|Reviewed by Dr Simon
Rowley and Dorothy Cooper
Dose and Administration
- 0.1-0.2 mg/kg/dose IM (0.25-0.5ml/kg of 0.4 mg/ml concentration)
May also be given IV, intratracheally or subcutaneously.
May repeat in 3-5 minutes if no response during resuscitation.
- Narcotic induced respiratory and
- Narcotic overdose.
Contraindications and Precautions
- Known or suspected naloxone hypersensitivity.
- Newborns of mothers who are known
or suspected to be physically dependent on opioids. In such cases an abrupt and
complete reversal of narcotic effects may precipitate an acute abstinence
- Not indicated if infant shows no sign of respiratory depression.
- Has no effect on non-narcotic induced respiratory and CNS depression.
- Naloxone is an adjuvant therapy to customary resuscitation efforts for narcotic induced respiratory depression.
Other resuscitative measures such as maintenance of a free airway, artificial
ventilation, cardiac massage and vasopressor agents should be employed as
- Caution in infants with tachycardia, congenital heart defects.
Naloxone is a pure narcotic
antagonist. It prevents or reverses the effects of opioids, including
respiratory depression, sedation and hypotension. Naloxone does not possess
agonist properties and therefore does not produce respiratory depression,
psychotomimetic affects or pupillary constriction. In the absence of opioids it
exhibits essentially no pharmacological activity. Naloxone antagonises the
opioid effects by competitive inhibition at the opioid receptor sites.
Following parenteral administration
naloxone is rapidly distributed in the body. It is metabolised in the liver,
primarily by glucuronide conjugation and excreted in the urine. When
administered intravenously its onset of action is rapid (within 2 minutes); the
onset of action is only slightly less rapid when it is administered
subcutaneously or intramuscularly. The duration of action is dependent upon the
dose and route of administration. Intramuscular administration produces a more
prolonged effect than intravenous administration.
Naloxone has not been shown to
produce tolerance nor to cause physical or psychological dependence. No
short-term toxicity has been observed but long-term safety has not been
investigated. There is no clinical experience with naloxone overdosage in
Possible Adverse Effects
- Abrupt reversal of narcotic depression may result in nausea, vomiting, sweating, tachycardia, increased
blood pressure and tremulousness.
- Tachycardia, hypertension.
- Gastrointestinal disturbances (nausea, vomiting).
- Lethargy, tremors.
- Elevated PTT.
- Infants receiving naloxone in the
delivery room because of narcotic induced respiratory depression require
observation afterwards. This observation need not necessarily be on the neonatal
- The duration of naloxone
antagonism may be less than the clearance of the opiate being antagonised. This
should not be a problem with the intramuscular administration of naloxone.
However, some babies may require a second dose of naloxone.