49 CFR § 392.4 - Drugs and other substances.
(a) No driver shall be on duty and possess, be under the influence of, or use, any of the following drugs or other substances:
(1) Any 21 CFR 1308.11 Schedule I substance;
(2) An amphetamine or any formulation thereof (including, but not limited, to “pep pills,” and “bennies”);
(3) A narcotic drug or any derivative thereof; or
(c) Paragraphs (a) (2), (3), and (4) do not apply to the possession or use of a substance administered to a driver by or under the instructions of a licensed medical practitioner, as defined in § 382.107 of this subchapter, who has advised the driver that the substance will not affect the driver's ability to safely operate a motor vehicle.
(d) As used in this section, “possession” does not include possession of a substance which is manifested and transported as part of a shipment.
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