What is a fix in drugs?

Excuse me, could you please clarify what you mean by "a fix in drugs"? Are you referring to the term used in the context of illegal drug use, where "a fix" might signify a dose or hit of a drug that temporarily satisfies a user's addiction? Or is there a specific pharmaceutical or medical context you're alluding to? Understanding the precise meaning you intend would help me provide a more accurate and relevant response.