What is the recommended dosage of morphine (opioid) for hospice patients?

Morphine Dosing in Hospice Care

For hospice patients, morphine should be initiated at 2-5 mg orally every 4 hours for opioid-naïve patients, with titration to effect and no specified dose limit. 1, 2

Initial Dosing Strategy

Opioid-Naïve Patients:

• Start with 2-5 mg oral morphine every 4 hours 2
• For intravenous administration: 2 mg IV morphine 1
• Provide the same dose for breakthrough pain 1

Previously on Weak Opioids:

• Start with 5-10 mg oral morphine every 4 hours 1
• For intravenous administration: 2-10 mg IV morphine 1

Route of Administration

The optimal route is oral when possible 1:

• Oral administration: First-line approach
• Intravenous administration: For patients with poor peripheral circulation
• Subcutaneous administration: Potency ratio of oral to subcutaneous is 1:2 2
• Rectal administration: Same bioavailability as oral (1:1 ratio) 2

Dosing Schedule and Formulations

Immediate Release (IR) Formulation:

• Use for initial titration 2
• Administer every 4 hours 1
• Peak plasma concentration: 0.25-1.0 hours 1
• Duration of analgesia: 4 hours 1

Controlled Release (CR) Formulation:

• Use after stabilization on immediate release 2
• Administer every 12 hours 1
• Peak plasma concentration: 2-4 hours 1
• Duration of analgesia: 12 hours 1

Dose Titration

1. Assess efficacy and side effects:

   • Every 60 minutes for oral administration 1
   • Every 15 minutes for IV administration 1

2. If pain persists:

   • Increase dose by 25-50% every 24 hours 2
   • If patient requires more than 4 breakthrough doses in 24 hours, increase the regular dose 2

3. No upper dose limit - titrate to symptom control 1

Breakthrough Pain Management

• For patients on immediate release: Use same dose as regular 4-hourly dose 2
• For patients on controlled release: Use one-third of the 12-hourly dose 1, 2
• For nighttime coverage: Double the regular dose at bedtime for patients on 4-hourly regimen 1

Special Considerations

Renal Impairment:

• For severe renal impairment (eGFR <30 mL/min): Reduce dose by 50-75% and extend dosing interval to 6-8 hours 2
• Consider alternative opioids like fentanyl or buprenorphine 2

Elderly Patients:

• Start at lower end of dosing range 2
• Consider slower titration 2
• Monitor closely for side effects 2

Managing Side Effects

• Constipation: Always prescribe prophylactic laxatives (stimulant laxative with or without stool softener) 1, 2
• Nausea/Vomiting: Prescribe prophylactic antiemetics for the first few days 2
• Sedation: Usually resolves within a few days of stable dosing 1

Important Caveats

• No evidence that high-dose morphine shortens life expectancy in hospice patients 3, 4
• Steady state is reached within 24 hours after starting treatment or dose adjustment 1
• Studies show that over 90% of patients can achieve adequate pain control with proper titration 5
• Daytime drowsiness and mental clouding commonly occur at the start of treatment but typically resolve within a few days 1

Remember that morphine dosing in hospice should be guided by the patient's pain level and response to treatment, with no arbitrary upper limit. The goal is to achieve comfort while minimizing side effects.