Naloxone: underdosage after narcotic poisoning
R. A. Moore, B. H. Rumack, C. S. Conner and R. G. Peterson
A case of propoxyphene hydrochloride (Darvon) poisoning was unresponsive to
therapeutic doses of naloxone hydrochloride in a 2 1/2-year-old girl.
Following prolonged coma and artificial ventilation for three hours, the
patient responded immediately to the intravenous administration of 2 mg of
naloxone hydrochloride, which is 20 times the manufacturer's recommended
dosage. Naloxone is the agent of choice in reversing the effects of
narcotics and synthetic opiate derivatives, such as propoxyphene and
pentazocine. The manufacturer's present recommended dosage may not be
sufficient to reverse the effects of large narcotic ingestions. We
therefore recommend that if there is no response within two minutes of the
initial 0.01 mg/kg dosage of naloxone hydrochloride, a second dose 0.1
mg/kg (ten times the manufacturer's suggested dose) be given.
