It is arguably a bit of a misnomer to cast Epicurus (as history often has) as a person purely interested in mere pleasure. A better term that has been used is 'untroubledness'. As you note, he found some kinds of pleasure markedly superior to others. Perhaps it would help if we cite an example:
If a hungry man were guided to a feasting table groaning with the weight of all manner of fine foods and wine, we can probably anticipate that he will soon be quite happy. But Epicurus would point out many ways this man might immediately go wrong in his pursuit of that pleasure. If he eats too much too fast, he is very likely to make himself sick, likewise if he focuses entirely on rich foods. He could drink too much and then do something he'd regret later, or have to deal with a hangover. Even if everything goes well, tomorrow he might be sad that there is no similarly laden table to sate his desires.
This is why Epicurus focuses most on a kind of abstemious modesty in how he advocates pleasure. One of the most persistent and unnecessary barbs, he thought, was desire (followed by fear). So many people seem to want so much more than they have or can get. Better by far, he thought, to set one's desires to the absolute minimum ("Do not spoil what you have by desiring what you have not"). And I mean minimum... I seem to recall (but can't find) a quote from him saying he'd prefer a crust of bread and the company of a friend to that aforementioned table. Or even just a quiet place to think.
As such, perhaps you can see why he would turn down the most consequence-free drugs, or why even a sunset might be overlooked. You don't NEED those things and enjoying them too much can lead to a want from their absence. Epicurus thought pleasure was a thing that could always be right at hand, if you only set your mind right about it ("Being happy is knowing how to be content with little").
