Description of the condition
Urinary tract infection (UTI) is the most common form of bacterial infection in women, most of which are uncomplicated (Foxman 2003). UTIs are considered uncomplicated in the absence of urinary tract abnormalities, obstruction or resistant pathogens, pregnancy, immunocompromised state, or acute pyelonephritis. The term 'uncomplicated' is not applied to UTIs in adult men.
Standard conventional management of suspected UTI is to confirm presence of either bacteria or white cells in the urine, and treat with antibiotics. However, studies have challenged this approach. Whatever the role of antibiotics, women often seek relief from the symptoms of UTI until either the infection is cleared with antibiotics or resolves spontaneously. Uncomplicated UTI often spontaneously remit without antibiotics: a recent pilot randomised controlled trial (RCT) found that symptomatic treatment for uncomplicated UTI was non-inferior to antimicrobial therapy (Bleidorn 2010). Nonetheless, an earlier study also found that women with culture-negative symptoms of UTI respond to antibiotics (Richards 2005).
Description of the intervention
Several clinical guidelines for UTI treatment advise first-line use of antibiotics (ACOG 2008; Grabe 2010; IDSA/ESMI 2011). However, until infection has cleared (due to either antimicrobial therapy or spontaneous remit), symptoms may be troublesome. The use of urinary alkalisers for the symptomatic treatment of uncomplicated UTI is very common in some countries. For example, more than one million units of urinary alkalisers are sold in Australia annually; many of these are used specifically for UTIs and acute culture-negative cystitis. Use of urinary alkalisers for the symptomatic treatment of UTI and cystitis appear in MIMS Australia and other national formularies (eMC 2013; MIMS 2013). Use is also widely promoted by primary healthcare practitioners. Literature supporting benefits from use of these agents is sparse; some guidelines specifically state that they are not recommended (NICE 2009).
How the intervention might work
Urinary alkalisers primarily work to raise urine pH, which in theory, aids in the symptomatic treatment of dysuria. Dysuria and urinary frequency are the most common and bothersome symptoms of UTI and acute culture-negative cystitis (Munday 1990; Spooner 1984).
Urinary pathogens, such as Proteus mirabilis can also increase urinary pH and are associated with symptoms of dysuria and urinary frequency (Franz 1999); however, it has been suggested elsewhere that raising urine pH does not affect the sensation of dysuria (Brumfitt 1990).
Why it is important to do this review
Uncomplicated UTI is very common, and imposes significant financial burden. In the US, UTI is responsible for over seven million physician visits annually, and account for the use of approximately 15% of all community-prescribed antibiotics. The total annual estimated cost of antibiotics for UTI in the USA exceeds one billion USD (Foxman 2002; Mazzulli 2002). The advent of increasing numbers of drug resistant organisms means that avoidance of unnecessary antibiotics is important.
Urinary alkalisers are widely used globally for symptomatic relief of UTI and acute culture-negative cystitis. There is however a paucity of good evidence to support their use. There is also conflicting evidence surrounding urinary alkalinisation for antimicrobial eradication in UTI. Some studies show benefit of concomitant urinary alkalisers and antibiotic use, with reduced antibiotic MIC when urine is at alkaline pH. Other studies show that urine pH within the acidic range is favourable, as it can have a bactericidal effect (Burian 2012; Carlsson 2003; Zhanel 1991). Although we aim to focus on symptom relief in UTI, antimicrobial eradication may also be important, as prolonged positive urine culture may lead to a prolongation of symptoms. If we find insufficient evidence surrounding these agents, then this sets a research agenda.