Fosfomycin
MONUROL
Pronunciation: fos-foe-MYE-sin
What it isInhibitor of an early step in cell wall synthesis; uncomplicated cystitis.
Why this oneA single oral dose treats cystitis, and it retains activity against many multidrug-resistant organisms.
What limits itIt concentrates only in urine, so it is useless for pyelonephritis or systemic infection.
FDA-approved for
- uncomplicated urinary tract infection (1996)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Uncomplicated UTI (acute cystitis) | Women ≥18 y | One 3 g sachet single dose | One 3 g sachet single dose | One 3 g sachet single dose |
Renal Undefined
Hepatic Undefined
Single-dose therapy; do not use multiple doses to treat a single episode of acute cystitis.
Instructions
- Take with or without food
- Mix granules with water (about 3-4 oz) before ingesting; do not take dry
Available strengths
- sol 3 g/packet
- granules 3000 mg
- powder 3000 mg
- inj 6 g
Cautions
- Single-dose therapy only; multiple doses not more effective
- Diarrhea/Clostridioides difficile-associated diarrhea
- Hypersensitivity reactions
Adverse reactions
- Diarrhea
- Vaginitis
- Nausea
- Headache
- Dizziness
- Asthenia
- Dyspepsia
Pregnancy Crosses the placental barrier; not teratogenic in animal studies.
Lactation Undefined
Cost
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 3 g/packet | sol | per unit | $26.22/ea | offered |
Generic entry2020
NO BOXED WARNINGS
Principal riskUrine only, so useless in pyelonephritis
Classes and tags
Clinical profile
Legacy pregnancy categoryUnknown / historical label unavailable
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.