Preventing bone loss with inhaled steroids
A I am unaware of any useful trials that compare three versus five days. Instead, a plethora of studies using differing antibiotics attempted to define the optimal treatment length. Three days seems optimal, with better compliance and potentially fewer side-effects, and an efficacy comparable to seven-day regimens. Generally, the less potent the antibiotic, the longer the therapy has to be.
With frequency, dysuria and urgency (in women unlikely to have occult pyelonephritis) empirical short courses of either three or five days of trimethoprim are reasonable.
Recurrence of symptoms makes culture mandatory to exclude resistance, and chlamydia if sexually active.
Short course therapy is not indicated for men, or if underlying renal tract abnormalities, previous short course failures, or diabetes mellitus.
Despite some success with single dose or one day's therapy (3g stat oral amoxicillin, two doses of co-trimoxazole, or 400mg of trimethoprim) several reviewers agreed three days' treatment was better than one at standard doses, even with the fluoroquinolones.
Recurrence due to coliform resistance is most likely with amoxicillin, limiting its use.
Most GPs and microbiologists would concur with SMAC. Ultimately the choice is up to the clinician; three days of a potent antibiotic may be more effective than even 10 days of a less potent one.
Marina Morgan is
consultant microbiologist at
Royal Devon and Exeter Hospital