Efficacy and safety profile of long-term nitrofurantoin in urinary infections: 18 years' experience.
Case records from 219 female patients between 1975 and 1992 who were given long-term prophylaxis (1 year) with nitrofurantoin for the prevention of recurrent urinary infections have been reviewed. Patients' age ranged from 9 to 89 years (median 31-35 years, mode 26-30 years); most (61%) were < 40 years old. The median number of symptomatic episodes in the 12 months immediately before prophylaxis was six (mode 4, mean 6.9). 14.4% of the patients were allergic to an antibiotic, and 23.6% had an imaging abnormality. Three regimens were used: group A (43 patients), 50 mg microcrystalline nitrofurantoin, bd; group B (110 patients), 100 mg macrocrystalline nitrofurantoin (Macrodantin), od; group C (66 patients), 50 mg Macrodantin, od. There were no obvious differences in efficacy between the patient groups (173 assessable patients). The mean incidence of symptomatic episodes decreased 5.4-fold during prophylaxis. Four-fifths of the 43 breakthrough infections (mostly due to Escherichia coli), were caused by nitrofurantoin-sensitive strains. An important finding was that patients with an imaging abnormality responded as well as those with no such abnormalities. In 16% of patients, prophylaxis was not helpful, objectively or subjectively, for no obvious reasons. In most patients where prophylaxis was successful, clinical improvement was maintained for at least 6 months after the end of prophylaxis. Nausea was more common in group A (P < 0.001), as were 'all adverse events'. Of those in group A 25.6% stopped prematurely as a result of an adverse event of any type, compared with 13% of those taking Macrodantin (P < 0.01). Older patients (> 65 years) did not report more adverse events than younger patients. No adverse event was life-threatening. Faecal flora analysis showed neither overgrowth by nitrofurantoin-resistant bacteria nor elimination of sensitive coliforms. Thus, macrocrystalline nitrofurantoin 50 mg at bedtime is appropriate for use in the long-term (12 months) prophylaxis of recurrent urinary infections, in view of its efficacy and favourable safety and tolerability profile. Patients can be managed by their family doctor.
Brumfitt
W
W
Urinary Infection Clinic, Royal Free Hampstead NHS Trust, and Department of Medical Microbiology, Royal Free Hospital School of Medicine, London, UK.
Hamilton-Miller
J M
JM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000892:Anti-Infective Agents, Urinary / Q000009:adverse effects / Q000627:therapeutic use*; D001437:Bacteriuria / Q000382:microbiology; D002648:Child; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009582:Nitrofurantoin / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014552:Urinary Tract Infections / Q000382:microbiology / Q000517:prevention & control*
D000892:Anti-Infective Agents, Urinary; D009582:Nitrofurantoin