Answer 1) Off label
Example of common off label drugs
Prazosin (Minipress) for Nightmares.
Clomiphene (Clomid) for Male Infertility and multiple pregnancy
Memantine (Namenda) for OCD. ...
Clonidine (Catapres) for ADHD. ...
Quetiapine (Seroquel) for Insomnia.
Naltrexone (Revia) for Behavioral Addiction