med 18

 

intoxication:

0.1 mg/kg/dose IV

Use preservative free formulations (PF).

Neonates are more susceptible to

respiratory depression (morphine-3-

glucuronide—predominant metabolite in neonates).

Adult clearance values by 6 mo of age.

Slower rates of dependence and withdrawal vs. fentanyl.

May delay attainment of full enteral feeding in the preterm neonate.

Long-term AE on neurologic system in

preterm infants remains unclear.

Analgesic effect on acute pain in preterm neonates remains controversial.

Morphine considered safer than midazolam for neonates requiring sedation.

May require exceeding maximum dose in

opioid tolerance with close monitoring.

Semisynthetic

opioid

Muopioid

receptor

agonists

Codeine Binds to Mu opiate

receptors in

CNS inhibiting

ascending pain

pathways; altering the perception of and

response to pain;

generalized CNS

depression; antitussive

Codeine has 1/10 of

receptor affinity

of morphine-

“prodrug.”

Hepatic:

Activation via CYP2D6

to morphine to morphine.

Glucuronide conjugation to morphine-6-

glucuronide (active)

and morphine-3-

glucuronide (inactive).

Ultra rapid metabolizers:

(≥2 copies CY2D6

alleles) risk opioid toxicity due to extensive

conversion of codeine

to morphine.

10% of dose eliminated

in urine as parent drug

Half-life: Neonates: 4.5 h

Infants: 2.6 h

Oral, tablets, liquid, IM, SC

injection

Available with

acetaminophen in elixir:

24 mg acetaminophen and

2.4 mg codeine

per mL (refer

to acetaminophen dosing

for max limit

for age)

0.5–1 mg/kg/dose

q4–6h

IM: Avoid—painful,

erratic absorption

Do not administer IV;

causes severe hypotension.

Naloxone:

Neonatal depression:

0.1 mg/kg/dose IV/

IM/SC.

May repeat q2–3

min as needed

Neonatal opiate

intoxication:

0.1 mg/kg/

dose IV

Analgesic effect dependent on conversion to morphine.

Codeine injection (not available in U.S.,

available in Canada): Codeine phosphate 15 mg;

30 mg/mL (may be given orally).

Contains sodium metabisulfite

preservative

Highly constipating vs. morphine

Consider possible impact of CYP2D6

polymorphisms.

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