We read with interest the letter by Mr Lance Gravatt in the December 16th 2016 issue of the Journal titled “Urinary alkalisers for cystitis—fact or fiction?”.1 While the fundamental message about the lack of evidence base for routine use of alkalisers for cystitis is reflected well in the letter, there are a few points that we wish to highlight.

Firstly, there are a few inaccuracies in the introductory statement of the letter where our study2 is referenced. The study setting was at Waitakere hospital in West Auckland and not Auckland City Hospital.
New cases of infection were identified over two separate 24 hour periods and not during a single day. There were 81 admissions where any infection was the primary or secondary reason for hospitalisation. Urinary tract infections (UTI) contributed to only 22% (n=18) of these cases. The letter mentions 81 UTIs instead.
The mean length of hospital stay was 5.5 and 12.5 days for medical and rehabilitation patients respectively, and not four days.
Furthermore, it is our view that this reference seems to be somewhat irrelevant to the topic of this letter, which focuses predominantly on outpatient treatment of uncomplicated cystitis.

Secondly, it is worth noting that the activity of certain antibiotics may be affected by changes in urinary pH. Examples include nitrofurantoin (a commonly used antibiotic for treatment of cystitis), which has maximal antibacterial activity in acidic urine, while aminoglycosides and co-trimoxazole demonstrate greater activity against common urinary pathogens with increasing pH.3

Thirdly, we like to draw the reader’s attention to increasing use of restricted antibiotics like pivmecillinam and fosfomycin in both hospital and community settings to treat extended spectrum beta-lactamase producing (ESBL) E.coli and klebsiella pneumoniae bacteria. Such antibiotics are not affected by urinary alkalisers, and are often used when other oral options are limited due to either resistance or drug intolerance issues. A retrospective review4 performed at North Shore Hospital between June 2014 and October 2015 revealed that 70 inpatients with uncomplicated ESBL UTIs (resistant also to nitrofurantoin and norfloxacin) were treated with either fosfomycin (n=42) or pivmecillinam (n=28), after the latter was chosen as the preferred antibiotic in such cases from 2015 onwards.

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We read with interest the letter by Mr Lance Gravatt in the December 16th 2016 issue of the Journal titled “Urinary alkalisers for cystitis—fact or fiction?”.1 While the fundamental message about the lack of evidence base for routine use of alkalisers for cystitis is reflected well in the letter, there are a few points that we wish to highlight.

Firstly, there are a few inaccuracies in the introductory statement of the letter where our study2 is referenced. The study setting was at Waitakere hospital in West Auckland and not Auckland City Hospital.
New cases of infection were identified over two separate 24 hour periods and not during a single day. There were 81 admissions where any infection was the primary or secondary reason for hospitalisation. Urinary tract infections (UTI) contributed to only 22% (n=18) of these cases. The letter mentions 81 UTIs instead.
The mean length of hospital stay was 5.5 and 12.5 days for medical and rehabilitation patients respectively, and not four days.
Furthermore, it is our view that this reference seems to be somewhat irrelevant to the topic of this letter, which focuses predominantly on outpatient treatment of uncomplicated cystitis.

Secondly, it is worth noting that the activity of certain antibiotics may be affected by changes in urinary pH. Examples include nitrofurantoin (a commonly used antibiotic for treatment of cystitis), which has maximal antibacterial activity in acidic urine, while aminoglycosides and co-trimoxazole demonstrate greater activity against common urinary pathogens with increasing pH.3

Thirdly, we like to draw the reader’s attention to increasing use of restricted antibiotics like pivmecillinam and fosfomycin in both hospital and community settings to treat extended spectrum beta-lactamase producing (ESBL) E.coli and klebsiella pneumoniae bacteria. Such antibiotics are not affected by urinary alkalisers, and are often used when other oral options are limited due to either resistance or drug intolerance issues. A retrospective review4 performed at North Shore Hospital between June 2014 and October 2015 revealed that 70 inpatients with uncomplicated ESBL UTIs (resistant also to nitrofurantoin and norfloxacin) were treated with either fosfomycin (n=42) or pivmecillinam (n=28), after the latter was chosen as the preferred antibiotic in such cases from 2015 onwards.

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