A patient takes a drug that is metabolized by CYP3A4 isoenzymes. If a CYP3A4 inducing drug is prescribed, what drug adjustment may be necessary to maintain a therapeutic level of CYP3A4 substrate?
a) Increase dosage of the CYP3A4 inducer.
b) Decrease dosage of the CYP3A4 inducer.
c) Increase dosage of the CYP3A4 substrate.
d) Decrease dosage of the CYP3A4 substrate.