Converting Morphine ER 30 mg BID to Liquid Morphine
Convert morphine ER 30 mg twice daily to liquid morphine 10 mg every 4 hours (6 doses per 24 hours), with an additional 10 mg available every 4 hours as needed for breakthrough pain. 1
Conversion Calculation
- Total daily morphine dose: Morphine ER 30 mg × 2 doses = 60 mg per day 1
- Immediate-release liquid morphine dosing frequency: Every 4 hours for around-the-clock pain control = 6 doses per 24-hour period 1
- Individual dose calculation: 60 mg ÷ 6 doses = 10 mg every 4 hours 1
Alternative Dosing Schedule
- Bedtime double-dose option: Give 20 mg at bedtime to avoid nighttime awakening, reducing the schedule to 5 doses daily (10 mg × 4 doses during the day + 20 mg at bedtime) 1
- More frequent dosing: Some patients may require dosing every 3 hours rather than 4 hours due to individual pharmacokinetics 1
Breakthrough Pain Management
- Prescribe additional liquid morphine for breakthrough pain equal to the 4-hourly scheduled dose (10 mg in this case) 1
- This can be taken as needed between scheduled doses 1
Mandatory Concurrent Prescriptions
Always prescribe a stimulant laxative (senna/docusate) prophylactically when initiating or continuing opioid therapy 2, 1
Monitoring Requirements
- Reassess pain control within 24-48 hours of conversion 1
- Monitor closely for respiratory depression, especially within the first 24-72 hours 3
- Adjust dosage to obtain appropriate balance between pain management and opioid-related adverse reactions 3
Important Caveats
- The oral-to-oral conversion from extended-release to immediate-release morphine is 1:1 for total daily dose 3
- Individual patient variability exists, and clinical judgment must be used to titrate to the desired response 2
- Dose titration can be accomplished with immediate-release morphine formulations 4
- Most patients achieve adequate analgesia with morphine, though approximately 6% may discontinue due to intolerable adverse effects 4