Substances other than alcohol will not affect readings the device makes (because it only measures alcohol). So, antibiotics or throat lozenges won't affect a reading, unless they contain, alcohol. Some mouthwashes contain alcohol, and even though not swallowed, could result in higher intoxilyzer readings.

To really understand the law, the Arizona law concerning intoxication while driving has language which specifies that impairment to the slightest degree may be punishable. This means that being impaired, or less able to drive, may be a crime, from any source or cause of impairment.

Theoretically, if a person were to consume something which was not a common medication, such as kava kava or iced tea, and were to become impaired from it and then drive, they could be found to be impaired within the meanig of the law, and could be punished. While a cause of impairment may not be alcohol and would not show up on an intoxilyzer reading, field sobriety tests will usually indicate whether a person is impaired or not.

The broader meaning of the law is that if medicinal substances, whether alcohol based or otherwise, cause impairment to the slightest degree, an impaired driver may be punished under the law.