can people who are known cigarette-addicts be trusted around pharmasuticals?

Assuming you're not trolling, there's no reason to believe this person would become addicted to pills (or even start taking them recreationally) simply because he smokes cigarettes. His habit of 4 cigarettes a day certainly isn't as significant as others who smoke half a pack or a full pack a day. If they make the assumption that he will become a pill popper simply because he smokes cigarettes, I'd question what kind of place it is he wants to work.

As a side note, how is it that you have a "friend" who you "don't like all that much"?

And if you really cared about him quitting smoking, you wouldn't hound him - that usually isn't effective (as it sounds like you have learned). People are more likely to seek change if they are supported instead of shamed.

Four cigarettes a day is hardly an addiction. Some people like to drink soft drinks or eat burgers or chocolate bars. We each have our chosen weakness.

I see no reason this would affect a person's suitability for working for working around pharmaceuticals.

When giving a reference, we have to be very careful what we say and the way we say it. Not only do we have to be fair towards the person in question but we can be held legally responsible for what we say.

OMG!! The fact that you just compared a cigarette smoker to being a pill addict is unbelievable!! Cigarettes do not give you a "high". That has absolutely nothing to do with a drug addiction!!! I bet money that they will not even ask you about his smoking habit. That also doesn't have anything to do with his ability to perform well on a job. Don't be ridiculous!

I don't think it would be an issue at all. Lots of people smoke cigarettes. I know doctors who smoke and they are not pill poppers. Huge difference. Nicotine is a psychological addiction, but also a physical one.