Comparison of trimethoprim-sulfamethoxazole versus minocycline monotherapy for treatment of Stenotrophomonas maltophilia pneumonia

OBJECTIVE: To compare the rate of clinical cure and adverse effects in patients receiving definitive treatment with trimethoprim-sulfamethoxazole versus minocycline monotherapy for Stenotrophomonas maltophilia pneumonia. METHODS: A single-centre, retrospective cohort study of patients with S. maltophilia pneumonia admitted 1 March 2018-30 September 2023 was conducted comparing treatment with trimethoprim-sulfamethoxazole versus minocycline monotherapy. The primary outcome was the rate of clinical cure, defined as meeting two of the three prespecified criteria for a period of 48 hours while on definitive therapy: normalization of white blood cell count, absence of fever and hypothermia and decreased oxygen support. Secondary outcomes evaluated included time to clinical cure, infection-related and in-hospital mortality, pneumonia recurrence and incidence of adverse effects, which was a composite of acute kidney injury (AKI), hyperkalaemia and thrombocytopenia. RESULTS: Of 93 patients included, 48 received trimethoprim-sulfamethoxazole and 45 received minocycline. There was no difference in the primary outcome of clinical cure between the trimethoprim-sulfamethoxazole and minocycline groups (72.9% versus 66.7%, P = 0.51). S. maltophilia pneumonia recurrence was more common in the minocycline group compared to the trimethoprim-sulfamethoxazole group (35.6% versus 10.4%, P = 0.006). In-hospital mortality was higher in the trimethoprim-sulfamethoxazole group although there was no difference in infection-related in-hospital mortality (6.3% versus 2.3%, P = 0.62). The incidence of AKI, hyperkalaemia and thrombocytopenia did not differ between groups. CONCLUSION: There was no difference in clinical cure rate for S. maltophilia pneumonia treatment between trimethoprim-sulfamethoxazole and minocycline monotherapy although higher rates of recurrent pneumonia were observed in patients treated with minocycline. Rates of adverse effects were similar between groups.