Hydromorphone: Complete Drug Monograph

Pharmacokinetic Profile

Half-Life

2–3 h (IR oral/IV); 8–15 h (ER)

Metabolism

Hepatic glucuronidation (UGT2B7); not CYP-dependent

Protein Binding

8–19%

Bioavailability

~24% oral (range 20–50%)

Volume of Distribution

~303 L (~4 L/kg)

Clinical Information

Drug Class

Opioid agonist (mu-receptor)

Available Doses

IR tabs: 2, 4, 8 mg; ER tabs: 8, 12, 16, 32 mg; Oral liquid: 1 mg/mL; Inj: 1, 2, 4, 10 mg/mL

Route

PO, IV, IM, SC, PR

Renal Adjustment

Start at 25–50% of usual dose

Hepatic Adjustment

Start at 25–50% of usual dose

Pregnancy

Avoid; NOWS risk with prolonged use

Lactation

Excreted in breast milk; not recommended

Schedule

DEA Schedule II

Generic Available

Yes

Black Box Warning

Yes — multiple

Therapeutic Index

Narrow

Indications

Indication	Approved Population	Therapy Type	Status
Moderate-to-severe acute pain requiring opioid analgesia when alternatives are inadequate	Adults	Monotherapy or adjunctive to multimodal analgesia	FDA Approved
Severe chronic pain requiring continuous around-the-clock opioid treatment (ER formulation)	Opioid-tolerant adults	Monotherapy (ER only for opioid-tolerant patients)	FDA Approved

Hydromorphone is a potent semi-synthetic opioid reserved for pain that has not responded adequately to non-opioid analgesics or where non-opioid approaches are expected to be insufficient. The immediate-release formulation is typically used for acute settings such as post-surgical, trauma, or cancer-related pain. The extended-release formulation (Exalgo) is indicated exclusively for patients already established on and tolerant to opioid therapy, defined as those receiving the equivalent of at least 60 mg oral morphine daily for one week or longer. Hydromorphone should not be used as an as-needed analgesic or for mild pain.

Off-Label Uses

Refractory cough suppression — Hydromorphone may be considered for intractable cough in palliative care settings when codeine and dextromethorphan have failed. Evidence quality: Low.

Refractory dyspnoea in palliative care — Low-dose hydromorphone is sometimes used for breathlessness in end-stage disease when morphine is not tolerated. Evidence quality: Low.

Dose

Dosing

Adult Dosing — By Clinical Scenario

Clinical Scenario	Starting Dose	Maintenance Dose	Maximum Dose	Notes
Acute pain — opioid-naive, oral	2 mg PO q4–6h	2–4 mg PO q4–6h	Titrate to effect	Use lowest effective dose for shortest duration Oral liquid 1 mg/mL available; verify mg vs mL to avoid dosing errors
Acute pain — opioid-naive, parenteral	0.2–1 mg IV q2–3h	Titrate to effect	Titrate to effect	IV onset <5 min; administer slowly over 2–3 min IM/SC: 1–2 mg q2–3h as needed
Post-operative pain — IV PCA	0.2 mg demand dose	0.2–0.4 mg demand dose	Institutional protocol	Lockout interval typically 6–10 min Continuous basal infusion generally not recommended in opioid-naive patients
Chronic cancer pain — oral titration	2–4 mg PO q4–6h	Titrate by 25–50% increments	No ceiling for cancer pain	Titrate based on pain control and tolerability Convert to ER formulation once stable daily requirement established
Chronic pain — ER formulation (opioid-tolerant only)	8 mg PO q24h	Titrate q3–4 days by 25–50%	64 mg q24h	Start at 50% of calculated total daily HM dose Swallow whole; never crush, chew, or dissolve ER tablets
Palliative care — continuous SC infusion	0.5–1 mg/h SC	Titrate to comfort	No ceiling in end-of-life	Use concentrated solution (10 mg/mL) for SC infusion Useful when oral route compromised or high-dose morphine poorly tolerated

