Could late-latent syphilis be treated with a single subcutaneous infusion of long-acting penicillin?

Thel K. Hla; Sam Salman; Joseph Kado; Brioni R. Moore; Laurens Manning

doi:10.1071/SH24003

EDITORIAL

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Could late-latent syphilis be treated with a single subcutaneous infusion of long-acting penicillin?

Thel K. Hla

^A ^B ^C ^* , Sam Salman ^A ^B ^D , Joseph Kado ^A ^B , Brioni R. Moore ^A ^B ^E and Laurens Manning ^A ^B ^C

+ Author Affiliations

- Author Affiliations

^A Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Perth, WA, Australia.

^B Medical School, University of Western Australia, Perth, WA, Australia.

^C Department of Infectious Diseases, Fiona Stanley Hospital, Perth, WA, Australia.

^D Clinical Pharmacology and Toxicology Unit, PathWest, WA, Australia.

^E Curtin Medical School, Curtin University, Perth, WA, Australia.

^* Correspondence to: thel.hla@telethonkids.org.au

Handling Editor: Michael Marks

Sexual Health 21, SH24003 https://doi.org/10.1071/SH24003

Submitted: 18 January 2024 Accepted: 11 March 2024 Published: 26 March 2024

Abstract

Syphilis is an important global health threat and little has changed in its treatment since the mid-20th century. For late-latent or syphilis infection of unknown duration, the standard treatment of multiple intramuscular injections of benzathine penicillin G (BPG) are associated with significant pain and distress to clients and caregivers, negatively impacting on treatment completion. Based on pharmacokinetic modelling from a Phase I study of subcutaneous infusion of high dose BPG (SCIP), we present its feasibility, safety and tolerability for treatment of syphilis in a single infusion. SCIP leads to more sustained penicillin concentrations above the desired target with less reported pain and reduced clinic visits.

Keywords: antibiotics, benzathine penicillin G, late latent syphilis, population pharmacokinetics, subcutaneous penicillin, syphilis, syphilis of unknown duration, treatment of syphilis.

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