Empirical Antibiotic Treatment of Acute Cystitis

The Therapeutic Guidelines: Antibiotic has recently had a major update. One of the more significant changes relates to the empirical antibiotic treatment of acute cystitis. The updated recommendations are shown in Table 1.

Table 1. Empiric antibiotic therapy recommendations from the Therapeutic Guidelines

* Cefalexin is considered an alternative option if the other recommended agents cannot be used for empirical therapy.

Trimethoprim is no longer recommended as a first-line agent due to rising rates of resistance among Escherichia coli. The most recent AURA report (Australian report on antimicrobial use and resistance in human health) states that 22.6% of urinary E. coli isolates were resistant to trimethoprim in 2021. In contrast, only 0.9% were resistant to nitrofurantoin.

Nitrofurantoin is now the first-line agent in most cases. The typical adult dose is 100 mg six-hourly for five days in women and seven days in men. Doses should be administered with food or milk to reduce nausea and vomiting.

Fosfomycin is now the second-line choice for non-pregnant adult females. It is administered orally as a 3 g single dose. Fosfomycin is available in single-dose sachets that are mixed with water immediately before use. Doses should be taken on an empty stomach, preferably before bedtime and after emptying the bladder. At this time, fosfomycin is not subsidised on the Pharmaceutical Benefits Scheme (PBS).

For a full list of new and updated topics, please refer to the summary provided by the Therapeutic Guidelines.