Special Population Adjustments

Clinical Scenario	Starting Dose	Maintenance Dose	Maximum Dose	Notes
Renal impairment (moderate–severe)	25–50% of standard starting dose	Titrate cautiously	Reduce proportionally	H3G metabolite accumulates in renal failure; risk of neuroexcitation Half-life may extend to ~40 h in severe impairment
Hepatic impairment (moderate)	25–50% of standard starting dose	Titrate cautiously	Reduce proportionally	Increased bioavailability due to reduced first-pass metabolism Severe hepatic impairment not studied; use with extreme caution
Elderly patients (≥65 years)	Reduce starting dose	Titrate slowly	Individual	Greater sensitivity to respiratory depression and CNS effects Higher incidence of constipation and nausea in elderly clinical trials

Clinical Pearl — Equianalgesic Conversion

Hydromorphone is approximately 5–7 times more potent than oral morphine. When converting, use 4 mg oral hydromorphone ≈ 20–30 mg oral morphine as a starting reference, then reduce the calculated dose by 25–50% to account for incomplete cross-tolerance. Conversion ratios vary substantially between patients; always titrate to clinical response rather than relying on a fixed ratio (FDA PI).

Critical Safety: Dilaudid-HP (10 mg/mL)

The high-potency injection formulation (Dilaudid-HP, 10 mg/mL) is reserved exclusively for opioid-tolerant patients. Administering HP to opioid-naive patients may cause fatal respiratory depression. Always confirm the concentration before administering any hydromorphone injection.

Pharmacology

Mechanism of Action

Hydromorphone is a semi-synthetic opioid derived from morphine through hydrogenation at the 7,8-position and oxidation of the 6-hydroxyl group. It functions as a full agonist at the mu-opioid receptor (MOR), with high affinity that mediates its analgesic, respiratory depressant, and euphoric effects. At the spinal level, hydromorphone activates presynaptic MOR on primary afferent C-fibre terminals, reducing substance P and glutamate release into the dorsal horn. Supraspinally, it activates descending inhibitory pathways originating in the periaqueductal grey matter and rostral ventromedial medulla, modulating pain transmission through noradrenergic and serotonergic projections. Hydromorphone also acts centrally at the medulla to suppress the cough reflex and depress respiratory drive by reducing chemoreceptor sensitivity to carbon dioxide. Unlike codeine or oxycodone, hydromorphone does not require CYP450-mediated activation, meaning its analgesic effect is not subject to the pharmacogenomic variability that characterises CYP2D6-dependent opioids.

ADME Profile

Parameter	Value	Clinical Implication
Absorption	Oral bioavailability ~24% (range 20–50%); Tmax 0.5–1 h (IR), 12–16 h (ER); food does not clinically affect absorption of ER formulation	Substantial first-pass metabolism means parenteral doses are significantly lower than oral; IR provides rapid onset for acute pain settings
Distribution	Vd ~303 L (~4 L/kg); protein binding 8–19%; lipophilic; crosses placenta and blood-brain barrier	Low protein binding means minimal displacement-type drug interactions; high Vd reflects extensive tissue distribution
Metabolism	Hepatic glucuronidation via UGT2B7 (>95%); primary metabolite: hydromorphone-3-glucuronide (H3G, inactive analgesic, neuroexcitatory); minor metabolites: dihydromorphine (<1%), dihydroisomorphine (~1%)	Not CYP450-dependent — very low potential for metabolic drug-drug interactions; H3G accumulation in renal failure can cause myoclonus and neuroexcitation
Elimination	t½ ~2.3 h (IV), ~2.6 h (oral IR), ~11 h (ER); clearance ~1.96 L/min; ~7% excreted unchanged in urine, remainder as glucuronide conjugates	Short IR half-life requires dosing every 4–6 h; ER formulation allows once-daily dosing; renal impairment prolongs elimination dramatically (up to ~40 h)

