Fosfomycin

INTRODUCTION

Indications

Uncomplicated urinary tract infections in women (acute cystitis).

Action

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.

Adverse Reactions/Side Effects

CNS: dizziness, headache, weakness. GI: PSEUDOMEMBRANOUS COLITIS, diarrhea, dyspepsia, nausea. GU: vaginitis.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Be alert for signs of pseudomembranous colitis, including diarrhea, abdominal pain, fever, pus or mucus in stools, or other severe or prolonged GI problems (nausea, cramps, vomiting). Notify physician immediately if these signs occur.

• Assess dizziness and weakness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.

Interventions

• Always wash hands thoroughly and disinfect equipment (whirlpools, electrotherapeutic devices, treatment tables, and so forth) to help prevent the spread of infection. Employ universal precautions or isolation procedures as indicated for specific patients.

Patient/Client-Related Instruction

• Instruct patient to report other bothersome side effects such as severe or prolonged headache, vaginal irritation, or GI problems (nausea, diarrhea, indigestion).

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

Half-life: 5.7 hr.

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Pyelonephritis; Lactation: Lactation.

Use Cautiously in: OB/Pedi: Pregnancy or children <12 yr (safety not established).

Interactions

Drug-Drug: Urinary excretion and blood levels are ↓ by metoclopramide.

Route/Dosage

PO (Adults and Children ≥18 yr): 3 g single dose.

Availability

Sachet: 3 g.