Morphine hydrochloride - oral
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Dose and administration
Neonatal Abstinence Syndrome
- Start at 500 micrograms/kg/day orally1.
- This is usually prescribed 6-hourly. Dose may need to be increased with severe withdrawal before weaning can take place.
- Reduce dose by 10-15% of the original dose every 2-3 days as tolerated.
- Ventilated 100 - 200 micrograms/kg/dose.
- Non-ventilated 50 micrograms/kg/dose
- Neonatal Abstinence Syndrome
Contraindications and precautions
- Known hypersensitivity to opiates.
- Hypovolaemia, hypotension.
- Caution in preterm infants, especially very immature.
- Caution in neonates with hepatic and renal impairment.
- Caution in neonates with cardiac arrhythmias.
Morphine hydrochloride is a narcotic analgesic which stimulates opioid receptors in the central nervous system (mimics actions of encephalins and β endorphins). Produces respiratory depression by direct effect upon brain stem respiratory centres. No major effect upon cardiovascular system in analgesic doses. Resistance and capacitance vessels are dilated by the opioids. Gastrointestinal secretions and motility are decreased while tone is increased. Stimulates smooth muscle of biliary and urinary tracts.
Well absorbed from gastrointestinal tract but high first pass hepatic metabolism. Low binding (20%) to human plasma protein. Hepatic metabolism to glucuronide and other metabolites. Excretion via the kidney - significant amounts of unchanged drug in the neonate. The pharmacokinetics of morphine in the neonate are very variable.
Variable onset of action after oral administration. Analgesic effects occur with plasma concentrations around 120ng/ml. Respiratory depression occurs with plasma concentrations >300ng/ml. In the non-withdrawing baby respiratory depression is more likely.
Possible adverse effects
- Respiratory depression.
- Gastrointestinal disturbances (vomiting and spilling, ileus, delayed gastric emptying, cramps, and constipation.
- Physical dependence
- Urinary retention.
- Morphine is the drug of choice for most situations requiring pain relief
- Wean slowly after prolonged use of morphine.
- Management of morphine toxicity: stop morphine, support infant (ventilation, external cardiac massage, volume expansion etc.), Naloxone (0.1 - 0.2 mg/kg/dose IM). Naloxone is never used for babies with Neonatal Abstinence Syndrome.
- For further information about its use in narcotic withdrawal see Neonatal Abstinence Guideline.
Management of oral Morphine Hydrochloride administration
The mixture (Delta West brand) contains morphine 1 mg/ml (=1000 micrograms/ml), glycerol (less than 10%), methylhydroxybenzoate (preservative) in a citrate-buffered clear aqueous vehicle.
Charted on prescription chart as morphine mixture in mcg/dose.
- Administer with a small volume of milk.
- When dose is <50 micrograms, dilution to 500 micrograms/ml is necessary.
- Using a 1 ml syringe, draw up 0.5 ml water ensuring the hub of the syringe does not contain water.
- Using a 2nd 1 ml syringe and needle, draw up 0.5 ml morphine hydrochloride 1 mg/ml priming hub of syringe and needle.
- Dispense morphine into the water and mix well.
- Prime to ordered dose.
Observation and documentation
- Evaluate the baby's need for medication.
- Evaluate baby's response to medication.
- Assess for signs of adverse effects.
- Monitor respiratory status carefully.
- Assess oxygenation and document.
- Observe stools for volume and character.
- Record baby's dose out of the narcotic register.
- When diluting morphine to 500 micrograms/ml, record balance discarded out in the narcotic register.
- Two nurses must witness the discarding of the unused diluted drug down the sink and syringes into the sharps container.
- Store in the controlled drug safe.
- Expiry date is six months from date of opening bottle, or manufacturers expiry date - whichever is shorter.
- Osborn D. Neonatal Abstinence Syndrome. Protocol from the Department of Neonatal Medicine, RPA Hospital, Camperdown, Sydney, Australia. June 1998
- Wijburg FA, de Kleine MJK, Fleury P, Soepatmi S. Morphine as an anti-epileptic drug in neonatal abstinence syndrome. Acta Paediatr Scand 1991; 80 : 875-877.
- Thomas D. Infants of drug-addicted mothers. Aust Paediatr J. 1988; 24:167-168.
- Bhat R, Gopa C, Gulati A, Mdana 0, Velamati R, Bhargava H. Pharmacokinetics of a single dose of morphine in preterm infants during the first week of life. J Pediatr 1990; 117 : 477-81.
- Bhat R, Abu-Harb M, Gopal C, Gulati A. Morphine metabolism in acutely ill preterm infants. J Pediatr 1992; 120: 795-9.
- Lynn AM, Slattery JT. Morphine pharmacokinetics in early infancy. Anesthesiology 1987; 66:136-9.
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- Date last published: 28 February 2001
- Document type: Drug Dosage Guideline
- Services responsible: ADHB Pharmacy, Neonatology
- Editor: Sarah Bellhouse
- Review frequency: 2 years