Side Effects

≥10% Very Common

Adverse Effect	Incidence	Clinical Note
Constipation	31%	Does not attenuate with continued use; initiate prophylactic bowel regimen at treatment start
Nausea	28%	Often most prominent during initiation and dose escalation; may improve over 1–2 weeks
Somnolence	15%	Dose-related; warn patients about driving and operating machinery; generally improves with tolerance
Vomiting	14%	More common during titration; anti-emetics may be needed short-term
Headache	13%	Usually self-limiting; assess for medication-overuse headache in chronic use
Dizziness	11%	Orthostatic component common; advise rising slowly from seated/lying position

1–10% Common

Adverse Effect	Incidence	Clinical Note
Pruritus	6%	Histamine-mediated; non-allergic in most cases; may respond to antihistamines
Sweating / Flushing	5%	Peripheral vasodilation effect; generally benign but troublesome to patients
Dry mouth	5%	Anticholinergic-type effect; encourage oral hydration and saliva substitutes
Abdominal pain	4%	May reflect increased biliary tract pressure from sphincter of Oddi spasm
Peripheral oedema	3%	More common in chronic use; evaluate for other causes
Euphoria / Dysphoria	3%	Euphoria contributes to abuse liability; dysphoria more common in ambulatory patients
Insomnia	3%	May reflect pain control issues or opioid-induced sleep disturbance
Dyspepsia	2%	Reduced GI motility contributes; manage with prokinetics if persistent

Serious Serious Adverse Effects (Regardless of Frequency)

Adverse Effect	Estimated Frequency	Typical Onset	Required Action
Respiratory depression	<5% (dose-dependent)	First 24–72 h or after dose increase	Hold dose; administer naloxone 0.4–2 mg IV q2–3 min; continuous monitoring; may need repeated dosing as hydromorphone duration may exceed naloxone
Serotonin syndrome	Rare	Hours to days after initiating serotonergic co-medication	Discontinue hydromorphone and serotonergic agent; supportive care; cyproheptadine may be considered
Adrenal insufficiency	Rare	Typically after >1 month of use	Morning cortisol; if confirmed, physiologic corticosteroid replacement and opioid taper
Severe hypotension / Syncope	Uncommon (~1%)	First doses or dose escalation	Reduce dose; IV fluids; avoid in patients with circulatory shock
Anaphylaxis / Severe allergic reaction	Very rare	Any time	Epinephrine; permanent discontinuation; note: formulations contain sulfites, which can trigger reactions in susceptible individuals
Seizures	Rare	Higher doses or renal impairment (H3G accumulation)	Reduce dose or discontinue; evaluate renal function; consider alternative opioid
Androgen deficiency	Unknown (chronic use)	Chronic use (>3 months)	Assess testosterone if symptomatic; endocrinology referral if clinically significant
Neonatal opioid withdrawal syndrome (NOWS)	Expected with prolonged maternal use	Within days of delivery	Neonatology team at delivery; neonatal monitoring and scoring; pharmacologic treatment per protocol

Discontinuation Discontinuation Rates

ER Clinical Programme (Adults, N=2,524)

~12.5%

Top reasons: nausea, vomiting, constipation, somnolence, dizziness

Open-Label Titration Phase (Low Back Pain, N=447)

~12%

Top reasons: GI intolerance, CNS effects, inadequate analgesia

Reason for Discontinuation	Incidence	Context
Nausea / Vomiting	3–5%	Most common GI-related reason; typically during initial titration
Constipation	2–3%	Often preventable with prophylactic bowel regimen
Somnolence / Dizziness	2–3%	CNS effects more common in elderly and with concurrent CNS depressants
Drug withdrawal syndrome	1–2%	Seen in randomised withdrawal phase of ER clinical trials

Managing Opioid-Induced Constipation

Constipation is the most persistent side effect and does not develop tolerance over time. Start a prophylactic bowel regimen (stimulant laxative plus stool softener) with the first hydromorphone prescription. If refractory, consider peripherally acting mu-opioid receptor antagonists (PAMORAs) such as naloxegol or methylnaltrexone. Adequate hydration and dietary fibre supplementation are helpful adjuncts but are typically insufficient as monotherapy.

Int

Drug Interactions

Hydromorphone is metabolised primarily by UGT2B7 glucuronidation and is not a substrate, inhibitor, or inducer of CYP450 enzymes. As a result, metabolic drug-drug interactions are uncommon compared with CYP-dependent opioids. However, clinically significant pharmacodynamic interactions are substantial, particularly with CNS depressants. The interactions below are organised by severity.

