Staphylococcus aureus is a common bacterium that often causes infections in humans. Methicillin-sensitive Staphylococcus aureus (MSSA) is a strain that is usually susceptible to antibiotics. Recent research suggests that using two antibiotics to treat MSSA bacteraemia, called SAFO, may not be advantageous. In this article, we will explore the findings of this study and what it means for healthcare professionals treating patients with MSSA infections. This article will provide the latest news for doctors, nurses, and pharmacists in the field of pharmacy.
The SAFO trial analysed the effectiveness of cloxacillin combined with fosfomycin in achieving treatment success in hospitalized patients with methicillin-susceptible Staphylococcus aureus (MSSA) bacteraemia. The results of the trial were presented at the ECCMID 2023 and showed that using cloxacillin alone was as effective in achieving treatment success as the cloxacillin plus fosfomycin combination.
The primary endpoint of the study was to attain treatment success at day 7, and the results showed that 79.8 percent of patients who received cloxacillin plus fosfomycin achieved treatment success, while 74.5 percent of patients who received cloxacillin alone achieved the same. Treatment success was defined as a composite of patient survival, stable or improved quick-Sequential Organ Failure Assessment score, absence of fever, and negative blood cultures for MSSA. The study showed a difference of 5.3 percent in treatment success rates between the two groups, which was not statistically significant.
Dr Sara Grillo, the lead study investigator, reported that the findings of the SAFO trial were consistent with other randomized clinical trials that evaluated antibiotic combinations and found no improvement in treatment outcomes in patients with MSSA bacteraemia.
The trial was conducted at 19 Spanish hospitals and involved 214 adult inpatients with MSSA bacteraemia. The most common cause of bacteremia was intravascular catheter infection. None of the patients had liver cirrhosis, NYHA Class III-IV heart failure, allergy to beta-lactams or fosfomycin, prosthetic endocarditis, or SARS-CoV-2 infection. Of the patients, 110 received intravenous cloxacillin, while 104 received cloxacillin in combination with intravenous fosfomycin. Add-on fosfomycin was given within the first 7 days of treatment, and sequential antibiotic therapy was at the discretion of the physicians.
Grillo noted that the trial was terminated before reaching the planned enrolment of 366 patients because there was no benefit of combination antibiotic therapy on treatment success. However, the antibiotic combination resulted in a significantly lower rate of persistent bacteraemia at day 3 compared to cloxacillin alone.
Other secondary endpoints, including all-cause mortality, persistent bacteraemia, relapsing bacteraemia, complicated bacteraemia, and the emergence of fosfomycin-resistant strains, were similar in the two treatment groups. In terms of safety, cloxacillin plus fosfomycin was associated with a slightly higher rate of adverse events that led to discontinuation of therapy as compared to cloxacillin alone.
The current standard of treatment for MSSA bacteraemia is antistaphylococcal beta-lactam monotherapy. However, since mortality rates are still high, there has been an increasing interest in finding new treatment combinations that could improve outcomes in S aureus bacteraemia. Grillo called for additional trials to evaluate other treatment strategies for MSSA bacteraemia in light of the findings of the SAFO study.
In conclusion, SAFO’s study on the use of dual antibiotics to treat MSSA bacteraemia provides valuable insight for healthcare providers. While it may seem advantageous to use multiple antibiotics in treating infections, this study shows that it may not necessarily be beneficial in all cases. The findings suggest that medical professionals should carefully consider the potential risks and benefits of dual antibiotic treatments for each individual patient, to ensure optimal outcomes. As medical research continues to evolve, we will undoubtedly discover more effective ways to treat and cure infectious diseases. Stay tuned to Pharmacy for the latest news and updates on healthcare innovations and breakthroughs.
