Azithromycin

 Risk Factor: BM
 Class: ANTI-INFECTIVES / Antibiotics/Anti-infectives

Contents of this page:

Fetal Risk Summary
Breast Feeding Summary
References
Questions and Answers

Fetal Risk Summary

Azithromycin, an azalide antibiotic that is categorized as a member of the macrolides, is derived from erythromycin. Animal studies using mice and rats treated with doses up to maternal toxic levels (i.e., 200 mg/kg/day) revealed no impairment of fertility or harm to the fetus (1).

Azithromycin crosses the human placenta at term (2,3). In 20 women scheduled for elective cesarean section, a single 1-g oral dose of azithromycin was given 6 (N=2), 12 (N=7), 24 (N=5), 72 (N=5), or 168 (N=1) hours before delivery. The mean maternal concentrations at delivery for the five groups were 311, 144, 63, 60, and <10 ng/mL, respectively, where as the corresponding mean cord serum levels were 19, 26, 27, 19, and <10 ng/mL, respectively. Cerebrospinal fluid levels in the mothers (all had spinal anesthesia) were undetectable (<16 ng/mL) in each group.

In an ex vivo experiment with term human placentas utilizing a single placental cotyledon model, the mean transplacental transfer of three macrolide antibiotics (azithromycin, erythromycin, and roxithromycin) were 2.6%, 3.0%, and 4.3%, respectively (3). The percentages were calculated as the ratio between the steady state level in fetal venous and maternal arterial sides (3).

A number of reports have described the use of azithromycin in human pregnancy, but in only one of the studies (10) was the drug used early in gestation (4,5,6,7,8,9 and 10). A 1994 abstract reported that 16 pregnant patients with cervicitis caused by chlamydia had been treated with a single 1-g oral dose of the antibiotic in a comparison trial with erythromycin (4). Fifteen of the women had negative tests for chlamydia after treatment. No data were given on gestational age at the time of treatment or on the pregnancy outcomes. In a second, similar report, also comparing efficacy with erythromycin, 15 pregnant women with chlamydial cervicitis were treated with a single 1-g oral dose (5). All of the women had negative cervical swabs for chlamydia as analyzed by direct DNA assay 14 days after the dose. Three more recent reports have also documented the efficacy of azithromycin in the treatment of pregnant women with chlamydia (6,7 and 8). Of the five reports, only the last study (8) indicated the gestational age at treatment (about 24 weeks'), but none provided information on fetal outcome. In contrast to the effectiveness of azithromycin for chlamydia infections, a single 1-g oral dose of the antibiotic was ineffective in reducing lower genital colonization with ureaplasma in pregnant women between 22 and 34 weeks' gestation with ruptured membranes or preterm labor (9).

A 1998 noninterventional observational cohort study described the outcomes of pregnancies in women who had been prescribed one or more of 34 newly marketed drugs by general practitioners in England (10). Data were obtained by questionnaires sent to the prescribing physicians one month after the expected or possible date of delivery. In 831 (78%) of the pregnancies, a newly marketed drug was thought to have been taken during the 1st trimester with birth defects noted in 14 (2.5%) singleton births of the 557 newborns (10 sets of twins). In addition, two birth defects were observed in aborted fetuses. However, few of the aborted fetuses were examined. Azithromycin was taken during the 1st trimester in 11 pregnancies. The outcomes of these pregnancies were 1 elective abortion and 10 normal, term babies (10).

Although no congenital malformations were observed in the above study, the data are too limited to assess the safety of azithromycin. Moreover, the study lacked sensitivity to identify minor anomalies because of the absence of standardized examinations. Late appearing major defects may also have been missed due to the timing of the questionnaires. However, macrolide antibiotics are not considered to be major human teratogens.

Breast Feeding Summary

Azithromycin accumulates in breast milk (11). A woman, in the 1st week after a term vaginal delivery, was treated with a single 1-g oral dose of azithromycin for a wound infection following a bilateral tubal ligation and then, because of worsening symptoms, given 48 hours of IV gentamicin and clindamycin. She was discharged from the hospital on a 5-day course of azithromycin, 500 mg daily, but only took three doses because she wanted to resume breast feeding that had been stopped during azithromycin therapy. The patient continued pumping her breasts during this time to maintain milk flow and resumed breast feeding 24 hours after the third dose of the antibiotic. Drug doses and approximate time from the first dose were 1 g (0 hours), 500 mg (59 hours), 500 mg (83 hours), and 500 mg (107 hours). Milk concentrations of azithromycin and times from the first dose were 0.64 g/mL (48 hours), 1.3 g/mL (60 hours), and 2.8 g/mL (137 hours) (maternal serum concentrations were not determined). The authors attributed the antibiotics milk accumulation to its lipid solubility and ion trapping of a weak base.

