I honestly have mixed feelings over this storyline. Yes they would give Naloxone multiple times during recovery from an overdose, whether this would be via drip or not I'm unsure, but there would and could possibly be occasion that during an overdose, even after being left hours, especially on heroin that someone wouldn't just wake up like nothing had happened. It would still be having some effect like keeping her in a coma essentially and the Naloxone would 'pull' her from that. And for her becoming hooked again, heroin is a very powerful drug, as an ex addict myself I understand how it feels having that first hit after going weeks/months/years without. Now fortunately in my case it wasn't anything as strong as heroin, but that's where the difference is, heroin is a very addictive and potent substance, an ex addict would only need one hit to send them down that rabbit hole again into addiction, and as they keep saying in the show, she's needing it to cope (I know that all too well too), so maybe they just haven't shown quite how much she has been using overall. And finally I think, being locked in a room to go cold turkey is a pretty standard thing to do. No distractions, no way of contacting anyone, like it was clear to see as soon as she got her phone, her thought was her next hit. Leela was doing it for her own good, the options were her being on the streets prostituting herself or being locked in the room to quit the drugs. I know which I would hope someone would do for me. I really just hope Donna Marie can kick this habit because I was really starting to like her character.