The autonomic nervous system is the part of the nervous system that controls muscles of internal organs (such as the heart, blood vessels, lungs, stomach, and intestines) and glands (such as salivary glands and sweat glands).
Naltrexone is also used to reduce cravings for alcohol. Scientists are unsure how it works in relation to alcohol but it has been shown to reduce desire and cravings by blocking the same receptors that create feelings of pleasure when opioids are taken.
Naltrexone will cause withdrawal symptoms in people who are physically dependent on narcotics. Naltrexone treatment is started after you are no longer dependent on narcotics. The length of time this takes may depend on which narcotic you took, the amount you took, and how long you took it. Before you start taking this medicine, be sure to tell your doctor if you think you are still having withdrawal symptoms.