Combinations - Cocaine antagonist, to kill cocaine effects

[Fantasian]

Hey all SWIF is relatively unfamiliar with cocaine use however is asking the following question for a friend. Excuse any obvious lack of knowledge that he presents.

Here is my issue
SWIF has a good friend who once used cocaine pretty heavily she hasnt used in 3 years and wants to start using on a rare special occasion basis she is worried however that she'll go overboard on the night becuase once she starts on that night she cant stop she wondered whether if she took diazepam after she'd taken so much it would stop cocaines effects regardless of whether she took more. Similar to how a Heroin user might take Nalaxone to stop him using anymore.

If not what other drugs would force the cocaine experience to end?