What is the dosage of morphine (opioid analgesic) for dyspnea (air hunger)?

From the Guidelines

For managing air hunger, morphine is typically administered at a starting dose of 2.5 to 5 mg intravenously or subcutaneously every 4 hours as needed, or 5 to 10 mg orally every 4 hours, as recommended by the most recent and highest quality study 1.

Key Considerations

• The dose can be titrated upward based on patient response and symptom relief, with a maximum of 30 mg/24 h of oral morphine (or equivalent dose of other opioid) if appropriate 1.
• For patients already on opioids, a dose increase of 25-50% may be necessary 1.
• Continuous infusions may be used in severe cases, starting at 0.5-1 mg/hour after initial bolus dosing.
• Morphine works by decreasing respiratory drive and altering the perception of breathlessness in the brain, which helps relieve the distressing sensation of air hunger without necessarily compromising respiratory function.

Important Side Effects and Precautions

• Side effects to monitor include constipation, nausea, sedation, and respiratory depression, though the latter is less common when morphine is appropriately dosed for dyspnea 1.
• Prophylactic stool softeners and anti-emetics should be considered.
• In elderly patients or those with renal impairment, lower starting doses and careful monitoring are recommended, as morphine should be avoided in patients with severe renal insufficiency 1.
• Alternative opioids like hydromorphone or oxycodone may be considered if morphine is not tolerated 1.

Clinical Context

• The use of opioids for dyspnea is supported by several studies, including a Cochrane review, which found that opioids can provide significant relief for patients with dyspnea 1.
• The "principle of double effect" addresses the potential for harm by use of opioids in palliative care, and health care providers should titrate the dose of opioid to its effect in relieving dyspnea 1.

From the Research

Dosage of Morphine for Dyspnea

• The dosage of morphine for dyspnea varies depending on the patient's condition and the severity of the dyspnea 2, 3, 4, 5, 6.
• A low starting dose of 1.0 mg morphine, immediate release, is recommended for patients with refractory dyspnea in advanced COPD 3.
• The dosage can be titrated to achieve the lowest effective dose based on whether dyspnea relief has been achieved and whether any side effects have developed 3.
• In a laboratory study, a moderate morphine dose of 0.07 mg/kg produced substantial relief of laboratory dyspnea 4.
• In a case series study, the final dose of oral morphine equivalents was 20.1 ± 8.1 mg/d (range: 5-36 mg) for patients with terminally ill noncancer disease 6.

Administration Route

• Morphine can be administered intravenously, subcutaneously, orally, or via inhalation 2, 3, 4, 5, 6.
• Continuous infusions, suppository, and oral administration are also used 6.

Efficacy and Safety

• Low-dose opioid administration has been shown to be effective in reducing dyspnea in patients with acute respiratory failure, advanced COPD, and terminally ill noncancer disease 2, 3, 4, 6.
• The treatment has been demonstrated to be safe, with no severe adverse events reported in several studies 3, 6.