Is Clarithromycin safe during pregnancy?

From the Guidelines

Clarithromycin Safety During Pregnancy

Clarithromycin is probably safe for use during pregnancy, particularly for the treatment of bacterial infections. The recommended dose is 250-500 mg orally twice daily for 7-14 days, depending on the specific infection being treated 1. However, due to the potential risk of hypertrophic pyloric stenosis in infants exposed to macrolides during the first 13 days of breastfeeding, clarithromycin should be used with caution during the first trimester, and alternative antibiotics should be considered if possible 1.

• Key points to consider:
  • Clarithromycin has been shown to produce adverse pregnancy outcomes in experimental animals, but human data suggest low risk 1.
  • An epidemiological study suggests a very low risk of hypertrophic pyloric stenosis in infants exposed to macrolides during the first 13 days of breastfeeding 1.
  • Close monitoring of fetal development is recommended in cases where clarithromycin is deemed necessary 1.
• Alternative antibiotics, such as azithromycin, may be considered for use during pregnancy, particularly during the first trimester, due to their safer profile 1.

From the FDA Drug Label

1. 1 Pregnancy Risk Summary Based on findings from animal studies, clarithromycin is not recommended for use in pregnant women except in clinical circumstances where no alternative therapy is appropriate. If pregnancy occurs while taking clarithromycin, the patient should be apprised of the potential hazard to the fetus [see Warnings and Precautions (5. 7)]. Limited data from a small number of published human studies with clarithromycin use during pregnancy are insufficient to inform drug-associated risks of major birth defects, miscarriage, or adverse maternal or fetal outcomes In animal reproduction studies, administration of oral clarithromycin to pregnant mice, rats, rabbits, and monkeys during the period of organogenesis produced malformations in rats (cardiovascular anomalies) and mice (cleft palate) at clinically relevant doses based on body surface area comparison.

Clarithromycin is not recommended for use in pregnant women except in clinical circumstances where no alternative therapy is appropriate, due to potential hazards to the fetus, as evidenced by animal reproduction studies showing malformations and other adverse effects at clinically relevant doses 2.

From the Research

Safety of Clarithromycin During Pregnancy

• The safety of clarithromycin during pregnancy is a concern, with some studies suggesting an increased risk of major malformations and cardiovascular malformations 3.
• A study published in 2020 found that macrolide prescribing during the first trimester was associated with an increased risk of any major malformation and specifically cardiovascular malformations compared with penicillin antibiotics 3.
• Another study published in 2013 found no meaningful associations between the risks of congenital heart defects, pyloric stenosis, and other common malformations in relation to use of macrolides in pregnancy, including clarithromycin 4.
• However, the 2020 study suggests that macrolides, including clarithromycin, should be used with caution during pregnancy and alternative antibiotics should be prescribed if feasible 3.

Studies on Clarithromycin

• Several studies have investigated the efficacy and safety of clarithromycin in treating respiratory tract infections, but few have focused specifically on its use during pregnancy 5, 6, 7.
• A study published in 1993 compared clarithromycin with cefixime in treating lower respiratory tract infections and found that clarithromycin was effective and well-tolerated 5.
• Another study published in 2003 evaluated the clinical efficacy of oral clarithromycin monotherapy in patients with mild or moderate community-acquired pneumonia and found that it was effective and safe 6.
• A review of clarithromycin extended-release tablets published in 2003 found that it was effective and well-tolerated in treating respiratory tract infections, including acute exacerbations of chronic bronchitis and community-acquired pneumonia 7.

Pregnancy Considerations

• The use of clarithromycin during pregnancy should be carefully considered, taking into account the potential risks and benefits 3, 4.
• Pregnant women should consult their healthcare provider before taking clarithromycin or any other medication 3, 4.
• Alternative antibiotics may be prescribed if feasible, especially during the first trimester of pregnancy 3.