Phase 1 Study of the Pharmacokinetics of Amoxicillin in Pregnancy

A Rational Approach to the Identification of New Treatment Options to Prevent Congenital Syphilis: Phase 1 Study of the Pharmacokinetics of Amoxicillin in Pregnancy

The study design is a prospective phase I pharmacokinetic study focused on dosing of 500 mg oral amoxicillin administration in pregnant women in the 2nd and 3rd trimester.

Study Overview

• Status: Completed
• Conditions: Pregnancy Related
• Intervention / Treatment: Drug: Amoxicillin

Detailed Description

Twenty adult pregnant women in good health who are admitted for preterm premature rupture of membranes (24-34 weeks gestational age) will be enrolled in this intensive pharmacokinetic study. Basic information will be collected from the medical record including age, weight, height, pregnancy dating, medications, and allergies.

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Alabama
    • Birmingham, Alabama, United States, 35294
      • UAB

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 50 years (Child, Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Pregnant, engaged in prenatal care with a medical provider (at least one visit)
2. Estimated gestational age 24-34 weeks
3. Able to provide informed consent
4. English speaking

Exclusion Criteria:

1. Receipt of amoxicillin within the past 7 days. (Routine GBS prophylaxis with ampicillin or other antibiotic and routine surgical prophylaxis prior to cesarean with cephalexin and azithromycin 500 mg IV is allowed).
2. Known hypersensitivity or intolerance of amoxicillin, penicillin, other beta lactam or cephalosporin antibiotics.
3. Known renal impairment (serum creatinine ≥1.2 mg/dL).
4. Active concomitant medications known to interact with amoxicillin: allopurinol, methotrexate, mycophenolate, immune checkpoint inhibitors (ie. pembrolizumab), tetracyclines (ie. doxycycline), vitamin K antagonists (ie. warfarin), aminoglycosides (ie. gentamicin).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Amox 500 mg; Amoxicillin 500 mg PO	Drug: Amoxicillin; medication administration; Other Names: Probenecid

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of Amoxicillin Level in Plasma during Pregnancy	quantitative drug level in blood	0, 1, 2, 3, 4, 6, 8 hours after medication administration
Amoxicillin Level in Cord Blood	quantitative drug level in cord blood to calculate transplacental transfer rate for amoxicillin	at delivery
Change of Amoxicillin Level in Plasma in the Postpartum state	quantitative drug levels in blood to compare to pregnancy state values	0, 1, 2, 3, 4, 6, 8 hours after medication administration

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
additional pharmacologic measures	1. Maximum concentration (Cmax) in maternal serum.	1-8 hours after administration
Additional pharmacologic measure	time to maximum concentration (tmax) in maternal serum	1-8 hours after administration

Collaborators and Investigators

• Sponsor: University of Alabama at Birmingham
• Investigators: Principal Investigator: Jodie Dionne, MD, University of Alabama at Birmingham

Study record dates

Study Major Dates

• Study Start (Actual): August 29, 2023
• Primary Completion (Actual): January 16, 2025
• Study Completion (Actual): June 30, 2025

Study Registration Dates

• First Submitted: March 14, 2022
• First Submitted That Met QC Criteria: March 24, 2022
• First Posted (Actual): April 4, 2022

Study Record Updates

• Last Update Posted (Estimated): December 17, 2025
• Last Update Submitted That Met QC Criteria: December 10, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: pharmacokinetics; amoxicillin
• Additional Relevant MeSH Terms: Infections; Communicable Diseases; Sexually Transmitted Diseases; Infant, Newborn, Diseases; Gram-Negative Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Sexually Transmitted Diseases, Bacterial; Spirochaetales Infections; Treponemal Infections; Urogenital Diseases; Genital Diseases; Syphilis; Syphilis, Congenital; Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Amides; Penicillin G; beta-Lactams; Lactams; Sulfonamides; Sulfones; Ampicillin; Penicillins; Amoxicillin; Probenecid
• Other Study ID Numbers: IRB-300008691; UAB (Other Identifier: UAB)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No