A charge of driving under the influence of drugs (DUID) is different than a DUI offense. The criminal penalties are similar, but many states do not allow the DMV to suspend your driving privileges. The jurisdiction of the DMV arises out of violating the “per se” laws. The per se laws in each state make it a crime to operate a motor vehicle with a BAC over the legal limit. Since there are no per se levels established for DUID, the DMV does not have jurisdiction.
In most DUID cases, being under the influence is defined as being unable to operate a motor vehicle in the same manner as a sober person would. The primary question is whether the driver is too impaired to drive safely. The law does not care if the drug is legal, illegal, a prescription medication or an over the counter medication. The only question is whether the legal definition of DUID has been met.
If you have been detained on suspicion of DUI and you passed the preliminary breath test, the officer will suspect you of DUID. Once you have been arrested, most jurisdictions will require you to take a blood or urine test.