Cephalexin

 Risk Factor: BM
 Class: ANTI-INFECTIVES / Cephalosporins

Contents of this page:

Fetal Risk Summary
Breast Feeding Summary
References
Questions and Answers

Fetal Risk Summary

Cephalexin is an oral, semisynthetic cephalosporin antibiotic. Reproduction studies found no evidence in rats, at doses up to 500 mg/kg, found no evidence of impaired fertility or reproductive performance or, in mice and rats, of fetal harm (1).

Several published reports have described the administration of cephalexin to pregnant patients in various stages of gestation (2,3,4,5,6,7,8,9,10 and 11). None of these have linked the use of cephalexin with congenital defects or toxicity in the newborn. However, even though cephalosporins are usually considered safe to use during pregnancy, a surveillance study described below found results contrasting to the published data.

In a surveillance study of Michigan Medicaid recipients involving 229,101 completed pregnancies conducted between 1985 and 1992, 3,613 newborns had been exposed to cephalexin during the 1st trimester (F. Rosa, personal communication, FDA, 1993). A total of 176 (4.9%) major birth defects were observed (154 expected). Specific data were available for six defect categories, including (observed/expected) 44/36 cardiovascular defects, 11/5 oral clefts, 3/2 spina bifida, 3/10 polydactyly, 1/6 limb reduction defects, and 8/9 hypospadias. The data for total defects, cardiovascular defects, and oral clefts are suggestive of an association between cephalexin and congenital defects, but other factors, such as the mother's disease, concurrent drug use, and chance, may be involved. However, similar findings were measured for another cephalosporin antibiotic with more than a thousand exposures (see Cefaclor). Positive results were also suggested for cephradine (339 exposures) but not for cefadroxil (722 exposures) (see Cephradine and Cefadroxil). In contrast, other antiinfectives with large cohorts (see Ampicillin, Amoxicillin, Penicillin G, Erythromycin, and Tetracycline) had negative findings.

Transplacental passage of cephalexin has been demonstrated only near term (2,3). Following a 1-g oral dose, peak concentrations for maternal serum, cord serum, and amniotic fluid were about 34 (1 hour), 11 (4 hours), and 13 mg/mL (6 hours), respectively (3). Patients in whom labor was induced were observed to have falling concentrations of cephalexin in all samples when labor was prolonged beyond 18 hours (4). In one report, all fetal blood samples gave a negative Coombs' reaction (2).

The effect of postcoital prophylaxis with a single oral dose of either cephalexin (250 mg) or nitrofurantoin macrocrystals (50 mg) starting before or during pregnancy in 33 women (39 pregnancies) with a history of recurrent urinary tract infections was described in a 1992 Reference (11). A significant decrease in the number of infections was documented without fetal toxicity.

The manufacturer has unpublished information on 46 patients treated with cephalexin during pregnancy (C.L. Lynch, personal communication, Dista Products, 1981). Two of these patients received the drug from 12 months prior to conception to term. No effects on the fetus attributable to the antibiotic were observed. Follow-up examination on one infant at 2 months was normal.

Breast Feeding Summary

Cephalexin is excreted into breast milk in low concentrations. A 1-g oral dose given to six mothers produced peak milk levels at 45 hours averaging 0.51 mg/mL (range 0.240.85 mg/mL) (12). Mean milk:plasma ratios at 1, 2, and 3 hours were 0.008, 0.021, and 0.14, respectively. Even though these levels are low, three potential problems exist for the nursing infant: modification of bowel flora, direct effects on the infant, and interference with the interpretation of culture results if a fever workup is required. Although not specifically listing cephalexin, the American Academy of Pediatrics classifies other cephalosporin antibiotics as compatible with breast feeding (13).

