JK is a 41yof who is currently treated with Methadone 120mg PO daily for heroin dependence. She was just diagnosed with HIV & her physician has prescribed her combination therapy with Efavirenz + Tenofovir/Emtricitabine. She is picking these meds up today at your pharmacy. Which of the following is the best reason to contact the prescriber?

a. The methadone should be switched to buprenorphine/naloxone due to methadones higher abuse potential
b. The dose of methadone will need to be decrease due to drug interaction
c. The methadone dose is too high for heroin dependence & should be reduced
d. These meds should not be taken together due to potential to cause methadone withdrawal