Dear Nicole,
Avelox does decrease the effectiveness of Reclipsen so I would advise you to use back up birth control (ie. condoms or spermicide) while on the antibiotic until a week after you have stopped taking Avelox. Since you have been taking Reclipsen for the past few years, if you have been taking it diligently every day around the same time every day, then chances of you getting pregnant last Sunday is slim. If you are worried, I would advise you to take a pregnancy test in a few weeks.
Comment by Janine — January 25, 2012 @ 9:43 am
I am taking Crystelle ( I think that’s how you spell it). I have been taking an antibiotic since the first day of my period. it wad the third day. when my boyfriend and I finished having sex, as he pulled out the condom was still inside at least an inch. even if a small drop of seman was on the edge of my vaginia( I wiped it out the best I could) am I at high risk for pregnancy. and what are spermicides ?? please reply.
thank you
Comment by Shelly — January 27, 2012 @ 8:12 pm
Im on the second week of my bith control pills and started Zythromax today for 5days. 500mg. today then 250mg.x4days. should i use protection and for how long?
Comment by darlene — January 29, 2012 @ 6:40 pm
Dear darlene,
I would advise you use back up contraception (ie. condoms or spermicide) during the time you are on Zithromax until a week after you have stropped the antibiotics just in case.
Comment by Janine — January 30, 2012 @ 9:39 am
Dear Shelly,
If you can tell us which antibiotic you are on that would help us know whether or not it interacts with your birth control and that if you are at high risk of pregnancy.
Spermicide prevents pregnancy by killing sperm with a chemical called nonoxynol-9. Before intercourse, the contraceptive is placed on the entrance of the uterus where sperm are trapped by the foam or gel barrier on the contraceptive which then gets destroyed by the chemical nonoxynol-9. For more information, on the last paragraph of this blog post, we talked about Spermcide: http://www.birthcontrolbuzz.com/blog/2010/10/contraceptive-alternatives-mechanical-barriers.html
Comment by Janine — January 30, 2012 @ 9:54 am
I’m on amoxicillin
Comment by Shelly — January 31, 2012 @ 2:00 pm
Dear Shelly,
If you are on amoxicillian and birth control pills, then you should use back up contraceptives such as condoms or spermicide during the time you are on amoxicillian and continue to use back up contraception until a week after you have stopped the antibiotic.
Comment by Janine — February 1, 2012 @ 2:15 pm
I am taking a 20 day anti.. smz/tmp generic for bactrum i guess. From wat i understand it can effect it slightly but not as definate as the list above i had unprotected sex 3 times since being on this pill while usin the not so effective pull out method along with tri sprentec os thete a caution???
Comment by d — February 7, 2012 @ 5:47 pm
Hey,
I’m just wanting a second opinion, as I asked another doctor but I’m still a bit unsure about the information I received. I have been told that taking 500mg Amoxil won’t affect my Microgynon 50 pill, as long as I don’t take antibiotics for longer than 3 weeks.
Is this true?
Thanks
Comment by Kelly — February 8, 2012 @ 12:09 am
Dear Kelly,
Amoxil does decrease the effectiveness of birth control pills, including Microgynon 50. Make sure that you use back up contraception during the time you are on Amoxil and continue to use back up contraception until a week after you have stopped taking Amoxil.
Comment by Janine — February 8, 2012 @ 9:50 am
Dear d,
The antibiotic you are taking (generic alternative of Bactrim) decreases the effectiveness of Tri Sprintec. You need to be using back up birth control (ie. condoms or spermicide) while you are on antibiotics up until a week after you have stopped taking the antibiotics.
Comment by Janine — February 8, 2012 @ 10:14 am
I am taking cephalexin and i am finishing my dose today.how long will it affect my birth control
Comment by Rachel — February 10, 2012 @ 11:13 am
I had been sick and went to the doctor over a week ago. They had it in their system that I was on tri-sprintec and I even confirmed I was still taking it. They had prescribed me AMOX TR-K CLV 875-125 MG without mentioning anything to me about how it might react with my birth control. I didn’t realize it could affect it until a show I had been watching mentioned that antibiotics affect bc and I started googling it not too long ago. While taking the antibiotic, I had sex with my bf, should I be worried?
Comment by AK — February 14, 2012 @ 7:11 pm
Dear Rachel,
Cephalexin will decrease the effectiveness of the birth control you are taking. Use back up birth control during the whole time you are on Celphalexin and continue to use back up contraception until a week after you have already finished your antibiotics. Next time, let your doctor know you are on birth control and he/she will prescribe you to an antibiotic that will not interact with your birth control pills.
Comment by Janine — February 15, 2012 @ 10:24 am
I had Tinidazole therapy last Friday, I took 4 pills. On Saturday I started the second pack of birth control pills, and I had unprotected sex on Tuesday, 4 days after the end of antibiotics therapy…Was the effectiveness of birth control decreased?
Comment by Elventree — February 16, 2012 @ 9:43 am
Dear Elventree,
Tinidazole does decrease the effectiveness of birth control pills and usually we recommend girls to continue using back up contraception a week after you stopped antibiotics. There is a small chance you may have gotten pregnant when you had unprotected sex 4 days after the antibiotics therapy. Wait for your period to come at the end of your pack. If you got your period, you are most likely not pregnant. If you didn’t get your period, take a pregnancy test.
