Morphine

Introduction

Morphine is an opioid analgesic with agonist activity mainly at  opioid receptors. Morphine is used for the relief of moderate to severe pain, especially that associated with cancer, myocardial infarction and surgery.

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Morphine Syrup	MORP26	DD
Morphine SR Tab 10mg	MORP04	DD
Morphine SR Tab 30mg	MORP05	DD

Mechanism of Action

Pain relief Opioid analgesic

Equivalent doses of opioid analgesics

Analgesic/Route	Dose
Codeine: PO	100 mg
Diamorphine: IM, IV, SC	3 mg
Dihydrocodeine: PO	100 mg
Morphine: PO	10 mg
Morphine: IM, IV, SC	5 mg
Oxycodone: PO	6.6 mg
Tramadol: PO	100 mg

Dosage

Morphine is usually administered as the sulphate. Doses are expressed as the salts. Dosage routes include the oral, subcutaneous, intramuscular, intravenous, intraspinal, and rectal routes.

For pain:

• Oral doses are usually equivalent to 5 to 20mg every 4 hours as syrup, or as immediate-release tablet. With modified-release preparations the 24-hour dose is usually given as a single dose or in 2 divided doses. With all modified-release preparations, additional doses of immediate-release tablet may be needed if breakthrough pain occurs.
• Rectally as suppositories in doses of 10 to 30mg every 4 hours.
• Subcutaneous or intramuscular injection is 10mg every 4 hours but may range from 5 to 20 mg.

For myocardial infarction:

• Intravenous injection of 5 to 10 mg given at a rate of 1 to 2 mg/minute

Doses in children

The following initial doses are recommended by the BNFC according to age; doses should thereafter be adjusted according to response:

By subcutaneous injection:

• Neonates: 100 micrograms/kg every 6 hours
• 1 to 5 months: 100 to 200 micrograms/kg every 6 hours
• 6 months to 1 year: 100 to 200 micrograms/kg every 4 hours
• 2 to 11 years: 200 micrograms/kg every 4 hours
• 12 to 17 years: 2.5 to 10 mg every 4 hours

By intravenous injection over at least 5 minutes:

• Neonates: 50 micrograms/kg every 6 hours
• 1 to 5 months: 100 micrograms/kg every 6 hours
• 6 months to 11 years: 100 micrograms/kg every 4 hours
• 12 to 17 years: 5 mg every 4 hours

By mouth or rectum:

• 1 to 2 months: 50 to 100 micrograms/kg every 4 hours
• 3 to 5 months: 100 to 150 micrograms/kg every 4 hours
• 6 to 11 months: 200 micrograms/kg every 4 hours
• 1 to 11 years: 200 to 300 micrograms/kg every 4 hours
• 12 to 17 years: 5 to 10 mg every 4 hours

For severe chronic pain: 5-10 mg q4h, adjusted if needed.

IV Child dose based on body weight. adjusted if needed.

Palliative care pain management dose: 20-60 mg in divided dose depends on where the patients was on opioid before.