Elimination half life is prolonged in neonates due to reduced hepatic activity and
blood flow [2,13,14](Table 1)
- Morphine [5,13,14]
Clinical characteristics: most commonly used opioid for
management of pain
Dosing: IV 0.1mg/kg; Oral route: 1:3 conversion IV to oral
(due to high first pass effect)
Onset and elimination: peak effect 20 minutes; duration of
action 2-7 hours; Half life 2-3 hours in infants, 9 hours in
preterm neonates, 6.5 hours in term neonates
Precautions:
o renal failure patients or neonates with decreased GFR
can have accumulation of morphine 6-glucuronide
(active metabolite), which can cause respiratory
depression.
o Cirrhosis, septic shock, and renal failure decrease the
clearance of morphine and metabolites.
o Can produce venodilation, histamine release,
hypotension - Fentanyl [13]