Talking about his youth, the Buddha said that when as the bodhisatta he
saw an old man, all intoxication of youth vanished from his mind; when he
saw a sick man, all intoxication of health vanished; and when he saw a
dead man, all intoxication with life vanished from his mind.

Intoxication (pamada) is everywhere blamed, and rightly so. Any Buddhist
who is so intoxicated with life or youth or health that they can indulge
in drink or drugs, thinking that they will not become intoxicated by a
small amount, is surely being heedless already.

It take the precept to mean, "I undertake the precept to abstain from
intoxicants that causes heedlessness." Whether one becomes intoxicated or
not, one should abstain from them if one has undertaken to do so.

The Paacittiya rule for monks doesn't say that one falls into an offence
only if one becomes intoxicated.

From Buddhist Monastic Discipline Volume I

"Effort. The Vibhanga defines drinking as ***taking even as little as the
tip of a blade of grass.*** Thus taking a small glass of wine, even though
it might not be enough to make one drunk, would be more than enough to
fulfill this factor.

According to the Commentary, the number of offenses involved in taking an
alcoholic drink is determined by the number of separate sips. As for
intoxicants taken by means other than sipping, each separate effort would
count as an offense.

Non-offenses. The Vibhanga states that there is no offense in taking
alcohol "mixed in broth, meat, or oil." The Commentary interprets the
first two items as referring to sauces, stews, and meat dishes to which
alcoholic beverages, such as wine, are added for flavoring before they are
cooked. Since the alcohol would evaporate during the cooking, it would
have no intoxicating effect. Foods containing unevaporated alcohol -- such
as rum babas -- would not be included under this allowance.

As for alcohol mixed in oil, this refers to a medicine used in the
Buddha's time for afflictions of the "wind element." The Mahavagga (VI.14.
1) allows this medicine for use only as long as the taste, color, and
smell of the alcohol are not perceptible. From this point, the Vinaya
Mukha argues that morphine and other narcotics used as pain killers are
allowable as well."