Major Benzodiazepines

MechanismAdditive CNS and respiratory depression

EffectProfound sedation, respiratory arrest, coma, and death

ManagementAvoid concurrent use where possible; if essential, use lowest effective doses of both and closely monitor respiratory status

FDA Boxed Warning

Major MAO Inhibitors

MechanismImpaired opioid metabolism and enhanced serotonergic effects

EffectUnpredictable potentiation of opioid effects, serotonin syndrome, respiratory depression

ManagementContraindicated; do not use hydromorphone within 14 days of MAOI therapy

FDA PI

Major Alcohol

MechanismAdditive CNS depression; may accelerate ER tablet release

EffectProfound sedation, respiratory depression; potentially fatal dose-dumping with ER formulation

ManagementCounsel against any alcohol use; absolute contraindication with ER formulation

FDA PI

Major Serotonergic Drugs (SSRIs, SNRIs, triptans, TCAs)

MechanismAdditive serotonergic activity at 5-HT receptors

EffectSerotonin syndrome: agitation, hyperthermia, tachycardia, clonus, diaphoresis

ManagementMonitor for serotonin syndrome symptoms; discontinue hydromorphone if suspected; use alternative analgesic

FDA PI

Major Mixed Agonist-Antagonist Opioids (buprenorphine, nalbuphine, butorphanol)

MechanismPartial agonism or antagonism at mu-receptor competes with full agonist

EffectReduced analgesic effect of hydromorphone; may precipitate acute withdrawal

ManagementAvoid concurrent use; if transitioning, ensure adequate washout period

FDA PI

Moderate Gabapentinoids (gabapentin, pregabalin)

MechanismAdditive CNS and respiratory depression

EffectIncreased sedation, respiratory depression, particularly in elderly or debilitated patients

ManagementUse lowest effective doses; monitor respiratory status closely during initiation

FDA PI

Moderate Anticholinergic Agents

MechanismAdditive reduction in gastrointestinal motility

EffectSevere constipation, paralytic ileus, urinary retention

ManagementMonitor for ileus symptoms; aggressive bowel regimen; avoid if possible in elderly

Lexicomp

Moderate Muscle Relaxants (cyclobenzaprine, baclofen)

MechanismAdditive CNS depression

EffectIncreased sedation, respiratory depression, fall risk

ManagementUse with caution; reduce doses if combined; monitor sedation level

Lexicomp

Minor Diuretics

MechanismOpioids may reduce efficacy of diuretics by inducing ADH release

EffectReduced diuretic response; potential for fluid retention

ManagementMonitor fluid balance and blood pressure; adjust diuretic dose as needed

FDA PI

Minor UGT2B7 Inhibitors (e.g., valproic acid, ketoconazole)

MechanismPotential inhibition of hydromorphone glucuronidation

EffectTheoretically increased hydromorphone levels; clinical significance uncertain

ManagementMonitor for enhanced opioid effects; limited clinical data available

Mechanistic / In vitro

Mon

Monitoring

Respiratory Rate & Sedation Level Continuously during first 24–72 h and after dose changes
Routine Assess respiratory rate (≥12 breaths/min target), oxygen saturation, and sedation using a validated scale (e.g., Pasero Opioid-Induced Sedation Scale). Highest risk during initiation and dose escalation.
Pain Assessment Every dose titration; routine visits
Routine Validated pain scales (NRS, VAS) to guide dose titration. Functional outcomes (mobility, sleep quality) should also be documented.
Bowel Function Every visit
Routine Assess for constipation and adherence to bowel regimen. Ask about stool frequency, consistency, and straining at each encounter.
Renal Function Baseline, then periodically
Routine Serum creatinine and eGFR. H3G metabolite accumulates in renal impairment, risking neuroexcitation, myoclonus, and seizures. Dose adjustment required.
Aberrant Behaviour Screening Before initiation and ongoing
Routine Use validated risk tools (e.g., ORT, SOAPP-R) before prescribing. Check prescription drug monitoring program (PDMP) at each visit. Urine drug screening per institutional protocol.
Blood Pressure At initiation and dose changes
Routine Hydromorphone can cause orthostatic hypotension, especially in volume-depleted or elderly patients. Monitor sitting and standing BP during dose titration.
Endocrine Function If symptomatic (fatigue, libido changes, amenorrhoea)
Trigger-based Chronic opioid use can suppress the HPA axis and gonadal function. Check morning cortisol and testosterone/LH/FSH if clinical suspicion arises.
Serotonin Syndrome Signs When starting or changing serotonergic co-medications
Trigger-based Monitor for agitation, hyperthermia, diaphoresis, tremor, clonus, and autonomic instability. Hunter criteria for diagnosis.

