Is there a maxiumum dosage for narcan (naloxone)?

Yes: The maximum dosage for any individual depends on many factors, however the manufacturer oftens states a maximum dosage for certain individuals. There is a maximum dosage for all medications.

Yes: Current practice is to give 2 mg intravenously, and then you can repeat that twice. With some narcotics, especially long-acting ones like darvon, Methadone and some others, it may require 5 mg to reverse overdose. Most authorities believe that if 10 mg doesn't reverse, it either isn't narcotics or its too late.

Yes: When narcan is administered intravenously or intramuscularly to an adult – repeated doses may be given to a total of 10 MG. REF: https://www.pdr.net/drug-summary/Narcan-naloxone-hydrochloride-3837