(1) Schedule VI shall consist of the drugs and other substances, by whatever official name, common or usual name, chemical name or brand name designated, listed in this section.
(2) Volatile nitrites. Unless specifically excepted or unless listed in another schedule, any material, compound, mixture or preparation containing any of the following drugs or their related compounds, congeners or isomers as follows: Amyl nitrite;
(3) Butyl nitrite;
(4) Isobutyl nitrite;
(5) Isoamyl nitrite;
(6) Isopentyl nitrite.
Except that any combination or compound containing amyl nitrite which is prepared pursuant to a prescription issued by a licensed practitioner is not a controlled substance for the purpose of this section.