Opioid use disorder, maintenance treatment: Note: Individualize dosing regimen based on patient-specific factors (eg, comorbidities, severity of pain, concomitant medications, cachexia, general condition, degree of opioid experience/tolerance) and titrate to patient-specific treatment goals. Patients may receive supplemental oral opioid agonist therapy or transition to methadone to minimize withdrawal symptoms between doses. Patients may administer the injections, however, patients must be supervised by health care providers experienced in the treatment of severe opioid use disorder and trained in the administration of injectable opioid agonist therapy; patients must be monitored for 15 to 30 minutes after diamorphine administration for signs of withdrawal, overdose, respiratory depression, or sedation in health care settings where emergency naloxone and resuscitation equipment is available and cardiopulmonary resuscitation can be performed.
IM, IV: Initiate therapy over several days and titrate to response (see "Example Initiation Regimens" below).
Example initiation regimens:
Initiation:
Two Doses per Day (CRISM 2019)
Day 1:
Dose 1: IM, IV: 30 mg, then observe for 15 minutes; if no intoxication symptoms, administer 60 mg based on clinical judgement and discussion with patient; observe for 15 minutes. Administer next dose in 3 to 12 hours. Total possible dose = 90 mg.
Dose 2: IM, IV: If dose 1 is well tolerated, administer 90 mg and observe for 15 minutes; if no intoxication symptoms, administer 60 mg based on clinical judgement and discussion with patient; observe for 15 minutes. Administer next dose the following day. Total possible dose = 150 mg.
Day 2:
Dose 1: IM, IV: Administer 100 mg and observe for 15 minutes; if no intoxication symptoms, administer 60 mg based on clinical judgement and discussion with patient; observe for 15 minutes. Administer next dose in 3 to 12 hours. Total possible dose = 160 mg.
Dose 2: IM, IV: Administer 160 mg and observe for 15 minutes; if no intoxication symptoms, administer 40 mg based on clinical judgement and discussion with patient; observe for 15 minutes. Administer next dose the following day. Total possible dose = 200 mg.
Day 3: Administer maximum tolerated single dose given during day 2 every 12 hours; observe for 15 minutes following every dose.
Three Doses per Day (Oviedo-Joekes 2016 ; Palis 2018; CRISM 2019 )
Day 1:
Dose 1: IM, IV: 15 mg, then observe for 15 minutes; if no intoxication symptoms, administer 30 mg based on clinical judgement and discussion with patient; observe for 15 to 30 minutes. Administer next dose in 3 to 8 hours. Total possible dose = 45 mg.
Dose 2: IM, IV: If dose 1 is well tolerated, administer 45 mg and observe for 15 to 30 minutes; if no intoxication symptoms, administer 30 mg based on clinical judgement and discussion with patient; observe for 15 to 30 minutes. Administer next dose in 3 to 8 hours. Total possible dose = 75 mg.
Dose 3: IM, IV: If previous doses are well-tolerated, administer 75 mg and observe for 15 to 30 minutes; if no intoxication symptoms, administer 30 mg based on clinical judgement and discussion with patient; observe for 15 to 30 minutes. Administer next dose the following day. Total possible dose = 105 mg.
Day 2:
Dose 1: IM, IV: Administer 40% of total daily dose at day 1 (up to a total of 90 mg if all doses on day 1 were tolerated) and observe for 15 to 30 minutes; if no intoxication symptoms, administer 30 mg based on clinical judgement and discussion with patient; observe for 15 to 30 minutes. Administer next dose in 3 to 8 hours. Total possible dose = 120 mg.
Dose 2: IM, IV: Administer maximum tolerated amount of dose 1 (up to 120 mg) and observe for 15 to 30 minutes; if no intoxication symptoms, administer 30 mg based on clinical judgement and discussion with patient; observe for 15 to 30 minutes. Administer next dose in 3 to 8 hours. Total possible dose = 150 mg.
Dose 3: IM, IV: Administer maximum tolerated amount of dose 2 (up to 150 mg) and observe for 15 to 30 minutes; if no intoxication symptoms, administer 30 mg based on clinical judgement and discussion with patient; observe for 15 to 30 minutes. Administer next dose the following day. Total possible dose = 180 mg.
