Dyspnea – shortness of breath

Opioids are the drugs of choice for dyspnea in advanced disease.

Adjuvants and other therapies should always be considered.

Essential opioid principles

There are 12 essentials to know when prescribing opioids:

  1. Opioids are the drug of choice for both pain and dyspnea in advanced disease.
  2. Patients with addiction should have pain/dyspnea treated — use long acting opioid medications, limited breakthroughs, small amount dispensed frequently.
  3. Opioids are safe in cardiopulmonary disease, but start low go slow.
  4. Persistent symptoms require regular dosing, i.e. short-acting opioid q4 hours.
  5. Not all opioids are the same, and inter-individual analgesia/side effects vary widely.
  6. Opioids with few or no active metabolites are preferred for those with renal failure or frailty.
  7. Always order breakthrough with regular dosing: 10% of total daily opioid dose q1h prn. Recalculate breakthrough dose when regular dose is changed.
  8. If 3 or more breakthroughs used in the last 24 hours, increase the regular dose.
  9. Titrate dose to the best symptom control with the fewest side effects.
  10. When you prescribe an opioid, prescribe a laxative.
  11. If side effects are intolerable, consider rotating opioid.
  12. Educate patient/family about control of symptoms and opioid safety.

Talk tip: “Controlling shortness of breath helps you to have better quality of life.”
Talk tip: ”These medications can always be increased if you have more shortness of breath. They do not lose effectiveness over time.”
Talk tip: ”Our goal is to prevent shortness of breath, so take the medication as directed even if you don’t have shortness of breath at the time.”

Opioid Equianalgesic Table

Name PO dose
Tylenol #3 (codeine 30mg/acetaminophen 325mg) 2 tablets
Morphine 10mg
Hydromorphone 2mg
Oxycodone 7.5mg
Fentanyl – see note below

Morphine to fentanyl

Fentanyl 25mcg/hr patch =
50mg morphine/day orally

Fentanyl 25mcg/hr patch =
100mg morphine/day orally in CRF and frail older adult

Breakthrough dose
Calculate breakthrough dose based on morphine equivalents of the patch. Lowest dose patch=12mcg/hr

Opioid dosing

Opioid Starting p.o. dose Oral/ SC dose Starting p.o dose frail,
Active metabolites
Tylenol 3 avoid 2 tabs/ n/a avoid +++
Morphine 5-10 mg q4h 10mg/5mg 2.5-5mg q4hr +++
Hydromorphone 1-2mg q4h 2mg/1mg .5-1mg q4h ++
Oxycodone 5-10mg q4h 7.5mg/ n/a 2.5-5mg q4h 0
Fentanyl transdermal see footnote see footnote see footnote 0
(consult POCT)
2-5mg q8h 1mg/0.5mg 1mg q12h 0

*Tap the orange + symbol to see additional information


Opioid naive: patient has NOT had 5 days of continuous opioid exposure (i.e. short-acting q4hr po,sc; long-acting q12hr; transdermal)

Fentanyl transdermal patch NOT recommended for opioid-naive patients. Previous opioid must be continued for first 12 hours of Fentanyl patch as onset delayed. See Opioid Equianalgesic Table for conversion from morphine to Fentanyl.

Morphine conversion factor:see opioid rotation

Methadone: Need special license to prescribe. Variable half life and dosing.

Opioid Calculations

Calculating breakthrough dose

10% of the total daily regular opioid dose q1h prn

Morphine 50mg q4hr total daily dose 50×6=300mg. 300/10=30mg q1hr prn

Review + calc new dose

Add 24 hour/total regular dose+total breakthroughs used=total daily opioid dose. Divide this by dosing intervals. This is new regular dose. Recalculate breakthrough dose.

Hydromorphone 12mg q4h, with 4 breakthroughs of 8mg q1h

Total daily opioid dose

New dosing
104/6=16mg q4hr with breakthrough of of 10mg q1hr prn

Switching to sustained release (SR)

Titrate short-acting to optimal dose

Total daily dose
Add total regular dose+breakthroughs (if used)

Total daily dose /2
Opioid SR q12hours

Note about younger patients
They metabolize rapidly and may require q8dosing.

Opioid rotation

Add total regular dose+ breakthroughs (if used)=total daily dose. Total daily dose X morphine conversion factor=total daily morphine equivalents.

Total daily new opioid dose
Daily morphine equivalents/conversion factor to new opioid: reduce 25-50% in case of tolerance to previous opioid. Divide by dosing interval.

Morphine conversion factor

  • morphine 10mg
  • hydromorphone 2mg
  • oxycodone 7.5mg
  • Tylenol #3 – 2 tabs

Tylenol 3 12tabs/day=60mg morphine equivalents per day=12mg of hydromorphone per day=9mg hydromorphone per day (reduced for tolerance)=1.5 mg hydromorphone po q4hr, hydromorphone 1mg q1hr prn for breakthrough.

Oral to parenteral

Depending on the opioid, may have to rotate to either hydromorphone or morphine for sc.

Total daily oral dose
Add up regular oral doses + breakthroughs (if used). Total daily oral dose/2=total parenteral dose.

Morphine SR 120mg po q12hx2=240mg total daily morphine dose po=120mg total parenteral morphine dose=20mg s.c. q4h regular, morphine 12mg sc q1hr prn for breakthrough.

Opioid side effects


Tolerance develops in 2-5 days. If not, rotate opioid. If symptom controlled, reduce dose.

Talk tip: “You may be drowsy for the first two days, but it should clear.”


Common in first week.


  • 10mg qid


  • 0.5mg bid

Rotate opioid if persists.


Constipation always occurs with opioid use.

Stimulant laxative (senna) +/- osmotic laxative (PEG, lactulose).

Opioid-induced neurotoxicity

Spectrum of neurotoxicity starting with reduced LOC, myoclonus, hallucinations, delirium and rarely seizures.

Rotate opioid, consider hydration, treat concurrent infection.


Consider rotation if persists.

Respiratory depression secondary to opioids

Rare with appropriate dosing. Respiratory depression due to opioids = increased pCO2 + decreased pO2 + low respiratory rate. Assess O2 saturation, respiratory rate and signs of hypoventilation. Differential diagnosis: sedation from drugs (benzodiazepines or neuroleptics), hypoglycemia, head trauma, exhaustion, actively dying.

Mild – moderate: reduce/review dosing of all sedating medications

Severe: Risk of severe pain, aspiration and opioid withdrawal with full dose naloxone. Dilute dose naloxone: dilute 1ml (0.4mg/ml) naloxone in 9ml saline, slow IV push (0.5-1ml q2min) Goal of naloxone is to improve ventilation. Partial reversal of respiratory disturbance by naloxone does not confirm opioid as the primary cause particularly if problems develop during stable opioid dosing.



  • 5-10mg po/sc tid
  • frail older adults: 2.5-5mg po/sc tid


  • no evidence that they reduce dyspnea
  • may cause delirium in frail older adults


  • little evidence that it relieves dyspnea even in hypoxic patients


  • if strong anxiety component, consider anxiolytics

Other therapies


  • stimulates trigeminal V2 branch and reduces dyspnea
  • direct gentle breeze across face

Calm presence

  • a calm provider is essential
  • family distress can exacerbate dyspnea
  • meditation/relaxation may help


  • 45-60 degrees upright, arms away from sides

Talk tip: “Many people are fearful of dying when they feel short of breath. Do you feel like this?”

Patient will benefit from a plan for severe dyspnea episodes and discussion that they will not die gasping for breath as dyspnea can be managed.

Contact us: severe dyspnea in advanced illness is an emergency.

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