DOT Rule 49 CFR Part 40 Section 40.141
Subpart G - Medical Review Officers and the Verification Process
§ 40.141 How does the MRO obtain information for the verification decision?
(1) You may contact the employee's physician or other relevant medical personnel for further information.
(i) If you decide to contact the employee's pharmacy to authenticate whether the prescription offered by the employee was filled by the pharmacy, you or staff under your operational control can contact the pharmacy.
(ii) If you utilize staff to perform the inquiry in paragraph (b)(1)(i) of this section, you must ensure operational control over the hiring, firing, evaluation of the staff and you must oversee the performance of the function of contacting a pharmacy to authenticate specific prescription(s) (e.g., outline or script what the staff will ask the pharmacy; occasionally monitor calls to assure quality control; or other methods to ensure the staff are properly conducting the calls with the pharmacies).
(2) You may request an HHS-certified laboratory with validated protocols (see § 40.81(c)) to conduct testing for D,L stereoisomers of amphetamine and methamphetamine or testing for tetrahydrocannabivarin (THC–V) when verifying lab results, as you determine necessary.