Day 3: Administer maximum tolerated single dose given during day 2 every 8 hours; observe for 15 to 30 minutes following every dose.
Maintenance: IM, IV: Adjust dosage once a week based on response and tolerability. Maximum single dose: 400 mg; maximum daily dose: 1 g/day.
Missed dose: If treatment is interrupted, re-initiation of dose titration may be needed, starting at a decreased dose.
Conversion to oral methadone: During transition to or from diamorphine, ensure dose of methadone is properly calculated so patient receives the same degree of saturation of opioid receptors.
Discontinuation of therapy: When indicated, gradually taper under medical supervision.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
CrCl >50 mL/minute: No dosage adjustment necessary.
CrCl 20 to 50 mL/minute: Administer 75% of usual initial dose; titrate cautiously to response.
CrCl 10 to 20 mL/minute: Administer 50% of usual initial dose; titrate cautiously to response.
CrCl <10 mL/minute or hemodialysis: Use not recommended.
Mild impairment: There are no dosage adjustments provided in the manufacturer's labeling.
Moderate impairment: There are no dosage adjustments provided in the manufacturer's labeling; use with caution. Initiate treatment at the lowest possible dose and titrate slowly with extended dosing intervals.
Severe impairment: Use is not recommended.
Initiate at a lower dose and slowly titrate to effect.
Yes
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution Reconstituted, Injection, as hydrochloride:
Generic: 200 mg (1 ea); 5000 mg (1 ea)
Not available in the United States.
C-I
Only available through controlled distribution.
IM, IV: May administer by supervised self-injection IM or IV; do not inject into the jugular or femoral vein. Use proper injection techniques to minimize risk of infection.
Note: Not approved in the United States.
Opioid use disorder, maintenance treatment: Maintenance treatment of opioid use disorder in adult patients who use injectable opioids and have failed previous attempts at opioid agonist therapy (including methadone); in conjunction with an individualized, comprehensive, opioid dependence treatment program (eg, medical, psychological, social support).
Diamorphine may be confused with morphine or hydromorphone.
Diamorphine may be confused with Diamox brand name for acetazolamide (various countries), Dimorf brand name for morphine (Brazil), and Duramorph brand name for morphine (United States).
This medication is in a class the Institute of Safe Medication Practices (ISMP) includes among its list of drug classes that have heightened risk of causing significant patient harm when used in error.
ALERT: Canadian Boxed Warning: Health Canada-approved labeling includes a boxed warning. See "Warnings/Precautions" section for a concise summary of this information. For verbatim wording of the boxed warning, consult the product labeling.
Significant differences exist between dosing diamorphine and morphine or diamorphine oral and IV dosing. Use caution when converting from one drug to the other or from one route of administration to another.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Adverse reactions reported in adults and may include concomitant methadone.
>10%:
Dermatologic: Skin rash (4% to 43%)
Local: Application-site pruritus (30%), injection-site reaction (43%; including injection-site pruritus and urticaria at injection site)
1% to 10%: Nervous system: Drowsiness (9%), seizure (3% to 5%)
Frequency not defined:
Cardiovascular: Circulatory depression, shock
Gastrointestinal: Constipation, decreased gastrointestinal motility, nausea, vomiting
Hypersensitivity: Hypersensitivity reaction (including anaphylaxis, local hypersensitivity reaction, and severe hypersensitivity reaction)
Nervous system: Drug abuse, opioid dependence
Postmarketing:
Cardiovascular: Peripheral edema, presyncope, syncope
Dermatologic: Pruritus, urticaria
Endocrine & metabolic: Altered hormone level (decreased luteinizing hormone and follicle stimulating hormone), amenorrhea, increased serum glucose, increased serum prolactin, loss of libido
Gastrointestinal: Biliary colic, decreased appetite, delayed gastric emptying, paralytic ileus
Genitourinary: Urinary hesitancy, urinary retention
Hepatic: Increased liver enzymes
Nervous system: Agitation, anxiety, asthenia, chills, confusion, disorientation, dysphoria, emotional lability, euphoria, fatigue, feeling abnormal, hallucination, increased intracranial pressure, lethargy, malaise, myoclonus, neonatal withdrawal, nervousness, nightmares, paresthesia, serotonin syndrome, tremor, withdrawal syndrome
