Description and indication for use

Morphine Sulphate is the principal alkaloid of opium and is a phenanthrene derivative. Morphine, as other opioids, acts as an agonist at stereospecific and saturable binding sites/receptors in the brain, spinal cord and other tissues.  Morphine is used to cause respiratory depression to enhance assisted ventilation, as a sedative and analgesic, and orally in the treatment of Neonatal Abstinence Syndrome.

Dose

IV STAT:

0.05 – 0.1 mg/kg (use higher dose as a premed for intubation).

IV Infusion:

10 – 20 micrograms/kg/hour.

Larger doses of up to 40 micrograms/kg/hr may be used (usually only if neonate/infant is ventilated).

Reconstitution/Dilution

Ampoule = 10 mg in 1 mL.        (Schedule 8 drug – Drug of Addiction safe).

IV 1:

For Intubation pre-med dose please see neat dosing guidelines in Medicines for Intubation and Resuscitation Quick Reference Guide page 121 [Appendix C].

IV 2 STAT:

Withdraw 0.1 mL of 10 mg/mL solution and add to 0.9 mL of water for injection in a second 1 mL syringe = 1 mg/mL.

Discard excess volume to obtain required dose or withdraw ordered dose using another syringe.

IV Infusion:

Dilution if required as above. 

Ordered dose should be made up to ordered volume of IV fluid in a 50 mL syringe.

(Refer to IV Infusion Chart).

Usual order for infusion will be as follows:

(Do not use infusion solution to give a stat dose of morphine - make up dose of morphine as described above under IV stat dose.)

Route and method of administration

IV STAT:

Give over 3 to 5 minutes.  Flush line.

IV Infusion:

Given as a continuous infusion via a syringe pump at the prescribed rate.

IM:

Not recommended in neonates.

Side effects

Respiratory depression.

Hypotension, flushing, sweating, tachycardia.  (Due to histamine release and peripheral vasodilation).

Respiratory arrest.

Bradycardia.

Urinary retention.

Muscle rigidity.

Diarrhoea, abdominal cramps, constipation, vomiting.

Miosis (contraction of the pupils).

Increased intracranial pressure.

Physiologic dependence/tolerance with prolonged use - therefore, wean slowly.

Hypotension and chest wall rigidity may occur with rapid administration.

Antagonist for respiratory depression

Naloxone 0.01-0.10 mg/kg/dose IV should be available for reversal. (Note: the half-life of Naloxone is very short, therefore Naloxone may need to be repeated).

Special precautions

CAUTION in patients with cardiac arrhythmias.

CAUTION in patients with hepatic or renal impairment.

CAUTION in patients with urinary retention.        

Contraindications:

Shock, hypotension.

Increased intracranial pressure, convulsions.

Compatible Solutions

Glucose 5%, Glucose 10%.

Terminal injection site compatibility (if administering Morphine as a continuous infusion):

Dobutamine, Dopamine, Adrenaline, Frusemide, Insulin, Midazolam, Potassium Chloride.

Incompatibilities

Morphine Sulphate must not be mixed together with the following drugs:

Minophylline, Fluconazole, Heparin Sodium (high concentration), Phenobarbitone Sodium, Thiopentone Sodium, Frusemide, Phenytoin.

Contact Pharmacy for further information if required.

Drug interactions

Some case reports of Morphine toxicity when given together with Cimetidine and Ranitidine.

Nursing responsibilities

Cardiorespiratory monitor.

Monitor blood pressure.

Ventilation equipment available. 

Bag and mask (connected to oxygen) and suction equipment present at bedside.

MEDICAL STAFF should be on hand when giving STAT dose as ventilation may need to be initiated/increased.

Check DRUG INCOMPATIBILITIES when giving medications into IV infusion that is being co-infused with Morphine.

Note: if Morphine is infusing in the same line as inotropes - no bolus medications should be given in that line.

Syringe changed every 24 hours and line changed every 72 hours (as per RCH central line protocol).             

Naloxone should be available for reversal, if necessary.

Check that rate ordered corresponds with dose required (micrograms/kg/hr).

Consider IDC for urinary retention.