Continuous ampicillin infusion as an alternative to intermittent infusion for adult inpatients: a case series.

Intravenous ampicillin has been extensively used for various kinds of infections for more than fifty years. This drug is administered intermittently, which can result in missed or delayed drug administration and sleep interruption that can have a negative impact on the quality of life during hospitalization. Continuous infusion may solve these concerns. We reviewed the cases of five patients who were treated with continuous ampicillin infusions in our hospital. The ampicillin serum concentrations were from 11.3 to 32.8 μg/mL, which was above the ampicillin MICs of the causative organisms, ≤0.06 to 4 μg/mL. Although the dosages given of ampicillin varied in each case, the serum concentrations showed a strong correlation with creatinine clearance (r(2) = 0.91). All the patients improved at the time of discharge, or transfer to another hospital, with no significant complications during the continuous infusion. Continuous ampicillin infusion could be a better alternative for frequent intermittent infusion for adult inpatients with infections due to ampicillin-susceptible organisms.