Neuromuscular & skeletal: Dyskinesia, laryngospasm
Ophthalmic: Blurred vision, diplopia, miosis, nystagmus disorder, visual impairment
Respiratory: Bronchospasm, dyspnea, respiratory depression
Miscellaneous: Drug tolerance
Hypersensitivity to diamorphine, other opioid agonists, or any component of the formulation; patients without opioid use disorder and who are not currently taking high doses or high concentrations of opioids; known or suspected mechanical GI obstruction (eg, bowel obstruction, strictures); diseases/conditions that affect bowel transit (eg, ileus of any type); acute or severe bronchial asthma; chronic obstructive airway; status asthmaticus; acute respiratory depression; elevated carbon dioxide levels; cor pulmonale; acute alcohol use disorder; delirium tremens; seizures; severe CNS depression; increased cerebrospinal fluid; increased intracranial pressure; head injury; concomitant use with monoamine oxidase inhibitors or within 2 weeks of their discontinuation; patients with signs of intoxication, including due to centrally acting sedatives, stimulants, or other acute condition that would increase the risk of adverse effects; bipolar disorder, schizophrenia, or other psychiatric disorders with active psychotic symptoms refractory to medical management.
Concerns related to adverse effects:
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery, driving).
• Hypersensitivity: Generalized and localized hypersensitivity reactions may occur at the injection site.
• Hypotension: May cause severe hypotension (including orthostatic hypotension and syncope); use with caution in patients with hypovolemia, cardiovascular disease (including acute myocardial infarction), circulatory shock, or drugs that may exaggerate hypotensive effects (including phenothiazines or general anesthetics). Avoid use in patients with circulatory shock. Avoid rapid IV injection.
• Respiratory depression: [Canadian Boxed Warning]: Serious, life-threatening, or fatal respiratory depression may occur. Monitor closely for respiratory depression, especially during initiation or dose escalation. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids. Patients and caregivers should be educated on how to recognize respiratory depression and the importance of getting emergency assistance immediately (eg, calling 911) in the event of known or suspected overdose.
• Serotonin syndrome: May occur with concomitant use of serotonergic agents (eg, selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, triptans, tricyclic antidepressants [TCAs]), lithium, St John's wort, agents that impair metabolism of serotonin (eg, monoamine oxidase inhibitors), or agents that impair metabolism of tramadol (eg, CYP2D6 and 3A4 inhibitors). Symptoms may include mental status changes (eg, agitation, hallucinations, coma); autonomic instability (eg, tachycardia, labile BP, hyperthermia); neuromuscular changes (eg, hyperreflexia, incoordination); and/or GI symptoms (eg, nausea, vomiting, diarrhea).
Disease-related concerns:
• Abdominal conditions: May obscure diagnosis or clinical course of patients with acute abdominal conditions.
• Adrenocortical insufficiency: Use with caution in patients with adrenal insufficiency, including Addison disease. Long-term opioid use may cause secondary hypogonadism, which may lead to sexual dysfunction, infertility, mood disorders, and osteoporosis (Brennan 2013).
• Biliary tract impairment: Use with caution in patients with biliary tract dysfunction or acute pancreatitis; opioids may cause constriction of sphincter of Oddi.
• Coagulation disorders: Use with caution in patients with coagulation disorders.
• Infection: Use with caution in patients with injection-related infections (eg, sepsis, endocarditis, pneumonia, infective osteomyelitis).
• Respiratory disease: Use with caution in patients with decreased respiratory reserve, hypoxia, hypercarbia, or preexisting respiratory depression, particularly when initiating therapy and titrating therapy; critical respiratory depression may occur, even at therapeutic dosages.
• Seizure disorders: [Canadian Boxed Warning]: Use with caution in patients with seizure disorders or at risk for seizures (eg, head trauma, metabolic disorders, alcohol and drug withdrawal, CNS infections, concurrent use with other medications that reduce seizure threshold).
