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:
Drug
|
How to make up
|
Dose equivalent
|
Dose range
|
Morphine
|
1 mg/kg in 50 mL
glucose 10%
|
1 mL/hr = 20
micrograms/kg/hr
|
10-40 micrograms/kg/hr
|
(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.