Contraindications & Cautions

Absolute Contraindications

Significant respiratory depression in unmonitored settings or without resuscitative equipment
Acute or severe bronchial asthma in an unmonitored environment or absence of resuscitative equipment
Known or suspected gastrointestinal obstruction, including paralytic ileus
Known hypersensitivity to hydromorphone, any formulation component, or sulfites
Concurrent MAOI use or within 14 days of discontinuation
ER formulation in opioid-naive patients — Exalgo is reserved exclusively for patients already tolerant to opioids

Relative Contraindications (Specialist Input Recommended)

Severe hepatic impairment — pharmacokinetics not studied; significantly increased bioavailability expected; risk-benefit documentation required
Severe renal impairment (eGFR <30) — H3G metabolite accumulation causes neuroexcitatory toxicity; specialist pain team or nephrology input advised
History of substance use disorder — use only with structured risk mitigation plan, frequent monitoring, PDMP checks, and documented informed consent
Head injury or raised intracranial pressure — hydromorphone may obscure neurological assessment and further elevate ICP through CO2 retention
Pregnancy (prolonged use) — risk of NOWS; neonatology team involvement required if continuation is essential

Use with Caution

Elderly or debilitated patients — increased sensitivity to respiratory and CNS depressant effects
COPD or cor pulmonale — further depression of respiratory drive; use reduced doses with monitoring
Hypotension or hypovolaemia — hydromorphone can exacerbate circulatory compromise
Biliary tract disease — may cause sphincter of Oddi spasm; avoid in acute pancreatitis unless specialist-directed
Seizure disorders — hydromorphone may lower seizure threshold; H3G accumulation is an additional risk in renal impairment
Myxoedema / Hypothyroidism — enhanced and prolonged opioid effects; reduce starting dose
Adrenocortical insufficiency (Addison disease) — reduced clearance and enhanced effects

FDA Boxed Warning Opioid Analgesic REMS — Addiction, Abuse, Misuse, and Respiratory Depression

Hydromorphone exposes users to risks of opioid addiction, abuse, and misuse, which can lead to overdose and death. Serious, life-threatening, or fatal respiratory depression may occur, particularly during initiation or after dose increases. Concomitant use with benzodiazepines or other CNS depressants may result in profound sedation, respiratory depression, coma, and death. Accidental ingestion of even one dose, especially by children, can result in fatal overdose. Prolonged use during pregnancy can cause neonatal opioid withdrawal syndrome. The FDA requires a Risk Evaluation and Mitigation Strategy (REMS) for all opioid analgesics.

FDA Boxed Warning — ER Formulation Exalgo: Opioid-Tolerant Patients Only; Do Not Crush

Exalgo (hydromorphone ER) must only be prescribed for opioid-tolerant patients. Crushing, chewing, or dissolving extended-release tablets causes rapid release and absorption of a potentially fatal dose of hydromorphone. Patients must swallow tablets whole.

Patient Counselling

Purpose of Therapy

Hydromorphone is a strong pain medication prescribed when other treatments have not provided adequate relief. It works by changing how the brain perceives pain signals. Because of its potency and potential for dependence, it should be taken exactly as directed and only for the condition for which it was prescribed. The goal is to improve function and quality of life while using the lowest effective dose for the shortest necessary duration.