• Sleep-related disorders: Opioid use increases the risk for sleep-related disorders (eg, central sleep apnea [CSA], hypoxemia) in a dose-dependent fashion. Use with caution for chronic pain and titrate dosage cautiously in patients with risk factors for sleep-disordered breathing (eg, heart failure, obesity). Consider dose reduction in patients presenting with CSA. Avoid opioids in patients with moderate to severe sleep-disordered breathing (CDC [Dowell 2016]).
• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.
Concurrent drug therapy issues:
• Benzodiazepines or other CNS depressants: [Canadian Boxed Warning]: Concomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in profound sedation, somnolence, respiratory depression, coma, and death. Antidepressants (eg, TCAs) may increase risk of arrhythmias, seizures, and affect thyroid levels. Reserve concomitant prescribing of morphine and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate. Limit dosage and durations to the minimum required and follow patients for signs and symptoms of respiratory depression and sedation. Consider prescribing naloxone for emergency treatment of opioid overdose in patients taking benzodiazepines or other CNS depressants concomitantly with opioids.
• Ethanol use: Patients should not consume alcoholic beverages or medication containing ethanol while taking diamorphine; ethanol may increase plasma levels, resulting in a potentially fatal overdose.
Special populations:
• Cachectic or debilitated patients: Use with caution in cachectic or debilitated patients; there is a greater potential for critical respiratory depression, even at therapeutic dosages. Consider the use of alternative nonopioid analgesics in these patients.
• Neonates: Neonatal withdrawal syndrome: [Canadian Boxed Warning]: Prolonged maternal use of opioids during pregnancy can cause neonatal withdrawal syndrome in the newborn, which may be life-threatening. Signs and symptoms include irritability, hyperactivity, abnormal sleep pattern, high-pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. Onset, duration, and severity depend on the drug used, duration of use, maternal dose, and rate of drug elimination by the newborn.
• Older patients: Use with caution in older patients; may be more sensitive to adverse effects, including life-threatening respiratory depression.
Other warnings/precautions:
• Abrupt discontinuation/withdrawal: Abrupt discontinuation or missed doses in patients who are physically dependent on opioids has been associated with serious withdrawal symptoms, uncontrolled pain, attempts to find other opioids (including illicit), and suicide. Use a collaborative, patient-specific taper schedule that minimizes the risk of withdrawal, considering factors such as current opioid dose, duration of use, type of pain, and physical and psychological factors. Diacetylmorphine interruption may require starting at a decreased dose for patient safety as rapid loss in tolerance may result in increased risk of overdose.
• Abuse/misuse/diversion: [Canadian Boxed Warning]: Diamorphine exposes patients and other users to the risks of addiction, abuse, and misuse, potentially leading to overdose and death. Assess each patient's risk prior to prescribing; monitor all patients regularly for development of these behaviors or conditions. Store securely to avoid theft and diversion.
• Accidental exposure: [Canadian Boxed Warning]: Use care to reduce risk of accidental exposure during reconstitution; ensure all syringes are properly and securely stored.
• Appropriate use: [Canadian Boxed Warning]: For use only in opioid-tolerant patients requiring high concentrations of opioid agonists under a health care provider trained in the treatment of opioid use disorder and the provision of opioid agonist therapy. Initiate treatment slowly. Assess patient to determine readiness to leave the health care setting and ensure safe transportation is available. Do not inject into the jugular or femoral vein; jugular vein thrombosis, deep neck infections, pneumothorax, endocarditis, and sepsis may occur. Should only be administered in facilities equipped and staffed to immediately recognize severe adverse reactions (eg, respiratory depression, seizures); resuscitative equipment, oxygen, naloxone, and other resuscitative drugs should be available for immediate use. Use with caution in patients who cannot safely self-inject medication (eg, poor venous access, poor injection technique).
