We can help, but we don't have quite enough info.
You told us you were taking 5/15 of the IR per day, and then mentioned 75/day, so I'm assuming you have always taken the maximum dose, every time? I had to look it up, and it looked as though the patient could take anywhere between 5 and 15 with each dose. As a sidenote, have you ever thought about taking a smaller dose on a more frequent schedule so you don't have the roller coaster effect? Anyway, I'm then assuming you got a script of Q 30 of the 10 mg OxyContin.
But when you say "he gave me a partial script" of the IR, what does that mean? Does he know you take 15 each time? Normally, with these scripts, it's only the first number that's the opiate, and then the second number is something like mg of aspirin or Tylenol. But in your case it looks as though something different is happening.
OxyContin is basically a 24-hour pill, so it releases the pain medication into your system slowly all throughout the day and night. THAT is what stops the roller coaster of up and down.
The up and down you're experiencing is that your IR starts to wear off until you're in legitimate pain, then you take the IR, and I don't know how "immediate" immediate release is, but there's the part of the roller coaster where it's climbing higher and higher until it reaches its' peak. So you've gone from one peak from the previous dose way down until the next dose reaches its' peak. OxyContin is meant to sit there in the background and stay at peak levels all day long, so you're not all over the place.
If and only if we were talking hypothetically, and you were taking 5 mg of the IR, brcause OxyContin is 10mg, and you were taking a quantity of FIVE per day of the 5mg that sent you on the rollercoaster ride, IF IF IF by "partial" you mean that he prescribed THREE per day of the IR, you're getting the same amount as before, just a different route of administration.
5mg x 5 equals 25mg per day
If he took 10mg of that and gave it to you in the extended release form, you now have 10mg + 5mg x 3 equals 25mg per day (same as before). But like I said, you're talking about 15 mg not 5, so I don't really understand how that works.
Your job is to use the IR for breakthrough pain. Despite the 24/7 coverage you will have with your OxyContin, pain will still "break through," and this is when you take an IR.
I sincerely hope this helps a little bit. If you could clarify what he prescribed, maybe we can take another look. Until then, take care. :-) Meggie