Add-on fluoroquinolone of no benefit in Japanese spotted fever

In the treatment of patients with Japanese spotted fever (JSF), the addition of fluoroquinolone antimicrobials does not appear to provide any benefit beyond that obtained with tetracyclines, as shown in a study.

The study used data from the Japanese Diagnosis Procedure Combination inpatient database and included 1,060 hospitalized patients (median age 71 years, 47.5 percent male) diagnosed with JSF. Of these, 434 (41 percent) received fluoroquinolone plus tetracycline on the day of admission while 626 (59 percent) were administered tetracycline alone.

Researchers applied inverse probability of treatment weighting to compare the primary outcome of in-hospital mortality between the two patient groups. They also evaluated in-hospital complications, total hospitalization costs, and length of hospital stay as secondary outcomes.

The median duration of tetracycline in all 1,060 patients was 8 days, whereas the median duration of quinolone was 6 days. Patients in the fluoroquinolone plus tetracycline group were more likely to have severe dependent physical function at admission, clear consciousness at admission, and higher Charlson comorbidity index score.

Results of inverse probability of treatment weighting analyses revealed that the two treatment groups had similar in-hospital mortality rate (2.0 percent vs 1.0 percent; odds ratio, 1.94), in-hospital complication rate (8.4 percent vs 6.3 percent; odds ratio, 1.36), total hospitalization costs, and length of hospital stay.

The findings indicate that clinicians have to be cautious regarding the administration of fluoroquinolone and tetracycline antimicrobials concomitantly in routine practice.