Naloxone hydrochloride

Source: Naloxone Hydrochloride 1 mg/ml Solution for Injection in a pre-filled syringe (UK SPC). Opioid overdosage (known or suspected): an initial dose of 400 to 2000 micrograms may be administered intravenously; if the desired degree of counteraction and improvement in respiratory function is not obtained it may be repeated at 2 to 3 minute intervals. Intramuscular or subcutaneous administration may be necessary if dosing by the intravenous route is not feasible. The duration of action of certain opioids can outlast that of an IV bolus of naloxone, e.g. dextropropoxyphene, dihydrocodeine and methadone; where one of these opioids is known or suspected it is recommended that an infusion of naloxone be used to produce sustained antagonism without repeated injection. Post-operative use: the dose should be titrated for each patient to obtain optimum respiratory response while maintaining adequate analgesia; intravenous doses of 100-200 micrograms (approximately 1.5-3 micrograms/kg body weight) are usually sufficient, but a full two minutes should be allowed between each 100 micrograms increment administered. Further intramuscular doses may be needed within one to two hours, depending on the interval since the last opioid administration and the amount and type (long- or short-acting) of drug used. Intravenous infusion: naloxone may be diluted in normal saline (0.9%) or 5% dextrose in water or saline; the addition of 2 mg (2 ml of 1 mg/1 ml concentration) in 500 ml of either solution provides a concentration of 4 micrograms/ml. Mixtures should be used within 12 hours; after 12 hours the remaining unused solution must be discarded. The rate of administration should be titrated in accordance with the patient's response to both the infusion and any previous bolus doses. Parenteral drug products should be inspected visually for particulate matter and discolouration prior to administration. Elderly: there have been no specific studies for use in the elderly. Neonatal use: an adequate airway should be established in the apnoeic infant before naloxone is administered; the usual dose for opioid-induced depression is 10 micrograms/kg body weight IV, IM or SC, repeated at 2-3 minute intervals if the desired degree of counteraction and improvement in respiratory function is not obtained; alternatively a single dose of 200 micrograms (approximately 60 micrograms/kg body weight) may be given intramuscularly at birth, noting that onset of action is slower following IM injection. In neonates needing infusion of naloxone in saline, care should be taken to avoid excessive sodium intake.

Paediatric population: the usual initial dose in children is 10 micrograms/kg body weight given IV. If this dose does not result in the desired degree of clinical improvement, a subsequent dose of 100 micrograms/kg of bodyweight may be administered. Naloxone may be required by infusion (2 mg in 500 ml giving 4 micrograms/ml, titrated to response). If an IV route of administration is not feasible, naloxone may be administered IM or SC in divided doses. Neonatal use: establish an adequate airway in the apnoeic infant before administration; usual dose for opioid-induced depression is 10 micrograms/kg IV, IM or SC, repeated at 2-3 minute intervals if response is inadequate; alternatively a single dose of 200 micrograms (approximately 60 micrograms/kg) IM at birth, with slower onset of action. Verify against a children's formulary.