fosfomycin

Inactivates an enzyme crucial for bacterial cell wall synthesis.
Decreases adherence of bacteria to uroepithelial cells.

Therapeutic effects:

Bactericidal action against susceptible bacteria.

Spectrum:

Active against: Enterococcus faecalis and Escherichia coli.

Pharmacokinetics ⬆ ⬇

Absorption: Rapidly absorbed and converted to fosfomycin, its active component, resulting in 37% bioavailability.

Distribution: Distributes to kidneys and bladder wall; crosses the placenta.

Metabolism/Excretion: Excreted unchanged in urine (38%) and feces (18%).

Half-Life: 5.7 hr.

Time/Action Profile ⬆ ⬇

(bactericidal urine levels‡)

ROUTE	ONSET	PEAK	DURATION
PO	rapid	2–4 hr	unknown

‡Symptoms may take 24–48 hr to subside.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Pyelonephritis;
Lactation: Lactation.

Use Cautiously in:

OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk;
Pedi: Children <12 yr (safety and effectiveness not established).

Adv. Reactions/Side Effects ⬆ ⬇

GI: dyspepsia, CLOSTRIDIOIDES DIFFICILE-ASSOCIATED DIARRHEA (CDAD), diarrhea, nausea

GU: vaginitis

Neuro: dizziness, headache, weakness

Interactions ⬆ ⬇

Drug-drug:

Urinary excretion and blood levels are ↓ by metoclopramide.

Route/Dosage ⬆ ⬇

PO (Adults ): 3 g as a single dose.

Availability ⬆ ⬇

(Generic available)

Granules for oral solution: 3 g/sachet

Assessment ⬆ ⬇

Assess for signs and symptoms of cystitis resolution.
Monitor for diarrhea, abdominal cramping, fever, and bloody stools. May begin up to several wk following cessation of therapy. If CDAD suspected or confirmed, consider discontinuing fosfomycin and treat as indicated.

Lab Test Considerations:

Obtain urine for culture and sensitivity before administration.

Implementation ⬆ ⬇

PO: Do not take medication in dry form. Pour entire contents of single sachet into 3–4 ounces (½ cup) of water. Stir to dissolve. Do not use hot water. Drink immediately after mixing. May be administered without regard to food.

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of medication and correct preparation of sachet. Advise patient to read Patient Information before starting therapy.
Instruct patient to notify health care professional immediately if diarrhea, abdominal cramping, fever, or bloody stools occur and not to treat with antidiarrheals without consulting health care professional.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking other medications.
Rep: Advise women of reproductive potential to notify health care professional if pregnancy is planned or suspected and to avoid breastfeeding during therapy.
Advise patient to notify health care professional if cystitis symptoms have not improved or persist >2–3 days after treatment.

Evaluation/Desired Outcomes ⬆ ⬇

Improvement in symptoms of acute cystitis within 2–3 days.

Canadian Brand Names ⬆ ⬇

Code ⬆

NDC Code

12836- Ercros SA
- 12836-0317-
  - 12836-0317-1- 15 kg in 1 DRUM (12836-0317-1)

12836- Ercros SA
- 12836-0318-
  - 12836-0318-1- 20 kg in 1 DOSE PACK (12836-0318-1)

50090- A-S Medication Solutions
- 50090-6130- Fosfomycin Tromethamine
  - 50090-6130-0- 1 PACKET in 1 CARTON (50090-6130-0) / 1 GRANULE, FOR SOLUTION in 1 PACKET

50379- MSN Organics Private Limited
- 50379-0029-
  - 50379-0029-1- 60 kg in 1 DRUM (50379-0029-1)

50379- MSN Organics Private Limited
- 50379-0030-
  50379-0030-1- 60 kg in 1 DRUM (50379-0030-1)

53069- Quimica Sintetica S.A.
- 53069-1080-
  53069-1080-5- 10 kg in 1 DRUM (53069-1080-5)

60219- Amneal Pharmaceuticals NY LLC
- 60219-3955- Fosfomycin Tromethamine
  60219-3955-1- 1 PACKET in 1 CARTON (60219-3955-1) / 1 GRANULE, FOR SOLUTION in 1 PACKET (60219-3955-3)

67877- Ascend Laboratories, LLC
- 67877-749- Fosfomycin Tromethamine
  - 67877-749-57- 1 PACKET in 1 CARTON (67877-749-57) / 1 GRANULE, FOR SOLUTION in 1 PACKET

69037- Honour Lab Limited
- 69037-0066-
  - 69037-0066-1- 20 kg in 1 DRUM (69037-0066-1)

69097- Cipla USA Inc.
- 69097-579- FOSFOMYCIN TROMETHAMINE
  69097-579-67- 1 DOSE PACK in 1 CARTON (69097-579-67) / 1 GRANULE, FOR SOLUTION in 1 DOSE PACK

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