According to VIC Law for the charge of Exceed prescribed concentration of drugs (drug driving),

Road Safety Act 1986 - SECT 49

Offences involving alcohol or other drugs

49. Offences involving alcohol or other drugs

(1) A person is guilty of an offence if he or she-
(i) has had a sample of blood taken from him or her in accordancewith section 55, 55B, 55E or 56 within 3 hours after driving or being in charge of a motor vehicle and-

(i) the sample has been analysed by a properly qualified analyst within the meaning of section 57 and the analyst has found that at the time of analysis a prescribed illicit drug was present in that sample in any concentration; and

(ii) the presence of the drug in that sample was not due solely to the consumption or use of that drug after driving or being in charge of the motor vehicle.

According to VIC Law for the charge of Exceed prescribed concentration of drugs (drug driving),

First offence: 12 penalty units

Second offence: 120 penalty units or a 12 months imprisonment (dependent on the concentration)

Subsequent offence: 180 penalty units or 18 months imprisonment.

Note: A person who is guilty of an accompanying driver offence is liable to a fine of not more than 5 penalty units.

(a) The accused had a sample of blood taken within 3 hours after driving or being in charge of a motor vehicle.

(b) The sample showed that a prescribed illicit drug was present in any concentration, or the presence of alcohol above a prescribed concentration.

(c) The result was not due solely to the consumption or use of that drug after the driving or being in charge of that motor vehicle.

(a) Factual dispute.

(b) The result of the anlaysis was not a correct result.

(c) The accused did not know and could not reasonably have known that the permissible non-prescription drug or the prescription drug, or the combination of those drugs, would impair driving if consumed as advised by an authorised medical practitioner.

Magistrates' Court.