Dosing
It comes in the ever so quaint sachet.
Women: years: 3 g PO once. I suspect this is insufficient and likely cystitis needs 3 or more doses, which is why it was inferior to nitrofurantoin for UTI (PubMed).
Males: 3 g every 2-3 days for 3 doses.
IV is 8-24 grams a day. IV not available in US.
Important side effects
IV has a lot of sodium.
Important drug interactions
Rants and Screeds
Pearls
It can be synergistic with beta-lactams.
Effective against E. faecalis, E. coli, Citrobacter and Proteus. Pseudomonas may have more ability to be resistant, but less perhaps than other antibiotics.
May be useful with MDRO and XDR (PubMed).
Resistance is rare in the US but common in China. US resistance variable, more in Klebsiella than E. coli (Review).
Treatment of choice
Use for
Maybe prostatitis, where it is given for 6 to 8 weeks.
Don't use for
Pyelonephritis.
Class
Phosphonic acid derivative, it inhibits bacterial cell wall synthesis.
Curious Cases
Relevant links to my Medscape blog
Last update 11/25/19