Antimicrobials
Ampicillin

Ampicillin

Medium
Moderate (40 to 70%)
IV: $$ ($26-$100/day)

Spectrum of Activity

Dosing

General Information

  • Allergic reactions

  • Diarrhea, nausea, vomiting

  • Absorption: Oral: 50%

  • Distribution: Into bile; penetration into CSF occurs with inflamed meninges only

  • Protein binding: 15% to 18%

  • Half-life elimination: 1 to 1.8 hours; Anuric patients: 8 to 20 hours

  • Time to peak serum concentration: Oral: Within 1 to 2 hours

  • Excretion: Urine (∼90%, unchanged within 24 hours); feces

For oral therapy, including oral step-down therapy after IV ampicillin, oral amoxicillin is preferred over oral ampicillin due to improved bioavailability and absorption