Need some clarification on these codes, any help would be greatly appreciated!

CPT 80154 - How many can I bill? Is it once per class? Per drug? Per procedure? - We perform about 8 benzo tests. MUE says 2.

CPT 82145 - We test for both Amphetamine and Methamphetamine, can I bill for each? MUE only says 1.

CPT 83925 - Per CPT ..each procedure, so is this only billed once? MUE says 4.

These tests are being done through an LC/MS.