Substrates
are drugs or other substances (xenobiotics) which are metabolized by cytochrome enzymes including1
pharmacologically active drugs which require metabolism to inactive form for clearance from the body metabolically activated drugs (prodrugs) which require conversion to active drug
Inhibitors
are substances which compete with other drugs for ≥ 1 CYP enzyme, affecting therapeutic response to that medication
Inhibitors will decrease clearance of substrates requiring biotransformation for excretion, and may lead to enhanced effect or toxic levels of the substrate
Inhibitors may reduce effect of substrates (produgs) which require conversion to active drug in the body
Inducers
are substances which increase CYP enzyme activity by increasing enzyme synthesis4
due to length of time to synthesize enzymes, full development of enzyme induction interaction may take days or weeks
interactions may be slow to resolve dependent on duration of enzyme in body (half-life)