Onset of Action of Intravenous Hydrocortisone
Following intravenous injection of hydrocortisone sodium succinate, demonstrable effects are evident within one hour. 1
Pharmacokinetic Profile
The FDA-approved drug label provides specific timing data for IV hydrocortisone:
- Onset of demonstrable effects occurs within 1 hour after intravenous injection 1
- Effects persist for a variable period, with nearly complete excretion of the administered dose within 12 hours 1
- The highly water-soluble sodium succinate ester formulation permits immediate intravenous administration and is particularly useful where high blood levels are required rapidly 1
Clinical Implications for Dosing Frequency
- To maintain constantly high blood levels, injections should be administered every 4 to 6 hours 1
- This dosing interval is necessary because excretion follows a pattern where the drug is nearly completely eliminated within 12 hours 1
Clinical Context in Life-Threatening Conditions
In septic shock specifically, the clinical response timeline differs from pharmacokinetic onset:
- Hemodynamic stabilization typically occurs rapidly after IV bolus administration, as demonstrated in case reports where 100 mg IV hydrocortisone led to rapid hemodynamic stabilization in patients with refractory shock 2, 3
- For sustained effect in septic shock, continuous infusion of 200 mg/24 hours is preferred over intermittent boluses to maintain steady therapeutic levels 4, 5
Important Caveat
While pharmacologic effects begin within 1 hour, the full therapeutic benefit in septic shock (shock reversal, vasopressor weaning) typically requires several hours to days of treatment at full doses 4, 6. The one-hour onset refers to measurable drug effects, not necessarily complete clinical resolution of the underlying critical illness.