How to Take

Immediate-release tablets or liquid should be taken at regular intervals as prescribed, typically every 4 to 6 hours. Extended-release tablets must be swallowed whole once daily at approximately the same time each day. Patients should never break, crush, chew, or dissolve ER tablets, as this can release a dangerous dose all at once. Taking hydromorphone with or without food is acceptable. Patients should measure oral liquid carefully using the supplied measuring device, paying close attention to the difference between milligrams and millilitres.

Drowsiness & Dizziness

Tell patient Sedation and dizziness are common initially but usually improve over the first few days as your body adjusts. Do not drive, operate heavy machinery, or make important decisions until you know how this medication affects you. Rise slowly from sitting or lying positions to reduce lightheadedness.

Call prescriber If sedation becomes excessive, you cannot stay awake for conversations, or experience confusion, slurred speech, or repeated falls.

Constipation

Tell patient Constipation is the most persistent side effect and does not improve on its own over time. Start the bowel regimen your prescriber recommends from the first day. Drink plenty of fluids and include fibre in your diet. You may need a stimulant laxative (e.g., senna) in addition to a stool softener.

Call prescriber If you have not had a bowel movement in 3 or more days, develop abdominal pain, bloating, nausea, or vomiting related to constipation.

Breathing Difficulties

Tell patient This medication can slow your breathing, especially when starting treatment, after a dose increase, or if combined with alcohol, sleeping pills, or anxiety medications. A family member or caregiver should be aware of the signs of slowed breathing: unusually slow or shallow breaths, blue lips or fingertips, or difficulty waking up.

Call prescriber Seek emergency help immediately if you or a caregiver notices very slow or irregular breathing, extreme drowsiness from which you cannot be roused, or blue discolouration of the skin. Have naloxone (Narcan) available if prescribed.

Nausea & Vomiting

Tell patient Nausea is common when starting hydromorphone and usually improves within the first 1–2 weeks. Taking the medication with a small amount of food may help. Your prescriber may recommend a short course of anti-nausea medication during the adjustment period.

Call prescriber If nausea or vomiting is severe enough that you cannot keep medication down, are unable to eat or drink, or persists beyond the first two weeks of treatment.

Safe Storage & Disposal

Tell patient Store hydromorphone in a locked location out of sight and reach of children and anyone for whom it was not prescribed. Accidental ingestion by a child can be fatal. When the medication is no longer needed, dispose of unused tablets by flushing them down the toilet or take them to a DEA-authorised take-back location. Never share this medication with others.

Call prescriber Immediately contact Poison Control (1-800-222-1222) or emergency services if accidental ingestion by a child or non-patient occurs.

Stopping the Medication

Tell patient If you have been taking hydromorphone for more than a few weeks, do not stop suddenly. Abrupt discontinuation can cause withdrawal symptoms including anxiety, sweating, muscle aches, runny nose, nausea, diarrhoea, and insomnia. Your prescriber will create a gradual taper schedule to minimise withdrawal.

Call prescriber If you experience significant withdrawal symptoms during a taper, or if you accidentally miss several doses.

Alcohol & Other Medications

Tell patient Do not drink alcohol while taking hydromorphone. The combination can cause dangerous slowing of breathing and may be fatal. Tell all your healthcare providers that you are taking hydromorphone before starting any new medication, including over-the-counter products and herbal supplements.

Call prescriber Before starting any new sedating medication (sleep aids, anxiety medications, muscle relaxants, antihistamines) while on hydromorphone.

Ref

Sources

Regulatory (PI / SmPC)

Hydromorphone hydrochloride tablets USP — Full prescribing information (Mallinckrodt Pharmaceuticals). DailyMed. DailyMed Primary reference for IR oral formulation dosing, contraindications, and adverse reactions.
Exalgo (hydromorphone HCl extended-release tablets) — Full prescribing information. FDA/Drugs@FDA. FDA Label Source for ER formulation pharmacokinetics, clinical trial adverse event rates, and opioid-tolerant patient definitions.
Hydromorphone hydrochloride injection — Full prescribing information (Pfizer). FDA Label Reference for parenteral dosing, IV/IM/SC administration guidance, and injectable formulation pharmacokinetics.