References

1. Product information. Keflex. Dista Products, 1997.
2. Paterson ML, Henderson A, Lunan CB, McGurk S. Transplacental transfer of cephalexin. Clin Med 1972;79:224.
3. Creatsas G, Pavlatos M, Lolis D, Kaskarelis D. A study of the kinetics of cephapirin and cephalexin in pregnancy. Curr Med Res Opin 1980;7:436.
4. Hirsch HA. Behandlung von harnwegsinfektionen in gynakologic und geburtshilfe mit cephalexin. Int J Clin Pharmacol 1969;2(Suppl):1213.
5. Brumfitt W, Pursell R. Double-blind trial to compare ampicillin, cephalexin, co-trimoxazole, and trimethoprim in treatment of urinary infection. Br Med J 1972;2:6736.
6. Mizuno S, Metsuda S, Mori S. Clinical evaluation of cephalexin in obstetrics and gynaecology. In Proceedings of a Symposium on the Clinical Evaluation of Cephalexin, Royal Society of Medicine, London, June 2 and 3, 1969.
7. Guttman D. Cephalexin in urinary tract infections-preliminary results. In Proceedings of a Symposium on the Clinical Evaluation of Cephalexin, Royal Society of Medicine, London, June 2 and 3, 1969.
8. Soto RF, Fesbre F, Cordido A, et al. Ensayo con cefalexina en el tratamiento de infecciones urinarias en pacientes embarazadas. Rev Obstet Ginecol Venez 1972;32:63741.
9. Campbell-Brown M, McFadyen IR. Bacteriuria in pregnancy treated with a single dose of cephalexin. Br J Obstet Gynaecol 1983;90:10549.
10. Jakobi P, Neiger R, Merzbach D, Paldi E. Single-dose antimicrobial therapy in the treatment of asymptomatic bacteriuria in pregnancy. Am J Obstet Gynecol 1987;156:114852.
11. Pfau A, Sacks TG. Effective prophylaxis for recurrent urinary tract infections during pregnancy. Clin Infect Dis 1992;14:8104.
12. Kafetzis D, Siafas C, Georgakopoulos P, Papadatos CJ. Passage of cephalosporins and amoxicillin into the breast milk. Acta Paediatr Scand 1981;70:2858.
13. Committee on Drugs, American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 1994;93:13750.
    
    

Questions and Answers

Is there any side effect for a pregnant woman taking cephalexin tablet?

I am 35 weeks pregnant now, there was something wrong on my urine, and the doctor advised me to take cephalexin for my urine problem. I know the doctor knows best, but is there anyone here take the same pill and had a urine problem during pregnancy? Can this tablet affect my baby? Thanks c",)

Different drugs are in different classes and your doctor would have checked that before prescribing it to you. There are lots of drugs that are okay to take when you are pregnant. I had strep throat when I was pregnant with my frist and had to take an antibiotic and he is fine. If your doctor prescribed it then I wouldn't worry.

Category B
Most antibiotics are Category B, which means that there is no known association with birth defects or other pregnancy-related complication and the drug is probably safe. These include:

Amoxicillin
Ampicillin
Augmentin (amoxicillin-clavulanate)
Dicloxicillin
Macrobid (nitrofurantoin)
Flagyl (metronidazole) (although there is some controversy about taking it by mouth in the first trimester)
Cephalosporins including: Keflex (cephalexin), Ceclor (cefaclor), Duricef (cefadroxil)
Cleocin (clindamycin)
Erythromycin (all forms)
Zithromax (azithromycin)
Sulfa drugs (until near term)
Famvir (famciclovir)
Zovirax (acyclovir)
Valtrex (valacyclovir)
Clotrimazole-vaginal (Mycelex, Lotrimin

Can Cephalexin help me get pregnant?

I have been trying to pregnant for a few years now. So today I went to my doctor to get some help. He told me I have a bad infection in my fallopian tubes. So he put me on Cephalexin to clean everything out. He told me this will help me get pregnant. Has this happend to anyone?

Cephalex is an antibiotic.
If you do infact have an infection,it should clear it up.
It does not however make you more fertile.
Its just gonna clean up the infection,and help things to run smoothly again :0)

My wife is 12 weeks pregnant and has developed strep throat. how many mg's of cephalexin can she take?

I am just not sure if she can take the full 500 mg tablets that she has left over from when she was last sick.

