79. Defence of drug or psychoactive substance taken for medical purposes

In any proceedings for an offence under section 76, it is a defence to prove that at the time of the act or omission alleged against the defendant, the defendant was under the influence of a drug or psychoactive substance taken by him or her for medical purposes and either that he or she took it on medical advice and complied with any directions given as part of that advice or that he or she had reason to believe that the drug or psychoactive substance might not have the influence it had.