Morphine
Classification
high alert medication
controlled and targeted substance
Opioid analgesic
Indications
PCP: Pain management in palliative or end-of-life emergencies
ACP: Analgesia
ACP: Symptom relief in palliative or end-of-life patients with pain or shortness of breath
Morphine should be used secondary to fentanyl in long transfers or for protracted extrication events.
Contraindications
- Known hypersensitivity to morphine or other opioid analgesics
- Head injury with altered LOC (GCS < 9)
- Hypotension (adult SBP < 90 mmHg; children under 12 SBP < 70 mmHg)
- Respiratory depression (adults < 10 breaths/minute; children under 12 < 20 breaths/minute)
Cautions
- Convulsive disorderes
- Cranial injuries
- Respiratory insufficiency, including asthma, COPD, and upper airway obstruction
- Cardiac arrhythmias
- Reduced blood volume (hypovolemia)
Adult dosages
Dosing for Morphine is based on opioid-naive patients. For patients identified as not opioid-naive, consider consultation with CliniCall for additional analgesia planning support.
PCP: Pain management in palliative emergencies or end-of-life patients
- ☎️ Mandatory CliniCall or palliative team consultation to discuss dosing strategies
- Subcutaneous
- 2.5 mg - 5 mg every 10-30 minutes, as required, based on blood pressure (SBP > 100 mmHg), or as per CliniCall or palliative team care plan
- Maximum cumulative dose 20 mg
ACP: Analgesia
- Intravenous
- 2.5 mg - 5 mg prn
- Consider for use in longer transport times
ACP: Symptom relief in palliative or end-of-life patients with pain or shortness of breath
- ☎️ Mandatory CliniCall or palliative team consultation to discuss dosing strategies
- Subcutaneous
- 2.5 mg - 5 mg
- May repeat every 10-30 minutes as required based on blood pressure (SBP > 100 mmHg) or as per CliniCall or palliative team care plan
Pediatric Considerations And Dosing
ACP:
- Intravenous
- Administer one dose initially (0.05 mg/kg). May repeat after 5 minute interval as required for pain control. The dose, up to a cumulative 0.1 mg/kg, can be repeated after two hours.
Table 1. Subcutaneous dosing (palliative pediatric)
|
Age |
Weight (kg) |
Dose (0.05 mg/kg) |
Volume to give (mL) of undiluted morphine* |
Dosing interval |
|
1 |
10 |
0.5 mg |
0.05 mL |
5 minutes |
|
2 |
12 |
0.6 mg |
0.06 mL |
5 minutes |
|
3 |
15 |
0.75 mg |
0.08 mL |
5 minutes |
|
4 |
18 |
0.9 mg |
0.09 mL |
5 minutes |
|
6 |
20 |
1 mg |
0.1 mL |
5 minutes |
|
8 |
25 |
1.25 mg |
0.13 mL |
5 minutes |
|
10 |
30 |
1.5 mg |
0.15 mL |
5 minutes |
|
12 |
40 |
2 mg |
0.2 mL |
5 minutes |
Table 2. Intramuscular (Pediatrics)
|
Age |
Weight (kg) |
Dose (0.1 mg/kg) |
Volume to give (mL) of undiluted morphine* |
|
1 |
10 |
1 mg |
0.1 mL |
|
2 |
12 |
1.2 mg |
0.12 mL |
|
3 |
15 |
1.5 mg |
0.15 mL |
|
4 |
18 |
1.8 mg |
0.18 mL |
|
6 |
20 |
2 mg |
0.2 mL |
|
8 |
25 |
2.5 mg |
0.25 mL |
|
10 |
30 |
3 mg |
0.3 mL |
|
12 |
40 |
4 mg |
0.4 mL |
*Based on Morphine 10 mg/mL concentration (undiluted)
Table 3. Intravenous (Pediatrics)
|
Age |
Weight (kg) |
Initial dose (0.05 mg/kg) |
Volume to give* (mL) |
Dosing interval (once) |
Repeat dose (0.05 mg/kg) |
Diluted volume to give*(mL) |
MAX Cumulative Dose (q 2-4 hours)** |
|
1 |
10 |
0.5 mg |
0.5 mL |
5 minutes |
0.5 mg |
0.5 mL |
2 mg |
|
2 |
12 |
0.6 mg |
0.6 mL |
5 minutes |
0.6 mg |
0.6 mL |
4 mg |
|
3 |
15 |
0.75 mg |
0.75 mL |
5 minutes |
0.75 mg |
0.75 mL |
4 mg |
|
4 |
18 |
0.9 mg |
0.9 mL |
5 minutes |
0.9 mg |
0.9 mL |
4 mg |
|
6 |
20 |
1 mg |
1 mL |
5 minutes |
1 mg |
1 mL |
4 mg |
|
8 |
25 |
1.25 mg |
1.25 mL |
5 minutes |
1.25 mg |
1.25 mL |
8 mg |
|
10 |
30 |
1.5 mg |
1.5 mL |
5 minutes |
1.5 mg |
1.5 mL |
8 mg |
|
12 |
40 |
2 mg |
2 mL |
5 minutes |
2 mg |
2 mL |
10 mg |
How Supplied
Ampoule: 10 mg in 1 mL ampoule
Mechanism Of Action
Binds to opioid receptors in the CNS (primarily mu receptors) causing inhibition of ascending pain pathways, altering the perception of and response to pain and producing generalized CNS depression.
Pharmacokinetics
Intramuscular / subcutaneous:
- Onset: 10 minutes
- Peak: 20-60 minutes (variable)
- Duration: 2-4 hours
Intravenous:
- Onset: 5-10 minutes
- Peak: 20 minutes
- Duration: 2-4 hours
Adverse Effects
- Drowsiness, dizziness, sedation, agitation, euphoria
- Respiratory depression and apnea
- Profound hypotension (may be increased with rapid IV injection), bradycardia
- Nausea, vomiting, constipation
- Pinpoint pupils
- Repeated subcutaneous administration may cause local tissue irritation
- Pseudoallergic reactions (itch, rash) may occur due to direct stimulation of histamine release (anaphylaxis is rare)
Overdose
Provide airway management and ventilatory support. Consider the use of naloxone to reverse opioid intoxication. Naloxone should be used judiciously in patients on long-term opioid therapy to avoid precipitating acute withdrawal syndrome.
See Naloxone guideline.
Drug Interactions
Morphine may enhance respiratory and circulatory depression if used in combination with other opioids, sedatives such as benzodiazepines, phenothiazines, anesthetics, or alcohol.
Do not use morphine in patients taking monoamine oxidase inhibitors (MAOIs) or within 14 days of MAOI discontinuation.