From the Guidelines
Cephalexin is safe to use during the third trimester of pregnancy, as evidenced by recent clinical guidelines 1.
Key Points to Consider
- The use of cephalexin in pregnant patients with hidradenitis suppurativa (HS) is suggested due to its safety profile, with a conditional recommendation and moderate quality of evidence 1.
- Cephalexin is classified as an FDA pregnancy category B drug, indicating that animal studies have not shown risk to the fetus and there are no adequate studies in pregnant women showing adverse effects.
- The typical adult dosage of cephalexin is 250-500 mg taken orally every 6 hours, or 500-1000 mg every 12 hours, depending on the severity of infection, with treatment usually lasting 7-14 days.
- Potential side effects of cephalexin include diarrhea, nausea, and allergic reactions, and patients with a history of severe penicillin allergy should use caution due to approximately 10% cross-reactivity between penicillins and cephalosporins.
- Cephalexin works by inhibiting bacterial cell wall synthesis and has not been associated with significant fetal harm when used in late pregnancy, making it a reasonable antibiotic choice when treatment is necessary during the third trimester 1.
Important Considerations
- It is essential to complete the full course of antibiotics even if symptoms improve to ensure effective treatment and prevent antibiotic resistance.
- Cephalexin is commonly prescribed for urinary tract infections, respiratory infections, and skin infections during pregnancy when the benefits outweigh potential risks.
- Recent clinical guidelines suggest that cephalexin, azithromycin, and clindamycin are safe in pregnancy, with no adverse effects reported 1.
From the FDA Drug Label
Pregnancy Teratogenic Effects Pregnancy category B Reproduction studies have been performed on mice and rats using oral doses of cephalexin monohydrate 0.6 and 1. 5 times the maximum daily human dose (66 mg/kg/day) based upon mg/m2, and have revealed no harm to the fetus. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed
Cephalexin use in the third trimester: The FDA drug label indicates that cephalexin is classified as a Pregnancy Category B drug, which means that reproduction studies in animals have not shown a risk to the fetus, but there are no adequate and well-controlled studies in pregnant women. Therefore, cephalexin should be used during pregnancy, including the third trimester, only if clearly needed 2.
From the Research
Cephalexin Safety in Third Trimester
- Cephalexin is a cephalosporin antibiotic that has been studied for its safety during pregnancy, including the third trimester 3.
- A study on the kinetics of cephapirin and cephalexin in pregnancy found that both antibiotics crossed the placenta barrier and reached levels in the amniotic fluid and cord serum adequate for the in vitro inhibition of pathogens involved in materno-foetal infections 3.
- Another study compared the effectiveness of amoxicillin-clavulanic acid and cephalexin in treating bacteriuria during pregnancy, and found that cephalexin was effective and safe, with no significant difference in cure rates or side effects between the two groups 4.
- While there is limited direct evidence on the safety of cephalexin specifically in the third trimester, beta-lactam antibiotics, which include cephalosporins like cephalexin, are generally considered safe during pregnancy, including the third trimester 5, 6.
- It is essential to note that the safety of any medication during pregnancy should be evaluated on a case-by-case basis, considering the potential benefits and risks, and under the guidance of a healthcare provider.
Key Findings
- Cephalexin crosses the placenta barrier and reaches adequate levels in the amniotic fluid and cord serum 3.
- Cephalexin is effective in treating bacteriuria during pregnancy, with no significant difference in cure rates or side effects compared to amoxicillin-clavulanic acid 4.
- Beta-lactam antibiotics, including cephalosporins like cephalexin, are generally considered safe during pregnancy, including the third trimester 5, 6.