A common defence by people caught drink driving is they are taking cold and flu medicine. I aimed to bring a bit more balance to this. I consumed the following mix;
Paracetamol - 975mg
Dextromethorphan - 45mg
Doxylamine succinate - 18.75mg
Alcohol - 4.5mL (~3.60g)
Keep in mind, this is an American product and is not available in Australia. The only ones similar to it are Schedule Four (S4) and can only be lawfully obtained by a doctors prescription.
Here is how the timeline went;
2230 - Took the mix orally
2234 - Undertook a breath alcohol test on a prescribed device, BrAC 0.043
2236 - BrAC 0.025
2237 - BrAC 0.017 2238 - BrAC 0.011
2239 - BrAC 0.013
2240 - BrAC 0.006
2241 - BrAC 0.000
2245 - BrAC 0.000
So within 11 minutes my BrAC was 0.000*, Additionally, as stated above, NyQuil is no longer available commercially in Australia and most mouthwashes and medicines are alcohol free now. But if, like me, you have an old bottle lying around, I doubt taking the prescribed amount will put you over the limit for a normal car driver.
Queensland Truck Drivers, Learners and Provisional drivers may want to be careful though as even blowing 0.006 will see your licence disqualified for drink driving.
Can I use the defence that it was a prescribed medicine?
No, just like you can't use that defence if you pass out due to Benzo's the doctor prescribed. If you consume alcohol whether from an alcoholic beverage, medical device or from a medicine - the fact still remains you drove with alcohol in your system.
Additionally, as Dextromethorphan has sedative properties - it is never a good idea to drive after taking a cold/flu medicine such as NyQuil.
*I am 6'8" and have a nice healthy liver, so my ability to filter alcohol would be better than a short person with a faulty liver.