Nitrofurantoin confirmation

While there is a clear connection between adenoma formation and the intake of oestrogens, the association between FNH and oestrogens, albeit plausible, still lacks confirmation. However, our own observations strongly suggest a causal relationship, (s. figs. 29.12, 29.13) FNH may also be caused by azathioprine, clofi-brate and nitrofurantoin. 

While taking nitrofurantoin after urinary tract surgery, a 10-year-old girl developed diplopia and ptosis (34). A sleep test confirmed ocular myasthenia. Her signs and symptoms resolved after drug withdrawal. 

A few cases of nitrofurantoin-induced acute pancreatitis, confirmed by rechallenge, have been reported (67). 

Forty eight (30%) of the E. faecium isolates, two (3%) of the E. durans isolates, and six (12%) of the E. faecalis isolates exhibited multidrug resistance. Ten percent of E. faecium, 0% of E. durans, and 17% of E. faecalis strains showed simultaneous resistance to three drugs (rifampicin, erythromycin, and ciprofloxacin or nitrofurantoin). For all E. faecium, E. durans, and E. faecalis isolates, 55 (19%) multidrug resistant strains were resistant to rifampicin, 55 (19%) strains were resistant to erythromycin, nine (2%) strains were resistant to ciprofloxacin, and one (0.3%) strain was resistant to nitrofurantoin. The incidence of multiple resistance to five or more antimicrobials of enterococcal cheese isolates was confirmed by Teuber et al. (1999) and Franz et al. (2001). In this respect it may be stated that the enterococcal isolates from Bryndza cheese have simultaneous resistance to fewer antimicrobials compared to the above-mentioned cheese isolates. 

A study of the way the kidneys handle nitrofurantoin found that intravenous sulfinpyrazone 2.5 mg/kg reduced the secretion of nitrofurantoin by the kidney tubules by about 50%. Thi s reduction would be expected to reduce its urinary antibacterial efficacy, and the higher serum levels might lead to increased systemic toxicity, but there do not seem to be any reports suggesting that this represents a real problem in practice. The same situation would also seem likely with probenecid, but there do not appear to be any reports confirming this interaction. 

A crossover study in 6 healthy subjects confirmed that aluminium hydroxide gel does not affect the absorption of nitrofurantoin from the gut (as measured by its excretion into the urine). Another study in 10 healthy subjects found that an antacid containing aluminium hydroxide, magnesium carbonate and magnesium hydroxide reduced the absorption of nitrofurantoin by 22%. ... 

Information appears to be limited to these reports. There seems to be nothing in the literature confirming that a clinically important interaction occurs between nitrofurantoin and antacids. One reviewer offers the opinion that common antacid preparations are unlikely to interact with nitrofurantoin. ... 

It is not yet known whether magnesium trisilicate significantly reduces the antibacterial effectiveness of nitrofurantoin but the response should be monitored. While it is known that the antibacterial action of nitrofurantoin is increased by drugs that acidify the urine (so that reduced actions would be expected if the urine were made more alkaline by antacids) this again does not seem to have been confirmed. The results of the in vitro studies suggest that the possible effects of the other antacids are quite small, and aluminium hydroxide is reported not to interact. 

The antibaeterial aetivily of nalidixic acid can be attenuated by sub-inhibitory concentrations of nitrofurantoin. In 44 out of 53 strains of Escherichia coli. Salmonella and Proteus, antagonism was shown. Another study confirmed these findings. Whether this similarly occurs if both antibacterials are given to patients is uncertain, but the advice that concurrent use should be avoided when treating urinary tract infections seems sound. Active division of bacteria is required for the bactericidal activity of quinolones sttch as nalidixic acid, and the presence of a bacte-... 

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