NaloxoneDose, contraindications and adverse effects for Cats, Dogs and Horses.

Pure opioid receptor antagonist; used to reverse opioid sedation, respiratory depression or overdose. Naloxone is used almost exclusively for its opioid reversal effects, but the drug has been investigated for treating other conditions (eg, septic, hypovolemic, or cardiogenic shock). Frequent administration of low-dose naloxone is advocated by some to reverse opioid effects while minimizing consequences of opioid withdrawal. Some have found low-dose naloxone useful in treating postanesthetic dysph

Naloxone is considered a pure opioid antagonist and has no analgesic activity at usual dosages. The drug acts as a competitive antagonist by binding to the mu, kappa, and delta opioid receptor sites, and has its highest affinity for the mu receptor. It also has some GABA antagonistic effects, which can elicit convulsions, although this is usually not clinically relevant.

Naloxone is contraindicated in patients hypersensitive to it. It should be used cautiously in animals that have preexisting cardiac abnormalities or that may be opioid dependent. Excessive naloxone doses or abrupt reversal following surgery may result in vomiting, tachycardia, blood pressure changes, ventricular arrhythmias, pulmonary edema, and seizures.

At recommended dosages, naloxone is relatively free of adverse effects in non-opioid dependent patients; however, when used to reverse opioid effects, it can also reverse any analgesic effects of the opioid (see Contraindications/Precautions/Warnings).

■ Because the duration of action of naloxone may be shorter than that of the narcotic being reversed, animals that are being treated for opioid intoxication or that have clinical signs of respiratory depression should be closely monitored for re-narcotization, as additional doses of naloxone and/or…