Here's a brief answer to your questions. I know Shore will elaborate more on your post. Oxycodone is the active ingredient in the roxicet you were taking. The 5 refers to the oxycodone, the 325 refers to the tylenol (APAP). All opiates are compared to morphine when taling of strength (not because morphine is stronger than others, but it is simply the gold standard) Oxycodone is similiar to morphine in that it is derived from opium. Oxycodone is aproximately 1.5 times as strong as oral morphine, hence 10 mg of oxy would equal 15 mg of morphine (these are just general guidlines and personal efficacy varies greatly from one person to the next). Now hydrocodone is also similar to morphine and oxy. hydro is the same strength as oral morphine mg for mg. so 10 mg of oral morphine is the same as 10 mg of hydrocodone in strength. Darvocet is made from propoxyphene and APAP. Propoxyphene is a synthetic narcotic whcih is much weaker than morphine, oxy, and hydro. It would take about 8 to 10 times as much propoxyphene to equal morphine. So 10 mg of morphine would equal between 80 and 100 mg of propoxyphene. When you consider oxy is 1.5 times stronger than morphine, propoxyphene is very weak. In addition the apap in darvocet is dangerous in large doses, and 8 darvocet at 650 mg apap (i'm guessing) is about 5,000 mg of apap, a dangerous dose. You should not exceed 4,000 mg in a 24 hour period of apap. The pain doc likely is shying away from the roxicet because it is a schedule II narcotic, while darvocet is a schedule IV narcotic, much less restricted than CII.