Comment by Janine — February 16, 2012 @ 10:03 am
Hello everyone,
I’m not entirely sure how active this forum is as of now, but I wanted to double check something. I’m on the birth control pill Cilest and my doctor has prescribed me Nitrofurantoin tablets (50 mg/4 tablets daily over 3 days)to get rid of a UTI. I was told by her that the tablets would not interfere with the effectiveness of the BCP unless they caused me to vomit or have tummy problems. Now I’m a bit unsure of what to do…
Comment by Sarie — February 27, 2012 @ 5:02 pm
Dear Sarie,
It seems that the antibiotic Nitrofurantoin does interfere with Cilest. You can always get a second opinion from either another doctor or even the pharmacist to ensure that the antibiotics decreases the effectiveness of birth control pills. What you can also do for extra protection is to use back up contraception during the time you are on Nitrofurantoin up until a week after you have stopped Nitrofurantoin.
Comment by Janine — February 28, 2012 @ 10:04 am
Does Fluconazole effect birth control pills?
Comment by Jill — March 9, 2012 @ 9:17 pm
Does cipro affect Kariva Birth control pills?
Comment by Jill — March 9, 2012 @ 9:18 pm
Dear Jill,
Fortunately, Fluconazole does not effect birth control pills. You are safe to take them both together.
Comment by Janine — March 12, 2012 @ 9:13 am
Dear Jill,
Kariva does not effect birth control pills. You are safe to take them together
Comment by Janine — March 12, 2012 @ 9:19 am
I’m on a low dose amoxicillin for acne and on the pill. I’m having unprotected sex with my boyfriend right now. Should I stop taking the antibacterial? I’m only in my second month of usin the pill, but the first month I didn’t spot, and this month I have been spotting ever since the time changed. Should I have taken my pills at the same biological time as normal? Because I changed the time I take the pills to reflect the time change. If that’s bad, should I change back to when my body was used to, or keep going at this time and let it adjust?
Comment by Mary — March 16, 2012 @ 6:23 am
Dear Mary,
The time change is not what is causing your spotting, it’s the low dose amoxicillin. Amoxicillin decreases the effectiveness of the pill and if you are having unprotected sex with your boyfriend during the time you are taking both Amoxicillin and birth control pill, I would advise you to use back up contraception (ie. condoms or spermicide) during the time you are on Amoxicillin and take a pregnancy test in a few weeks to see if you have gotten pregnant from the time you were having unprotected sex while taking the antibiotic and the pill together. When you are being prescribed new medication, it is very important you let your prescribing doctor know that you are on birth control pills so that he will not prescribe you with a medication that will interact with the pill.
If your doctor had only prescribed you to Amoxicillin for a small period of time, then use back up contraception during the time you are on Amoxicillin until a week after you have stopped taking it to be safe. But if your doctor wants you to stay on Amoxicillin continuously, I would advise you meet with him/her again and get him/her to prescribe you to another medication to treat your acne.
Comment by Janine — March 16, 2012 @ 10:41 am
So last Saturday (3/10) I finished taking antibiotics for a bladder infection (1 pill 2x daily for 3 days). I am on a low dosage of birth control pills Then Friday (3/17) my boyfriend and I had unprotected sex, should I be worried that the effects of the antibiotics messed up my birth control?
Comment by Em — March 18, 2012 @ 3:53 pm
Dear Em,
It has been a week since you came off the antibiotics, I think you should be protected. If you are worried, you can take an emergency contraceptive just in case, but I’m pretty sure you are fine.
Comment by Janine — March 19, 2012 @ 10:45 am
Does the antibiotic stromectol affect the birth control pill?
Comment by Bianca — March 28, 2012 @ 9:16 am
Dear Bianca,
Stromectol does not affect the birth control pill.
Comment by Janine — March 28, 2012 @ 9:40 am
Can you tell me if generic Bactrim will interfere with my generic Yaz? Thank you so much!
Comment by Jamie — March 29, 2012 @ 5:55 pm
Dear Jamie,
Bactrim does interfere with generic Yaz. Please use protection while on Bactrim.
Comment by Janine — March 30, 2012 @ 2:29 pm
Hi! I know someone posted earlier with a question on low dose nitrofur (50 mg) to treat frequent UTIs. I am not on a course of it, I can just take it after sex. I am on seasonique birth control and was just wondering if taking a nitro pill the next morning would decrease my protection. Thanks!
Comment by lauren — March 31, 2012 @ 8:32 am
Hi! I noticed that earlier someone asked about a low does nitrofuran (50 mg) interfering with their nuvaring, however I was curious if it would interfere with my seasonique birth control. I am not on a course of these antibiotics, they are used to treat frequent UTI’s and I can just take them after sex. However, I was wondering if I didn’t not use any other form of birth control expect my seasonique and then took the antibiotic the next morning if my chances of getting pregnant would increase. Thanks!