Key Clinical Trials

Hanna M, Thipphawong J; 118 Study Group. A randomized, double-blind comparison of OROS hydromorphone and controlled-release morphine for the control of chronic cancer pain. BMC Palliat Care. 2008;7:17. doi:10.1186/1472-684X-7-17 Pivotal RCT comparing once-daily ER hydromorphone with CR morphine in cancer pain, demonstrating equivalent efficacy.
Palangio M, Northfelt DW, Portenoy RK, et al. Dose conversion and titration with a novel, once-daily, OROS osmotic technology, extended-release hydromorphone formulation in the treatment of chronic malignant or nonmalignant pain. J Pain Symptom Manage. 2002;23(5):355–368. doi:10.1016/S0885-3924(02)00385-8 Key conversion and titration study establishing the 50% starting dose recommendation for ER formulation.
Inoue S, Saito Y, Tsuneto S, et al. A randomized, double-blind study comparing the efficacy and safety of extended-release hydromorphone with extended-release oxycodone in Japanese patients with cancer pain (EXHEAL). J Pain Res. 2020;13:1859–1868. doi:10.2147/JPR.S254038 The EXHEAL trial demonstrating equivalent efficacy and similar adverse event profiles between ER hydromorphone and ER oxycodone in cancer pain.

Guidelines

Dowell D, Ragan KR, Jones CM, Baldwin GT, Chou R. CDC Clinical Practice Guideline for Prescribing Opioids for Pain — United States, 2022. MMWR Recomm Rep. 2022;71(RR-3):1–95. doi:10.15585/mmwr.rr7103a1 Current CDC guideline on opioid prescribing for acute, subacute, and chronic pain; informs risk assessment and monitoring recommendations.
Fallon M, Giusti R, Aielli F, et al. Management of cancer pain in adult patients: ESMO Clinical Practice Guidelines. Ann Oncol. 2018;29(Suppl 4):iv166–iv191. doi:10.1093/annonc/mdy152 European guideline positioning hydromorphone as a step III opioid for cancer pain alongside morphine and oxycodone.

Mechanistic / Basic Science

Smith HS. Opioid metabolism. Mayo Clin Proc. 2009;84(7):613–624. doi:10.4065/84.7.613 Comprehensive review of opioid metabolism pathways; details UGT2B7-mediated glucuronidation of hydromorphone and H3G neuroexcitatory potential.
Wright AWE, Mather LE, Smith MT. Hydromorphone-3-glucuronide: a more potent neuro-excitant than its structural analogue, morphine-3-glucuronide. Life Sci. 2001;69(4):409–420. doi:10.1016/S0024-3205(01)01133-X Foundational study demonstrating neuroexcitatory properties of H3G metabolite, relevant to renal impairment dosing cautions.

Pharmacokinetics / Special Populations

Vallner JJ, Stewart JT, Kotzan JA, Kirsten EB, Honigberg IL. Pharmacokinetics and bioavailability of hydromorphone following intravenous and oral administration to human subjects. J Clin Pharmacol. 1981;21(4):152–156. doi:10.1002/j.1552-4604.1981.tb05693.x Early human PK study establishing oral bioavailability, volume of distribution, and elimination half-life parameters.
Rodieux F, Vutskits L, Posfay-Barbe KM, Habre W, Piguet V, Desmeules JA, Samer CF. Hydromorphone prescription for pain in children — what place in clinical practice? Front Pediatr. 2022;10:842454. doi:10.3389/fped.2022.842454 Review of hydromorphone pharmacokinetics in paediatric populations, including UGT2B7 maturation and renal clearance considerations.
Durnin C, Hind ID, Ghani SP, Yates DB, Molz KH. Pharmacokinetics of oral immediate-release hydromorphone (Dilaudid IR) in subjects with moderate hepatic impairment. Proc West Pharmacol Soc. 2001;44:83–84. PK study in hepatic impairment demonstrating increased Cmax and AUC, supporting dose reduction recommendations.