References

1. Product information. Zithromax. Pfizer Labs, 1994.
2. Ramsey PS, Vaules MB, Vasdev G, Andrews WW, Ramin KD. Maternal and transplacental pharmacokinetics of azithromycin (abstract). Am J Obstet Gynecol 2000;182:S98.
3. Heikkinen T, Laine K, Neuvonen PJ, Ekblad U. The transplacental transfer of the macrolide antibiotics erythromycin, roxithromycin and azithromycin. Br J Obstet Gynaecol 2000;107:7705.
4. Edwards M, Rainwater K, Carter S, Williamson F, Newman R. Comparison of azithromycin and erythromycin for Chlamydia cervicitis in pregnancy (abstract). Am J Obstet Gynecol 1994;170:419.
5. Bush MR, Rosa C. Azithromycin and erythromycin in the treatment of cervical chlamydial infection during pregnancy. Obstet Gynecol 1994;84:613.
6. Rosenn M, Macones GA, Silverman N. A randomized trial of erythromycin and azithromycin for the treatment of chlamydia infection in pregnancy (abstract). Am J Obstet Gynecol 1996;174:410.
7. Wehbeh H, Ruggiero R, Ali Y, Lopez G, Shahem S, Zarou D. A randomized clinical trial of a single dose of zithromycin in the treatment of chlamydia among pregnant women (abstract). Am J Obstet Gynecol 1996;174:361.
8. Wehbeh HA, Ruggeirio RM, Shahem S, Lopez G, Ali Y. Single-dose azithromycin for chlamydia in pregnant women. J Reprod Med 1998;43:50914.
9. Ogasawara KK, Goodwin TM. Efficacy of azithromycin in reducing lower genital ureaplasma colonization in women at risk for preterm delivery (abstract). Am J Obstet Gynecol 1997;176:S57.
10. Wilton LV, Pearce GL, Martin RM, Mackay FJ, Mann RD. The outcomes of pregnancy in women exposed to newly marketed drugs in general practice in England. Br J Obstet Gynaecol 1998;105: 8829.
11. Kelsey JJ, Moser LR, Jennings JC, Munger MA. Presence of azithromycin breast milk concentrations: a case report. Am J Obstet Gynecol 1994;170:13756.
    
    

Questions and Answers

Antibiotics while pregnant? Azithromycin.?

I went to the doc, probably have a sinus infection etc, so she put me on the antibiotic Azithromycin it's a 6 tablet dose. I've never been on this type of antibiotic before, since it's only 6 doses, it must be strong. My concern is do you think it's safe for pregnancy? Have your doc perscribed you an antibiotic while pregnant? I told her I was pregnant & she was going to have me take sedafed (I think) but decided not to cuz she says she doesn't like to perscribe meds to pregnant women without them asking their ob/gyn first. That's why I'm concerned about the antibiotic. Docs office is closed. I don't think she'd prescribe something she had concerns about, but I'm concerned about the strength of it, don't know if that matters w/ being pregnant or not.

...How far along are you? Usually the highest risk is during the first trimester. When a medication is prescribed to a pregnant woman, the doctor has to weigh the benefits vs the risk of the treatment. We only prescribe when the benefits outweigh the risks. That said, azithromycin is widely used in pregnancy.

9 weeks pregnant and on Azithromycin?

This is the second time I got sick within the last 3 months. I have a bad cold, cough and a bit feverish. My OBGYN prescribed Azithromycin. She said if I get a fever its not good for the baby so its better to take medication before it get worse.

I've heard antibiotics are not safe during pregnancy. Is anyone else faced a similar question.

Thank you.

I am om my second round of the Azythromycin in the past month and I am currently 17 weeks along. I am a teacher and exposed to constant things every day and I haven't been able to shake this cough and congestion thing. My ob said that your immune system is actually down when you are pregnant! GREAT! Because we don't go through enough! Anyway, she also said that it is one of the safest choices for antibiotics and your baby is in more danger if you stay sick or get worse. Rest easy, you are ok. Hope you (and I) feel better soon!

Co-Azithromycin Chlamydia 39 Weeks Pregnant?

im 39 weeks pregnant and i just took a drug called co-azithromycin i had to take all 8 tablets at one time its a 250 mg pill each tablet. my doc said to take them as soon as possible because im due in two days and he wants to cure my chlamydia before the baby comes i called mother risk and asked about it and they said it should be fine because your almost due so the baby wont be harmed, but my question is what are the side effects of this drug? can this drug cause me any serious harm? has anyone taken this drug and the exact doseage as i did and if so what are the side effects should i be worried???

