Persistence of penicillin G benzathine in pregnant group B streptococcus carriers

• Published in: Obstetrics and gynecology (New York. 1953) Vol. 90; no. 2; pp. 240 - 243
• Main Authors: Weeks, Jonathan W., Myers, Steven R., Lasher, Lisa, Goldsmith, Jane, Watkins, Christopher, Gall, Stanley A.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.08.1997; The American College of Obstetricians and Gynecologists; Elsevier Science
• Subjects: Adult; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Biological and medical sciences; Carrier State; Female; Fetal Blood - chemistry; Humans; Infant, Newborn; Medical sciences; Penicillin G Benzathine - administration & dosage; Penicillin G Benzathine - blood; Penicillin G Benzathine - therapeutic use; Penicillins - administration & dosage; Penicillins - blood; Penicillins - therapeutic use; Pharmacology. Drug treatments; Pregnancy; Pregnancy Complications, Infectious - drug therapy; Pregnancy Complications, Infectious - microbiology; Streptococcal Infections - drug therapy; Streptococcal Infections - prevention & control; Streptococcus agalactiae - drug effects; Streptococcus agalactiae - isolation & purification; Time Factors; Human; Concentration factor; Benzylpenicillin; Infection; Pregnancy; Penicillin derivatives; Streptococcaceae; Antibiotic; Chemotherapy; Treatment; Streptococcal infection; Streptococcus B; Bacteriosis; Bacteria; Micrococcales; Female; Serum; Antibacterial agent
• ISSN: 0029-7844; 1873-233X
• DOI: 10.1016/S0029-7844(97)00247-0

To determine if streptococcicidal levels of penicillin G benzathine can be detected in maternal serum 4 weeks after treatment with 4.8 million units. Thirty-seven pregnant women with positive group B streptococcus vaginal or urine cultures were each given 4.8 million units of penicillin G benzathine. Maternal blood samples were collected after injection and at delivery. Serum penicillin levels were measured by high-pressure liquid chromatography. Follow-up cultures were done when possible. None of the patients had serum penicillin levels below 0.20 μg/mL 30 days after treatment. Cord blood levels were approximately 50% lower than maternal levels. In all but three subjects, cord blood levels exceeded 0.06 μg/mL, the minimal inhibitory concentration for group B streptococcus. The three exceptions were patients who delivered more than 100 days after treatment. Group B streptococcus cultures were negative at the time of delivery in 72% of cases. None of the patients with positive cultures were moderately or heavily colonized. In pregnant women, penicillin G benzathine levels are high enough to inhibit the growth of group B streptococcus for more than 4 weeks after injection with 4.8 million units. Further studies are needed to evaluate whether this regimen can prevent neonatal colonization and invasive group B streptococcus disease.