{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T21:23:00Z","timestamp":1787865780561,"version":"build-2784847793"},"reference-count":41,"publisher":"Oxford University Press (OUP)","issue":"6","license":[{"start":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T00:00:00Z","timestamp":1780531200000},"content-version":"vor","delay-in-days":3,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"name":"UAB Center for Research in Women\u2019s Health"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,6,2]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>This open-label study compared single-dose oral amoxicillin pharmacokinetics during pregnancy and postpartum relative to the established in vivo minimum inhibitory concentration (MIC) for Treponema pallidum (0.42\u2005mcg\/mL).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Pregnant women in good health at 24\u201334\u2005weeks gestational age prescribed amoxicillin for preterm premature rupture of membranes were eligible. A 500-mg oral dose was administered at enrollment and 6\u2005weeks postpartum. Blood was collected at time 0 (predose) and at 1, 2, 3, 4, 6, and 8 hours postdose; venous cord blood was obtained at delivery. Amoxicillin concentrations were quantified with high-performance liquid chromatography with tandem mass spectrometry. Noncompartmental and population pharmacokinetic analyses were used to summarize parameters and estimate time above MIC (%T &amp;gt; MIC) and time of free drug concentrations &amp;gt;70%MIC (\u0192T &amp;gt; 70%MIC), for 500, 750, 875, and 1000\u2005mg dosed every 8 or 12\u2005hours.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Participants (n = 13) had a median age of 29\u2005years and gestational age of 31\u2005weeks. Three women (23%) returned for postpartum visits. Amoxicillin concentrations were reduced during pregnancy compared with postpartum: the median 8-hour area under the curve was 14 vs 22.2\u2005mgxh\/L (P = .007), and oral clearance was 34 vs 22\u2005L\/h (P = .03). The amoxicillin half-life was 1.3\u2005hours. Simulated 12-hour dosing produced lower %\u0192T &amp;gt; MIC results relative to the 8-hour dosing regimens.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Oral amoxicillin dosed every 8\u2005hours during pregnancy is needed to maintain concentrations above the syphilis MIC threshold. Modeling suggests that 750\u2005mg every 8\u2005hours maintains adequate exposure during pregnancy and should be evaluated in future trials.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ofid\/ofag336","type":"journal-article","created":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T11:34:18Z","timestamp":1780400058000},"source":"Crossref","is-referenced-by-count":1,"title":["Pharmacokinetics of Oral Amoxicillin for the Treatment of Syphilis in Pregnancy"],"prefix":"10.1093","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3625-5174","authenticated-orcid":false,"given":"Jodie A","family":"Dionne","sequence":"first","affiliation":[{"name":"Division of Infectious Diseases, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akila","family":"Subramaniam","sequence":"additional","affiliation":[{"name":"Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Alabama at Birmingham , Birmingham, Alabama ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mauricio","family":"Kahn","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yumo","family":"Xue","sequence":"additional","affiliation":[{"name":"Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Alabama at Birmingham , Birmingham, Alabama ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3512-3495","authenticated-orcid":false,"given":"Kevin J","family":"Ryan","sequence":"additional","affiliation":[{"name":"Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Alabama at Birmingham , Birmingham, Alabama ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Edward P","family":"Acosta","sequence":"additional","affiliation":[{"name":"Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Alabama at Birmingham , Birmingham, Alabama ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,6,4]]},"reference":[{"key":"2026063011222381800_ofag336-B1","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1097\/OLQ.0000000000002113","article-title":"Summary of the National Institute of Allergy and Infectious Diseases workshop on alternative therapies to penicillin for the treatment of syphilis","volume":"52","author":"Cato","year":"2025","journal-title":"Sex Transm Dis"},{"key":"2026063011222381800_ofag336-B2","author":"Centers for Disease Control and Prevention"},{"key":"2026063011222381800_ofag336-B3","author":"Centers for Disease Control and Prevention"},{"key":"2026063011222381800_ofag336-B4","author":"Centers for Disease Control and Prevention"},{"key":"2026063011222381800_ofag336-B5","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1128\/AAC.32.1.68","article-title":"In vitro culture system to determine MICs and MBCs of antimicrobial agents against Treponema pallidum subsp. pallidum (Nichols strain)","volume":"32","author":"Norris","year":"1988","journal-title":"Antimicrob Agents Chemother"},{"key":"2026063011222381800_ofag336-B6","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1056\/NEJM199707313370504","article-title":"A randomized trial of enhanced therapy for early syphilis in patients with and without human immunodeficiency virus infection. 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