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Hydromorphone Facts

Opioid; Depressant; Substituted morphinan; Mu-opioid receptor agonist

Description

Hydromorphone (dihydromorphinone) is a semi-synthetic opioid of the morphinan class. It activates opioid receptors in the brain and spinal cord, suppressing pain signaling and producing sedation and euphoria.[1]

Subjective effects include profound pain suppression, euphoria, heavy sedation, physical warmth, and the dissolution of anxiety into a deep calm. The experience is defined by what it removes — pain and distress dissolve into a weighted, enveloping quiet, most intensely when delivered intravenously.[2]

Hydromorphone produces physical dependence quickly, and the gap between a therapeutic dose and a fatal one is dangerously narrow. Tolerance to pain relief builds faster than tolerance to stopped breathing, so escalating the dose steadily narrows the safety margin; adding alcohol or benzodiazepines makes the combination acutely lethal.[3]

Dose and durationby route · individual sensitivity varies

Oral(mg)
Threshold< 0.5 mgLight1 – 2 mgCommon2 – 4 mgStrong4 – 8 mgHeavy8+ mg

Starts in 15 – 30 minLasts 3 – 5 hoursAfter-effects 1 – 12 hours

Body and dependence

Acute toxicity
High
Chronic toxicity
High
Physical dependence
High
Psychological dependence
High
Withdrawal
Severe · medical supervision
Compulsive redosing
High

Tolerance

Builds
Rapid
Fully resets after
14 days
Carries over to
morphine; oxycodone; fentanyl; heroin; hydrocodone; methadone

Effectslikely at a common dose

Perception
Sleep-transition hallucinations; +2 possible, including Visual acuity suppression
Body
Sedation; Constipation; Pain suppression; Pupil constriction; Bodily heaviness; Body high; Breathing alteration; +18 possible, including Respiratory depression, Nausea, Dizziness
Thinking
none likely · 16 possible, including Cognitive impairment, Decision impairment, Information processing suppression
Feeling
Euphoria; +5 possible, including Empathy suppression, Anxiety, Dysphoria
Self
none likely · 5 possible, including Craving, Communication suppression, Social disconnection
Time
none likely · 2 possible, including Temporal disorientation

Who shouldn't take it

Absolute
Significant respiratory compromise; Known hypersensitivity to hydromorphone or sulfite excipients; Gastrointestinal obstruction or paralytic ileus; MAO inhibitor use within 14 days
Relative
Head injury with raised intracranial pressure; Hepatic impairment; Renal impairment; Pregnancy; Elderly patients; Concurrent CNS depressant use

Combinations62 recorded

Lethal (6)
Benzodiazepines, Barbiturates; GHB, Baclofen; GHB, GBL; Ketamine; Local anesthetics; Tramadol
Dangerous (39)
Antihistamines; Benzodiazepines; Buprenorphine, Kratom; Cannabis, THC; Gabapentin, Pregabalin; MDMA, Amphetamines; Naltrexone; NRIs; Stimulants; THC; 5-HTP, Tryptophan; Alpha-2 adrenergic receptor antagonist; Amphetamines; Anticholinergics; Antipsychotics; Atypical antipsychotics; Buspirone; Caffeine; Cannabis; CBD; Dopamine agonists; DXM; Ephedrine, Pseudoephedrine; Glutamate modulator; and 15 more, see full page
Caution (12)
See full page: psychedex.org/substances/hydromorphone
Not graded (5)
Not listed never means safe.

Seek help immediately if

  • Unresponsive / can't be woken, even to a firm sternal rub
  • Slow, shallow, or stopped breathing
  • Pinpoint pupils
  • Blue/grey lips, fingertips, or skin (cyanosis)
  • Limp body; pale, clammy skin
  • Choking or gurgling sounds ("death rattle")
  • Slow, erratic, or absent pulse

What to do

  1. Try to wake them — shout their name, firm sternal rub
  2. Call emergency services immediately
  3. Administer naloxone if available
  4. Give rescue breaths (or CPR if there is no pulse)
  5. Place them in the recovery position
  6. Stay with them; re-dose naloxone every 2–3 minutes if there is no response
Reversal agent
Naloxone (Narcan) — opioid antagonist. May require repeated doses; its effect can wear off before the opioid does.

With prompt naloxone and rescue breathing, reversal is usually rapid. Because naloxone can wear off before the opioid — especially with long-acting opioids (methadone) or high-potency ones (fentanyl) — a period of monitoring is needed even after the person revives.

988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE

Version r1 · Not medical advice

References

  1. [1]
    ^Volpe DA, McMahon Tobin GA, Mellon RD, et al. (2011) Uniform assessment and ranking of opioid mu receptor binding constants for selected opioid drugs — Regulatory Toxicology and Pharmacology doi:10.1016/j.yrtph.2010.12.007
  2. [2]
    ^Mazer-Amirshahi M, Motov S, Nelson LS (2018) Hydromorphone use for acute pain: Misconceptions, controversies, and risks — Journal of Opioid Management doi:10.5055/jom.2018.0430
  3. [3]
    ^Smith MT (2000) Neuroexcitatory effects of morphine and hydromorphone: evidence implicating the 3-glucuronide metabolites — Clinical and Experimental Pharmacology & Physiology PMID:10874511
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