• Naloxone access: Discuss the availability of naloxone with all patients who are prescribed opioid analgesics, as well as their caregivers, and consider prescribing it to patients who are at increased risk of opioid overdose. These include patients who are also taking benzodiazepines or other CNS depressants, have an opioid use disorder (OUD) (current or history of), or have experienced a previous opioid overdose. Additionally, health care providers should consider prescribing naloxone to patients prescribed medications to treat OUD; patients at risk of opioid overdose, even if they are not taking an opioid analgesic or medication to treat OUD; and patients taking opioids, including methadone or buprenorphine for OUD, if they have household members, including children, or other close contacts at risk for accidental ingestion or opioid overdose. Inform patients and caregivers on options for obtaining naloxone (eg, by prescription, directly from a pharmacist, a community-based program) as permitted by state dispensing and prescribing guidelines. Educate patients and caregivers on how to recognize respiratory depression, proper administration of naloxone, and getting emergency help.
None known.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the Lexicomp drug interactions program by clicking on the “Launch drug interactions program” link above.
Alcohol (Ethyl): May enhance the CNS depressant effect of Diamorphine. Risk X: Avoid combination
Alizapride: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Alvimopan: Opioid Agonists may enhance the adverse/toxic effect of Alvimopan. This is most notable for patients receiving long-term (i.e., more than 7 days) opiates prior to alvimopan initiation. Management: Alvimopan is contraindicated in patients receiving therapeutic doses of opioids for more than 7 consecutive days immediately prior to alvimopan initiation. Risk D: Consider therapy modification
Amphetamines: May enhance the analgesic effect of Opioid Agonists. Risk C: Monitor therapy
Anticholinergic Agents: May enhance the adverse/toxic effect of Opioid Agonists. Specifically, the risk for constipation and urinary retention may be increased with this combination. Risk C: Monitor therapy
Antiplatelet Agents (P2Y12 Inhibitors): Diamorphine may diminish the antiplatelet effect of Antiplatelet Agents (P2Y12 Inhibitors). Diamorphine may decrease the serum concentration of Antiplatelet Agents (P2Y12 Inhibitors). Risk C: Monitor therapy
Azelastine (Nasal): May enhance the CNS depressant effect of CNS Depressants. Risk X: Avoid combination
Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Management: Use caution if coadministering blonanserin and CNS depressants; dose reduction of the other CNS depressant may be required. Strong CNS depressants should not be coadministered with blonanserin. Risk D: Consider therapy modification
Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Bromopride: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Bromperidol: May enhance the CNS depressant effect of CNS Depressants. Risk X: Avoid combination
Cannabinoid-Containing Products: CNS Depressants may enhance the CNS depressant effect of Cannabinoid-Containing Products. Risk C: Monitor therapy
Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Risk D: Consider therapy modification
Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Risk C: Monitor therapy
CNS Depressants: May enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Risk D: Consider therapy modification
Daridorexant: May enhance the CNS depressant effect of CNS Depressants. Management: Dose reduction of daridorexant and/or any other CNS depressant may be necessary. Use of daridorexant with alcohol is not recommended, and the use of daridorexant with any other drug to treat insomnia is not recommended. Risk D: Consider therapy modification
Desmopressin: Opioid Agonists may enhance the hyponatremic effect of Desmopressin. Risk C: Monitor therapy
DexmedeTOMIDine: CNS Depressants may enhance the CNS depressant effect of DexmedeTOMIDine. Management: Monitor for increased CNS depression during coadministration of dexmedetomidine and CNS depressants, and consider dose reductions of either agent to avoid excessive CNS depression. Risk D: Consider therapy modification
Difelikefalin: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Diuretics: Opioid Agonists may enhance the adverse/toxic effect of Diuretics. Opioid Agonists may diminish the therapeutic effect of Diuretics. Risk C: Monitor therapy
Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Risk D: Consider therapy modification
Eluxadoline: Opioid Agonists may enhance the constipating effect of Eluxadoline. Risk X: Avoid combination
Flunarizine: CNS Depressants may enhance the CNS depressant effect of Flunarizine. Risk X: Avoid combination
Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Management: Reduce the dose of CNS depressants when combined with flunitrazepam and monitor patients for evidence of CNS depression (eg, sedation, respiratory depression). Use non-CNS depressant alternatives when available. Risk D: Consider therapy modification
Gastrointestinal Agents (Prokinetic): Opioid Agonists may diminish the therapeutic effect of Gastrointestinal Agents (Prokinetic). Risk C: Monitor therapy
HydrOXYzine: May enhance the CNS depressant effect of CNS Depressants. Management: Consider a decrease in the CNS depressant dose, as appropriate, when used together with hydroxyzine. Increase monitoring of signs/symptoms of CNS depression in any patient receiving hydroxyzine together with another CNS depressant. Risk D: Consider therapy modification
Kava Kava: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Kratom: May enhance the CNS depressant effect of CNS Depressants. Risk X: Avoid combination
Lemborexant: May enhance the CNS depressant effect of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Risk D: Consider therapy modification
Lisuride: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Lofexidine: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce the usual dose of CNS depressants by 50% if starting methotrimeprazine until the dose of methotrimeprazine is stable. Monitor patient closely for evidence of CNS depression. Risk D: Consider therapy modification
Metoclopramide: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Risk C: Monitor therapy
Minocycline (Systemic): May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Monoamine Oxidase Inhibitors: May enhance the adverse/toxic effect of Diamorphine. Risk X: Avoid combination
Nalfurafine: Opioid Agonists may enhance the adverse/toxic effect of Nalfurafine. Opioid Agonists may diminish the therapeutic effect of Nalfurafine. Risk C: Monitor therapy
Nalmefene: May diminish the therapeutic effect of Opioid Agonists. Management: Avoid the concomitant use of oral nalmefene and opioid agonists. Discontinue oral nalmefene 1 week prior to any anticipated use of opioid agonists. If combined, larger doses of opioid agonists will likely be required. Risk D: Consider therapy modification
Naltrexone: May diminish the therapeutic effect of Opioid Agonists. Management: Seek therapeutic alternatives to opioids. See full drug interaction monograph for detailed recommendations. Risk X: Avoid combination
Nirmatrelvir and Ritonavir: May decrease the serum concentration of Diamorphine. Risk C: Monitor therapy
Olopatadine (Nasal): May enhance the CNS depressant effect of CNS Depressants. Risk X: Avoid combination
Opioid Agonists: CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Risk D: Consider therapy modification
Opioids (Mixed Agonist / Antagonist): May diminish the analgesic effect of Opioid Agonists. Management: Seek alternatives to mixed agonist/antagonist opioids in patients receiving pure opioid agonists, and monitor for symptoms of therapeutic failure/high dose requirements (or withdrawal in opioid-dependent patients) if patients receive these combinations. Risk X: Avoid combination
Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Risk X: Avoid combination
Oxitriptan: Diamorphine may enhance the serotonergic effect of Oxitriptan. This could result in serotonin syndrome. Risk X: Avoid combination
Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Risk X: Avoid combination
Oxybate Salt Products: CNS Depressants may enhance the CNS depressant effect of Oxybate Salt Products. Management: Consider alternatives to this combination when possible. If combined, dose reduction or discontinuation of one or more CNS depressants (including the oxybate salt product) should be considered. Interrupt oxybate salt treatment during short-term opioid use Risk D: Consider therapy modification
OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Risk D: Consider therapy modification
Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Risk X: Avoid combination
Pegvisomant: Opioid Agonists may diminish the therapeutic effect of Pegvisomant. Risk C: Monitor therapy
Piribedil: CNS Depressants may enhance the CNS depressant effect of Piribedil. Risk C: Monitor therapy
Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Risk C: Monitor therapy
Procarbazine: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
QuiNIDine: May increase serum concentrations of the active metabolite(s) of Diamorphine. Management: Use caution and reduce the diamorphine dose during coadministration with quinidine. Risk D: Consider therapy modification
Ramosetron: Opioid Agonists may enhance the constipating effect of Ramosetron. Risk C: Monitor therapy
RifAMPin: May decrease serum concentrations of the active metabolite(s) of Diamorphine. Risk C: Monitor therapy
Ritonavir: May decrease the serum concentration of Diamorphine. Risk C: Monitor therapy
