Investigators: Aarti Saiganesh, Amy Baker, Christine Everest, Joe Kado, Jonathan Carapetis, Nelly Newall, Rebecca Trowman, Robert Hand, Rosemary Wyber
External collaborators: Kevin Batty (Curtin University of Technology), Robert Henderson (Department of Health WA), Sam Salman (University of Western Australia)
Benzathine penicillin G (BPG) has been in use since the 1950s for treatment of skin infections, bacterial pharyngitis, syphilis and prevention of recurrent episodes of acute rheumatic fever (ARF). Current guidelines recommend BPG every 4 weeks for a minimum of 10 years to prevent the progression to rheumatic heart disease (RHD).
ARF and RHD predominantly affect children and young adults in resource-limited settings. Aboriginal and Torres Strait Islanders in Australia, and Maori and Pacific Islander populations in New Zealand experience high prevalence of ARF/RHD, despite low rates occurring in other Australian and New Zealander populations. RHD affects an estimated 33.4 million people worldwide, resulting in the death of approximately 319,400 people each year.
BPG is administered by deep intramuscular injection in the gluteal muscle, which is a painful injection. The pain associated with BPG injections is often cited as a reason for decreased adherence to the recommended schedule of secondary prophylaxis injections.
Numerous studies have suggested that intramuscular injections may not always be delivered as intended, as a thick layer of gluteal fat can prevent accurate delivery; in these cases, the injection is in fact delivered into the subcutaneous tissue. This occurs most often when administering injections to women, due to variability in fat distribution as compared to males. It is also not clear if the subcutaneous route of administration causes any more pain than the recommended intramuscular route.
Healthy male participants aged 18-65 meeting all the inclusion criteria and none of the exclusion criteria will receive two injections of BPG administered over 12 weeks.
The results of this trial will assist in:
- Determining if the route of administration of BPG has significant impact on pharmacokinetic properties of the medication.
- Ability to guide clinicians as to whether benzathine penicillin G should be delivered to an IM or SQ site, or either.
- Better understanding whether there is a difference in injection related pain between IM and SQ injections.
- Determining if a future reformulated long-acting penicillin should be delivered preferentially at an intramuscular or subcutaneous site.