Codeine

While effective, codeine commonly causes several adverse reactions: Codeine - StatPearls - NCBI Bookshelf - NIH

: It is often paired with non-opioids like acetaminophen or ibuprofen to enhance pain relief through synergistic effects. Common Side Effects codeine

Codeine is a "prodrug," meaning it is relatively inactive until it is metabolized in the liver. An enzyme called converts codeine into morphine, which then acts on the brain's opioid receptors to block pain signals and produce feelings of relaxation or pleasure. codeine