Did they test you during your first exam? I'm just wondering if so why would they wait to give you the meds now - unless you had sexual relations during the pregnancy to contract Chlamydia?
There should be no side effects because azithromycin is an antibotic, so it would be something to take of you were really sick too. (to think of it that way). Also, your doctor would prescribe you something that would defintely not effect your child - it's why most pregnant women have different meds given to them for that fact alone. They may also due a C-section just to be on the safe side too.

Side note: I did try to locate the antibotic you are on but the name pulls up with many leads in WebMD - below is a link that provides each of those drugs. It should list any side effects.

is it safe for pregnant women to take azithromycin?

it is commonly used in pregnancy to treat infection, attatched link with relevant information

I am 25 weeks pregnant and I am under antibiotic treatment with azithromycin. Would my baby be safe?

I have been suffering from severe coughs and upper respiratory infection symptoms for almost a week. I went to see the doctor twice already and found no evidence of strep in my throat twice. However, the increasing intensity of coughs kept me awake all night for last two days. I am now 25 weeks pregnant and avoided taking any meds but due to the condition I started taking azithromycin antibiotics today. After some hours of taking this med I started to cough again severely and still kept me awake all night. It's worse at night that I constantly spit white foamy mucus from my throat and this cough really drains me out. My muscles hurt and tummy feels very uncomfortable. I am really worried if my baby's okay with all this I am going through. Even my feet and hands started to swell with the feeling of loose ligaments/joints, which this is probably due to the pregnancy. I feel terrible with all these conditions and wonder if baby's okay. My baby seem to move around less now. Help me!

Azithromycin (Zithromax®) is considered a pregnancy Category B medicine by the U.S. Food and Drug Administration (FDA), which means that it has not been studied in pregnant women. However, when studied in pregnant animals, azithromycin showed no negative effects on unborn babies.

The U.S. Food and Drug Administration (FDA) uses a pregnancy category system to classify the possible risks to a fetus when a specific medicine is taken during pregnancy. Pregnancy Category B is given to medicines that have not been studied in pregnant humans but do not appear cause harm to the fetus in animal studies.

However, it is important to note that animals do not always respond to medicines the same way that humans do. Therefore, a pregnancy Category B medicine may be given to a pregnant woman if her healthcare provider believes that its benefits outweigh any possible risks to her unborn child.

If you are pregnant and have been prescribed azithromycin, let your healthcare provider know. He or she will consider both the benefits and risks of azithromycin during pregnancy before making a recommendation for your particular situation.

Will a second dose of Azithromycin for Chlamydia still work?

I am 11 weeks pregnant and a week after routine tests I was told I has Chlamydia. I was given Azithromycin, two tablets as a single dose. It has been 3 weeks since taking them and I don't think they have worked, as I find it hard to keep food down and was sick not long after taking the pills. I am wondering if I have to take the antibiotics again will they still be effective or will I need something stronger?

First, at 11 weeks pregnant, it is not uncommon to have constant nausea and even frequent vomiting - that is related to the pregnancy and probably has nothing to do with the chlamydia. When you get into your 2nd trimester, the nausea will usually go away. The antibiotics you took should have cured the chlamydia so you do not need any more antibiotics. You should have a prenatal check-up coming up soon - visit with your OB doctor about your concerns or, even easier - give his nurse a call and she will talk with him about your concerns and call you back.

Can I get pregnant while on pill after taking Zithromax?

I have been on the pill for four years and was prescribed azithromycin for a cold. I asked the pharmacist and he said it wasn't necessary to use back up birthcontrol. Well, we did use a condom until the week I was to start my period (that monday we didn't use anything... then i started my period on Wednesdsay ) so obviously we didn't do anymore.... until after. Basically what I am asking is... my period is due to start next week but i have spotted a little this week, my breasts are a little sensitive, and my hair seems to be flaling out.. All symptoms of pregnancy. Anyone offer any insight as to whether you know if zithromax decreases the effectiveness? And how easy would it be to get pregnant if it did.... I know i should just take a preg. test but I am scared!

According to what I've read, Zithromax isn't supposed to affect birth control pills. Also, you seem to be saying that you used back-up anyway and got your period last month, as usual. If that's the case, try not to worry yourself. If you are late, then take a home pregnancy test. In the meantime, try to relax and not worry. Stress can end up delaying your period which will make you worry more!

How long to wait after taking Azithromycin before having sex?

I am 6 months pregnant and at a recent visit to my doctor they diagnosed me with ureaplasma. My husband and I have both been treated now, but we are not sure when we can go back to having sex? Even with a condom? Wondering if anyone had any info. Also does anyone know if this can be spread through oral sex?

Take 10 days to clear up an infection. Take all of your medication. Call your doctor, get his advice.