When enzymes change: induction, inhibition and genetics
Explains most drug interactions and why the same dose affects people differently.
Where this fitsConnects to 1 · Unlocks 2
- Connects to
- Metabolism and excretion: the liver and kidneys — The CYP enzymes from the previous chunk.
- Unlocks
- First-pass metabolism and prodrugs — Inhibiting first-pass enzymes can make an oral drug active (ayahuasca).
- Half-life and redistribution — Faster or slower metabolism changes half-life.
Orient
Enzyme induction – levels of enzymes can be increased by previous exposure to a specific drug. Enzyme inhibition – some drugs inhibit CYP enzymes, which can increase their own levels as well as levels of any other drug metabolized by that enzyme. Genetic differences make people slow, normal, or fast metabolizers.
Course terms
Your professor's wording, word for word from the slides. Learn the term and this definition — the explanation underneath is only there to help it make sense.
- Enzyme induction
“Levels of enzymes can be increased by previous exposure to a specific drug - enzyme induction”Slides 04, p. 37
e.g., heavy drinking increases alcohol dehydrogenase.
- Enzyme inhibition
“Some drugs inhibit CYP enzymes”Slides 04, p. 37
Raises levels of every drug that enzyme metabolizes — toxic or useful (carbidopa + levodopa).
- CYP-3A4 and grapefruit
“Inhibited by furanocoumarin in grapefruit juice”Slides 04, p. 38
Sometimes useful, sometimes dangerous.
- Slow / normal / fast metabolizer
“DNA testing can detect slow, normal, or fast metabolizer for specific drug”Slides 04, p. 40
Genetic differences in CYP enzymes change efficacy and side effects.
From your course: Course slides 04, pp. 37–40
Tip: the ← and → keys move through the lesson.
Full lesson: Enzyme induction, inhibition and variation