Immediate-Release Dilaudid (Hydromorphone) Dosing Interval
Immediate-release Dilaudid (hydromorphone) should be dosed every 4 to 6 hours based on its duration of action. 1
Duration of Action
- Immediate-release hydromorphone has a duration of action of 4-5 hours after oral administration 1
- The onset of action occurs within 15-30 minutes of administration 1
- Peak plasma concentrations are achieved within ½ to 1 hour after oral dosing, with the terminal elimination half-life approximately 2.3 to 2.6 hours 2
Clinical Pharmacology
- After oral administration of immediate-release hydromorphone, the analgesic effects peak within 1.5 hours and are maintained at greater than 50% of peak effect for approximately 3.6 hours 3
- The short duration necessitates frequent dosing every 4 hours with conventional immediate-release formulations to provide sustained pain relief 3
- Hydromorphone undergoes extensive first-pass metabolism with approximately 24% bioavailability after oral administration 2
Comparison with Extended-Release Formulation
- Extended-release hydromorphone formulations provide once-daily dosing by maintaining therapeutic levels for over 20 hours, contrasting sharply with the 4-6 hour duration of immediate-release formulations 1, 4
- When converting from immediate-release to extended-release, the total daily dose remains the same but is administered once daily rather than divided into multiple doses 4
Important Caveats
- In patients with moderate hepatic impairment (Child-Pugh B), exposure increases 4-fold, requiring lower starting doses and extended dosing intervals 2
- In patients with severe renal impairment (CrCl <30 mL/min), the elimination half-life extends to approximately 40 hours compared to 15 hours in normal function, necessitating significantly longer dosing intervals 2
- The 4-6 hour dosing interval applies to patients with normal hepatic and renal function; dose adjustments and interval extensions are mandatory in organ dysfunction 1, 2