nitrofurantoin is an antibiotic used in the short term Rx of urinary tract infections (UTIs) / cystitis and is generally regarded as a 4th line antibiotic after trimethoprim, cephalexin, and amoxycillin/clavulanic acid
it is active against Gram positive and Gram negative urinary tract pathogens, particularly E. coli, but Ps. aeruginosa and some Klebsiella, Aerobacter and Proteus strains are insensitive.
category A (safe) in pregnancy (except when labour is imminent - see below)
P/K
only slightly soluble in water but solubility increases in acidic environments
concurrent antacids may impair absorption
Macrodantin (nitrofurantoin macrocrystals) is a larger crystal form of Furadantin (nitrofurantoin), and it has slower absorption from GIT and less excretion resulting in less nausea
urinary levels rise above MIC for ~6hrs
bacteria develop limited resistance
C/I
NOT for long term use as risk of peripheral neuropathy and pulmonary toxicity especially in the elderly
although is safe in pregnancy, it should NOT be used when labour is imminent or to infants under 1 month as risk of neonatal haemolytic anaemia
anuria or oliguria
creatinine clearance < 60 mL/minute
labour
neonates
long term use
hypersensitivity to nitrofurantoin
does not reach high plasma levels thus may not Rx urosepsis
will not Rx renal or perinephric abscesses, nor prostatitis
adverse effects
nausea
peripheral neuropathy if longer duration Rx
pulmonary toxicity if longer duration Rx
hepatitis
haemolytic anaemia - neonates and patients with G6PD deficiency