What Is the Antidote for Morphine?

The most well-known and most often administered antidote for morphine is the opioid antagonist naloxone, which has significant beneficial action on all three types of opioid receptors to which morphine binds. Its prolific binding to all the subsets of the targeted opiate receptors lends to its classification as the first line defense in patients who have overdosed and are suffering from the life-threatening symptoms of morphine poisoning. Naloxone takes effect in as little as 30 seconds after intravenous administration, an attribute that provides significant benefit in dire situations where patient respiration has stopped or is on the verge of stopping. Nalorphine and naltrexone are alternative opioid antagonists; each may be used as an antidote for morphine if there is a hypersensitivity to naloxone, if there are other health considerations that precipitate their use, or when naloxone is not readily available. All three antidotes work by “pushing” the morphine out of the opioid receptors in the patient’s brain, reversing the symptoms of overdose.

If an overdose is suspected, rapid transport to the emergency room for the administration of an antidote for morphine greatly increases the patient’s chance of survival and complete recovery from the poisoning. Typical symptoms that indicate a serious overdose and the need for an antidote include vomiting, drowsiness, and pupils that are significantly pinpointed. Seizures, difficulty breathing, and bluish-colored lips and fingernails are even more serious symptoms that require transport to a facility within a few minutes, preferably in an ambulance to ensure that there is supportive breathing technology available if cessation of respiration occurs. Many first responders carry an antidote for the medication, most often naloxone, with them to the scene. For this reason, supporting family or friends should be ready to relay the patient’s weight, age, and approximate amount of morphine that is suspected to have been ingested to the emergency personnel when they arrive, or if the patient is taken by car, upon arrival in the emergency room.

After an initial dose of the prescribed antidote for morphine has been administered on the scene, in the ambulance, or in the emergency room, close observation for a few hours in an inpatient setting is standard medical protocol. Close observation is vital because, with the exception of naltrexone, the half-life of many opiate medications outlasts that of the antidote for morphine and subsequent doses may be needed to keep the patient from overdosing for a second time. Naltrexone is primarily given to addicted-type patients as a long-acting opiate antagonist to reduce cravings and greatly reduce the likelihood of recreational morphine use. The other opioid antagonist referred to, nalorphine, is an older drug from the 1950s and is not as effective in acute overdose situations because of its limited binding affinity to the targeted opioid receptors.