Comment by Lauren — March 31, 2012 @ 4:56 pm
Dear Lauren,
Nitrofuran does interefere with the effectiveness of Seasonique. I would advise you to get another prescription of antibiotics to treat frequent UTI’s. Seasonique is used to prevent pregnancy after unprotected sex, if you are taking Nitrofuran every time after you had sex, Nitrofuran decreases the effectiveness of Seasonique every time after you have had sex so your chances of becoming pregnant would be increased. Again, I would suggest you meet with your doctor to get a prescription for another antibiotic to treat the frequent UTI.
Comment by Janine — April 2, 2012 @ 6:57 am
Dear Lauren,
Nitrofuran does interefere with the effectiveness of Seasonique. I would advise you to get another prescription of antibiotics to treat frequent UTI’s. Seasonique is used to prevent pregnancy after unprotected sex, if you are taking Nitrofuran every time after you had sex, Nitrofuran decreases the effectiveness of Seasonique every time after you have had sex so your chances of becoming pregnant would be increased. Again, I would suggest you meet with your doctor to get a prescription for another antibiotic to treat the frequent UTI.
Comment by Janine — April 2, 2012 @ 6:57 am
I started taking Metronidazole on Monday. I had unprotected sex the Saturday before and this past Saturday while still on the prescription.
I was wondering what my chances are of becoming pregnant? My doctor told me that it doesn’t effect my birth control pills… Is this true?
Comment by Gc — April 29, 2012 @ 5:23 pm
Dear Gc.
I’m not sure which birth control you are on, but it seems that Metronidazole interacts with most of the mainstream birth control pills such as Yaz, Alesse, Seasonique, Loestrin 24 fe, etc. If you are on any of those listed birth control pills, I would advise you to use back up contraception during the entire time you are on Metronidazole. It is always better to be safe than sorry. Since you had unprotected sex while on Metronidazole, wait for your period to come at the end of the month. If you don’t get your period, take a pregnancy test. If negative, you should be fine, but just in case you can also take a more accurate test at the doctor’s office.
Comment by Janine — April 30, 2012 @ 9:57 am
hey i was on augmentin for 7 days and i hav finished them 8 days ago shud i be ok now?? im takin cilest
Comment by jen — May 1, 2012 @ 11:10 am
HI I started taking metronidazole last Friday and that sunday got my period. I’m the type to get nerveous about everything so my period for the first time is so so light almost not normal for me? I’m wondering if the antibiotics could have anything to do with it? Also Im taking Aviane-28 tablet birth control bills and have been having unprotected sex while on the medication. If I could be pregnant I would obviously not know now because it would be to soon. I start taking my new pack of pills sunday if I could be pregnant will this effect the baby in any sort of way?
Comment by ALLISON — May 2, 2012 @ 8:29 am
Dear jen,
You should be okay. Did you use back up contraception while you were on Augmentin? If you did then you should definitely be okay by now
Comment by Janine — May 2, 2012 @ 11:02 am
Dear Allison,
Metronidazole is interacting with your birth control pill, this is why you got light bleeding on Sunday. If you are still on Metronidazole, I would advise you to use back up contraception while on Metronidazole. Taking Aviane should not affect the baby if you have conceived during the time you had unprotected sex while on Metronidazole. Take a pregnancy test in a few weeks to see if you are pregnant. If the test is positive, get another more accurate test at your doctor’s to confirm your pregnancy. If the test is negative, then you should be fine and make sure you use back up contraception whenever you take antibiotics or any medication you think may interact with your birth control pill. Better to be safe than sorry.
Comment by Janine — May 2, 2012 @ 11:15 am
while i was on the augmentin i was to sick to do anytin ha and for 8 days after i done notin to! just makin double sure i be grand
Comment by jen — May 3, 2012 @ 2:38 am
Hi, I’m on levora birth control pills and I started taking sulfamethoxazole/trimethoprim 160mg wednesday the day before my cycle started. I started a new pack on Sunday and had unprotected sex today is there a chance I could get pregnant? Also, how long after I’m done with my 10 day antibiotics can I start having unprotected sex?
Comment by Raquel — May 7, 2012 @ 9:28 pm
Dear Raquel,
Sulfamethoxazole/trimethoprim does interact with Levora, you need to use back up contraception while on sulfamethoxazole/trimethoprim. I would advise you to continue using back up contraception until a week after you have stopped sulfamethoxazole/trimethoprim. Chances you have gotten pregnant from Sunday is very high. Wait until you get your period at the end of this pack. If you don’t get your period, take a pregnancy test. If the test comes out positive, get a more accurate test done with your doctor.
Comment by Janine — May 8, 2012 @ 11:00 am
I was wondering would it be possible to get pregnant while taking a high dose of birth control and bactrim
Comment by Alex — May 15, 2012 @ 11:02 am
Dear Alex,
It is possible for you to get pregnant while taking a high dose birth control and bactrim without using any back up contraception (ie. condoms or spermicide). Bactrim interacts with birth control pills. I would advise you to use back up contraception while you are on Bactrim and continue taking it a week after you have stopped taking the antibiotic.
Comment by Janine — May 16, 2012 @ 2:31 am