The problem with most answers to this question is that they render Buddhism worthless to many people.
None of us here know exactly what the Fifth Precept means. It is quite possible that what it means is to abstain completely from drug and alcohol usage; but it is equally possible that there is something else behind it. In Christianity, literal interpretations of the Bible have lead to hatred, violence, and stupidity. The examples abound.
Imagine someone who is suffering from some sort of chemical dependency - call it psychological. Hypothetically; this person only knows how to feel confident meeting new people when they are drinking. For this person, believing that they can only practice Buddhism by abstaining completely from intoxicants, will be completely dis-empowering.
Using the 'realms of existence' metaphor - we could say that this person is in a certain level of 'Hell'. Since one can't attain liberation while in 'Hell', they should do nothing, right?
But of course this is not the case. Inaction is mostly less useful than incomplete action.
Wittgenstein, a German philosopher once famously said,
My propositions serve as elucidations in the following sense: anyone who understands me eventually recognizes them as nonsensical, when he has used them - as steps - to climb up beyond them.
(He must, so to speak, throw away the ladder after he has climbed up it.)
When one is undertaking Buddhist practices, one is already doing something that will further their growth. If one reaches the point where what is between him and the next level of awakening is to discontinue intoxicants, he will know that before he could learn it from a precept.
But if one must first eradicate all desires and sensory pleasures before undertaking the journey, the journey will be a short one indeed - the journey before the journey will be the journey.
Buddhism is both dogmatic and non-dogmatic. It's dogmatic nature can give rise to deep spiritual discipline when practiced with rigor at a very high level - but as with any dogma - it can strangle practitioners - confuse them into clinging to their own understanding of an interpretation rather than opening themselves to a larger context.
It is easy to see the non-dogmatic aspects in Buddhism - as stated here by Venerable Sumedho:
Suttas are not meant to be 'sacred scriptures' that tell us what to believe. One should read them, listen to them, think about them, contemplate them, and investigate the present reality, the present experience with them. Then, and only then, can one insightfully know the truth beyond words.
And two other quotes that seem to fit the context that I am creating:
When I do not know who I am, I serve you.
When I know who I am, I am you
... and perhaps my all time favorite
The genuine path of unminding is not a religion for the immature.
Note: I am aware that this response jumps around. I was looking to capture the space of several points rather than promoting a well-founded point of view.
Interestingly when looking up another quote for my response, I found the following quote:
The true meaning of the precepts is not just that one should refrain from drinking alcohol, but also from getting drunk on nirvana.
attributed to Bassui
And another cool one from The Alchemist by Paulo Coehlo. ( quoting Jesus I've learned)
It's not what enters men's mouth that is evil," said the alchemist. "It's what comes out of their mouths that is".