Related Experiment Video
Updated: Jun 3, 2026

In Vivo Real-Time Study of Drug Effects on Carotid Blood Flow in the Ovine Fetus
Published on: April 28, 2023
Time-course effect of a single dose of hydrocortisone for refractory hypotension in preterm infants
Masami Mizobuchi1, Seiji Yoshimoto, Hideto Nakao
1Department of Neonatology, Hyogo Prefectural Kobe Children's Hospital Perinatal Center, Kobe, Japan. mizobuchi_kch@hp.pref.hyogo.jp
Background:
The aim of this study was to determine the time-course effect of a single dose of hydrocortisone (HC) on arterial blood pressure in extremely low gestational age newborns (ELGAN) with refractory hypotension during the first 3 days of life.
Methods:
We carried out a matched case-control study of a cohort of 116 infants born between 23 and 27 weeks' gestation at a tertiary center. Twelve infants (10%) were treated with HC for refractory hypotension (HC group). HC was administered at a dose of 2 mg/kg when mean arterial pressure (MAP) was below 30 mmHg (25 mmHg for infants <25 weeks of gestational age) despite the use of inotropes and volume expanders. Changes in the MAP after the HC administration were compared with those in the infants who were not treated with HC and matched for gestational age (Control group).
Results:
The mean MAP before administration of HC was significantly lower in the HC group than that in the control group (24.0 ± 3.2 vs 33.3 ± 4.8 mmHg; P < 0.01). The mean MAP in the HC group increased significantly at 2 h after HC treatment, and then reached levels comparable to those in the Control group at 5 h (31.3 ± 4.0 vs 33.9 ± 4.7 mmHg; P= 0.18), and remained at normal levels until 12 h after HC treatment.
Conclusion:
A single dose of HC treatment induces a rapid and sustained improvement in blood pressure in ELGAN with refractory hypotension.
Related Concept Videos
Drug Dosing: Infants and Children
Time Course of Drug Effect
Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
Drugs for Treatment of Crohn's Disease in IBD Using Glucocorticoids
Factors Affecting Drug Response: Overview
Desensitization and Tachyphylaxis
Several...