Ropeginterferon Alfa-2b: CNS Depressants may enhance the adverse/toxic effect of Ropeginterferon Alfa-2b. Specifically, the risk of neuropsychiatric adverse effects may be increased. Management: Avoid coadministration of ropeginterferon alfa-2b and other CNS depressants. If this combination cannot be avoided, monitor patients for neuropsychiatric adverse effects (eg, depression, suicidal ideation, aggression, mania). Risk D: Consider therapy modification
ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Risk C: Monitor therapy
Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Risk C: Monitor therapy
Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Risk C: Monitor therapy
Samidorphan: May diminish the therapeutic effect of Opioid Agonists. Risk X: Avoid combination
Serotonergic Agents (High Risk): Opioid Agonists may enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Risk C: Monitor therapy
Sincalide: Drugs that Affect Gallbladder Function may diminish the therapeutic effect of Sincalide. Management: Consider discontinuing drugs that may affect gallbladder motility prior to the use of sincalide to stimulate gallbladder contraction. Risk D: Consider therapy modification
Somatostatin Analogs: Opioid Agonists may diminish the analgesic effect of Somatostatin Analogs. Opioid Agonists may enhance the analgesic effect of Somatostatin Analogs. Risk C: Monitor therapy
Succinylcholine: May enhance the bradycardic effect of Opioid Agonists. Risk C: Monitor therapy
Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Risk D: Consider therapy modification
Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Risk X: Avoid combination
Tryptophan: Diamorphine may enhance the serotonergic effect of Tryptophan. This could result in serotonin syndrome. Risk X: Avoid combination
Valerian: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Risk D: Consider therapy modification
Amenorrhea and loss of libido have been reported following diamorphine use. Long-term opioid use and misuse may cause infertility, including erectile dysfunction, decreased sperm motility, menstrual disorders, and amenorrhea, in patients of reproductive potential. Pregnancy testing is recommended prior to initiating therapy for opioid use disorders (SAMHSA 2021).
Opioids cross the placenta.
Prolonged use of opioids during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening. Symptoms of neonatal opioid withdrawal syndrome following opioid exposure may be autonomic (eg, fever, temperature instability), GI (eg, diarrhea, vomiting, poor feeding/weight gain), or neurologic (eg, high-pitched crying, hyperactivity, increased muscle tone, increased wakefulness/abnormal sleep pattern, irritability, sneezing, seizure, tremor, yawning) (Dow 2012; Hudak 2012). The onset and duration of neonatal withdrawal symptoms are dependent upon the specific opioid used, maternal dosing, duration of use, and rate of elimination by the newborn.
Opioids are present in breast milk; the amount of diamorphine in breast milk is not known.
Infants exposed to diamorphine via breast milk are at risk for life-threatening respiratory depression. Consider the potential benefit to the mother and the potential risk to the breastfed infant prior to use in breastfeeding patients.
Monitor for signs of withdrawal, overdose, respiratory depression, and sedation during administration and for 30 minutes following administration; signs of intoxication, withdrawal, and to avoid diversion prior to initiation, during, and after injection; signs of injection-related infections; symptoms of hypotension following initiation or dose titration; signs of serotonin syndrome; signs of misuse, abuse, and addiction.
A potent morphine opiate derivative with CNS depressant effects, increases smooth muscle tone, and causes the release of histamine and catecholamines.
Onset: IV: 0.3 minutes; IM: 5 minutes.
Duration: IV: 1 to 3 hours.
Absorption: IM: 5 minutes diacetylmorphine, metabolite 6-monoacetylmorophine peaks within 6 minutes, and morphine within 17 minutes.
Distribution: IV: 37 ± 16 L; active metabolite: 60 to 100 L.
Protein binding: 20% to 40% to albumin.
Metabolism: Rapidly hydrolyzed to active metabolites 6-monoacetylmorphine (further metabolized to morphine) by serum and liver esterases; some morphine-glucuronides are excreted in the bile and are hydrolyzed into morphine in the colon resulting in enterohepatic recirculation and additional contribution to total bioavailability of morphine.
Bioavailability: IM: 380% ± 157%; ≥3 to 4 times greater than IV administration; metabolite 6-monoacetylmorophine mean 120% ± 30% and morphine 134% ± 54% compared to IV administration.
Half-life elimination: Active metabolites: Terminal: 2 to 6.4 hours.
Time to peak: IM: 5 minutes; active metabolites: 6 to 17 minutes; IV: 0.7 to 5.1 hours; active metabolite: 0.3 minutes.
Excretion: Urine (70%; 55% as conjugated morphine).
