Naltrexone used for Sexual Addiction?

My doctor just prescribed Naltrexone for me in attempt to treat my sexual addiction problem. Does anyone know about how successful this medication works for the treatment of sexual addictions? The drug is really used for Alcohol abuse treatment and people addicted to Heroion.
I checked the net but could not find anything that mentioned specifically of its use to treat sexual addictions.
I am a male, by the way. Also I am worried can it make a man have erectile dysfunction?

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