hydromorphone

Brand: Dilaudid, Exalgo

⚠ BBW ISMP High Alert Prototype: morphine
Drug Class: opioid analgesic
Drug Family: opioid
Subclass: semi-synthetic mu-opioid agonist
Organ Systems: cns

Mechanism of Action

Potent full agonist at mu-opioid receptors; 5-8 times more potent than morphine on a weight-for-weight basis. Rapidly crosses the blood-brain barrier due to higher lipophilicity compared to morphine, contributing to its rapid onset and potential for euphoria.

mu-opioid receptor (MOR)kappa-opioid receptor (KOR)

Indications

  • moderate to severe pain
  • post-operative pain

Contraindications

  • respiratory depression without resuscitation equipment
  • acute or severe asthma
  • gastrointestinal obstruction
  • concurrent MAOI use

Adverse Effects

Common

  • sedation
  • nausea
  • vomiting
  • constipation
  • pruritus
  • dizziness

Serious

  • respiratory depression (dose-limiting toxicity)
  • opioid use disorder
  • hypotension
  • seizures at high doses

Pharmacokinetics (ADME)

Absorption well absorbed; IV/SC/IM/oral routes available; oral bioavailability ~24% due to first-pass
Distribution protein binding ~8-19%; crosses BBB rapidly
Metabolism hepatic glucuronidation (not CYP-dependent); active metabolite hydromorphone-6-glucuronide (neuroexcitatory at high doses)
Excretion primarily renal
Half-life 2-3 hours
Onset IV: 5 minutes; oral: 15-30 minutes
Peak IV: 15-30 minutes; oral: 30-60 minutes
Duration 4-5 hours
Protein Binding 8-19%
Vd 4 L/kg

Drug Interactions

Drug / Agent Mechanism Severity
CNS depressants (benzodiazepines, alcohol) additive respiratory depression and CNS depression major
MAOIs excitatory serotonin-like syndrome contraindicated
naloxone/naltrexone reversal of opioid effects; precipitation of withdrawal major

Nursing Considerations

  1. Equianalgesic dosing: IV hydromorphone 0.2 mg = IV morphine 1 mg = PO morphine 3 mg; use equianalgesic tables when rotating opioids to avoid under- or over-dosing.
  2. Monitor respiratory rate and oxygen saturation; withhold and notify prescriber if respiratory rate <10/min or SpO2 <92%.
  3. Hydromorphone is the most common opioid involved in 10-fold IV dosing errors due to its potency and vial concentration variability; double-check vial concentration and dose calculation with a second nurse.
  4. Reassess pain at 30-60 minutes after IV administration and at peak effect time to evaluate efficacy and guide next dosing interval.

Clinical Pearls

  • Hydromorphone 0.2 mg IV is equianalgesic to morphine 1 mg IV; this 5-fold potency difference makes dose calculation errors particularly dangerous — organizations have implemented double-check policies specifically for hydromorphone.
  • Unlike morphine, hydromorphone lacks active metabolites that accumulate in renal failure at equianalgesic doses, making it preferred in patients with moderate renal impairment when parenteral opioid is required.

Safety Profile

Pregnancy avoid
Lactation use-with-caution
Renal Adjustment Required
Hepatic Adjustment Required
TDM Not required

Concordance Terms

Cross-referenced clinical concepts — click any term to see all content where it appears.