Can pregnant patients receive Ceftriaxone (Ceftriaxone) or Metronidazole (Flagyl)?

From the Guidelines

Pregnant patients can receive Ceftriaxone or Metronidazole when clearly needed to treat infections, as the benefits of treatment typically outweigh potential risks. According to the most recent and highest quality study, [ 1 ], Ceftriaxone is classified as FDA pregnancy category B, meaning animal studies have not shown risk to the fetus and there are no adequate studies in pregnant women. Metronidazole is also classified as FDA pregnancy category B, and while older concerns existed about first trimester use, more recent data supports its safety throughout pregnancy when clinically indicated.

Key Considerations

• The benefits of treating serious infections with Ceftriaxone or Metronidazole typically outweigh potential risks in pregnant patients.
• Dosing for pregnant women is generally the same as for non-pregnant adults: Ceftriaxone is typically given at 1-2g daily, while Metronidazole dosing ranges from 500mg three times daily to 2g as a single dose.
• As with any medication during pregnancy, these antibiotics should be used at the lowest effective dose for the shortest duration necessary to treat the infection.
• The study [ 1 ] suggests that Metronidazole can be used during pregnancy and lactation if there are no other safer alternatives, and Ceftriaxone is considered possibly safe during pregnancy.

Safety and Efficacy

• Ceftriaxone and Metronidazole have been shown to be safe and effective in treating various infections in pregnant patients, with the most recent study [ 1 ] providing guidance on their use.
• The study [ 1 ] also supports the use of Ceftriaxone as a second-line therapy for treating Bartonella infections in pregnant women.
• However, it is essential to consider the potential risks and benefits of each medication and to use them at the lowest effective dose for the shortest duration necessary to treat the infection.

Clinical Guidance

• Pregnant patients should be closely monitored while receiving Ceftriaxone or Metronidazole, and the medications should be used only when clearly needed to treat infections.
• The study [ 1 ] highlights the importance of treating gonococcal infection in pregnant women to prevent neonatal gonococcal disease, and Ceftriaxone is a recommended treatment option.
• As with any medication, it is crucial to weigh the potential benefits and risks of Ceftriaxone and Metronidazole in pregnant patients and to use them judiciously.

From the FDA Drug Label

Metronidazole crosses the placental barrier and enters the fetal circulation rapidly. Reproduction studies have been performed in rats at doses up to five times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to metronidazole. No fetotoxicity was observed when metronidazole was administered orally to pregnant mice at 20 mg/kg/day approximately one and a half times the most frequently recommended human dose (750 mg/day) based on mg/kg body weight; However in a single small study where the drug was administered intraperitoneally, some intrauterine deaths were observed The relationship of these findings to the drug is unknown. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, and because metronidazole is a carcinogen in rodents, this drug should be used during pregnancy only if clearly needed

• Metronidazole: The FDA drug label indicates that metronidazole can be used during pregnancy if clearly needed, but due to potential risks, its use should be carefully evaluated, especially during the first trimester 2 3.
• Ceftriaxone: The FDA drug label does not answer the question.

From the Research

Treatment of Pregnant Patients with Ceftriaxone or Metronidazole

• Ceftriaxone can be used to treat pregnant patients with certain infections, such as gonorrhea, chlamydial infection, and syphilis 4, 5.
• The recommended treatment for gonorrhea is intramuscular ceftriaxone (125 or 250 mg) or oral cefixime 400 mg 4.
• Ceftriaxone has been shown to be effective in treating early syphilis in pregnancy, with a dosage of 250 mg given intramuscularly once daily for 7 and 10 days for primary and secondary syphilis, respectively 5.
• Metronidazole can be used to treat pregnant patients with Trichomonas vaginalis, with a recommended dosage of 500 mg twice daily for 7 days 4.
• Metronidazole is also used to treat bacterial vaginosis in pregnant patients, with a recommended dosage of 1 g/day for 5 days 4.
• Studies have shown that ceftriaxone has a good safety record during pregnancy, with no evidence of accumulation or adverse effects on the fetus 6, 7, 8.
• The pharmacokinetics of ceftriaxone during pregnancy have been studied, and the results suggest that the dosage schedule of ceftriaxone (2-g infusion per day) requires no particular adjustment during the third trimester of pregnancy 6, 7.