Are you freakin' kidding me? You should NEVER take antibiotic that you have "left over" because you should never HAVE antibiotic "left over." They tell you to take all 10 days, and they mean it.

And the fact that she's pregnant just makes this question all the more crazy. How do you know she has strep? Obviously she hasn't seen a doctor.

So, you may or may not be giving your wife a drug that may or may not help her. And you don't have enough of it, if it's "left over." And you're not sure if she can take it while she's pregnant... and neither do we.

Go see a doctor. Have a throat culture done. Follow the doctor's instructions for treatment. Don't rely on Yahoo! Answers for things like this. Even if someone claims to be a doctor and says "sure, she can take it," you don't know if they're REALLY a doctor.

Good Grief!!

Possibly pregnant, is cephalexin safe to take?

I am on cephalexin (generic for Keflex) for a UTI. I am also breastfeeding my 4 month old baby and the doctor told me this antibiotic is safe to take while breastfeeding. I know exactly when I received the UTI and without too much information, my hubby and I have been using condoms since I'm nursing and don't want to take bc pills, and the condom was "lost" afterwards. We found it and needless to say, it definitely didn't do its job, ha. Anyway, this all happened on the 15th of this month, and because of what happened there is a possibility that I could have gotten pregnant. So my question is...if I did get prego, I would be one week pregnant right now while taking this antibiotic...would this cause any harm? Thanks

yes. i took it while pregnant and while nursing, its one of the safe ones to take while pregnant and nursing. good luck!

Can You Take Cephalexin While Pregnant?

Cephaalexin or Keflex is an antibiotic and caution is recommended for pregnant and nursing mothers. You need to check this with your physician. If you are self medicating then the answer is defnitely no, might be the wrong drug anyway.

does takin cephalexin 500mg 4 times a day and pregnant bad for the baby?

thats like 2000mg of antibiotic is that bad for my baby i have to take it for 10 dayz

Does the MD that prescribed the Cephalexin know that you are pregnant?
--If not, you need to immediately (not 5 minutes from now, not an hour from now and definitely not tomorrow, but NOW!) call either the prescribing MD or your OB and let them know of your condition.
--If your MD does know that you are pregnant....it is a class B drug for pregnancy, that means that in mice and rat studies (yes, you read right, mice and rats...no humans used in these studies), no harm came to any of the offspring of the animals that were being fed the drug. With that in mind, the MD is probably thinking that the infection (you don't say what kind of infection you have) that the antibiotic is being used to fight is of greater risk to you and/or the baby than the risk of taking this drug.
As for the dosage, the higher end of the dosing is twice what you are taking, so, the dosage isn't all that high.

O.k., I realize that it's the weekend, you can try to contact your MD or OB. If they don't have weekend hours (don't laugh, I have seen them!) most doc's also have a answering service, leave a message with them. If you can't get a hold of the doc, try calling your pharmacist(this may be the quickest & easiest during the weekend) or the ER (please call the ER AFTER you have exhausted all routes of docs or pharmacists, most ERs are swamped these days)

You have every right to question whether or not this drug is good/bad for you and your baby, please, don't let it slide.

I am 34 1/2 weeks pregnant and I have an abscess on my wisdom tooth, what kind of antibiotic would they give?

I am on cephalexin for a bladder infection, will that help?

original stuff/for all that does is knumb the nerve around tour tooth. nothing to worry about.

Has anyone ever taken this for a Uti while Pregnant?

well im 26weeks 4days pregnant and my doctor gave me Cephalexin 500mg i have to take it 4times a day for a UTI i only have to take it for a week but i was just wondering has anyone else ever taken this?

I took Cephalexin 500mg when I was 39 weeks along. My doctor told me it can have slight affects on the fetus but a UTI could have greater side affects to you and your fetus if left untreated. It is definitely better to take it earlier in pregnancy than later though. I was told that after 38 weeks it will have greater effect on a fetus and is not usually recommended, but then again so do most medicines as the fetus absorbs more in the final weeks. You'll be fine though, I took it late and had absolutely no problems. Everything cleared up just in time for my little one to come.