Why is 0xycontin making me sick? I've been taking oxyc0ntin for 10 years but for the last two?

While similar in appearance to the original formulation, the reformulated tablets have a different marking ("OP") than the currently marketed tablets (marking "OC") and the 60 mg and 80 mg tablets are slightly larger in size than the currently marketed tablets.

Purdue elected to reformulate OxyContin® to be bioequivalent to the original formulation and in an effort to make the tablet more difficult to manipulate for the purpose of intentional misuse and abuse, however, there is no evidence that the reformulation of OxyContin is less subject to misuse, abuse, diversion, overdose or addiction.

OxyContin® continues to be a CII controlled substance with all the attendant risks of Schedule II opioids, specifically that the drug has a high potential for abuse. Use, misuse, or abuse of the drug may lead to physical dependence or addiction (addiction is sometimes referred to as "psychological dependence"). In addition, alteration of the tablet in any manner poses significant risks of overdose and death. The Full Prescribing Information contains warnings about the potential for abuse, diversion, overdose and addiction, including a boxed warning (see below).

Indications and Usage
OxyContin® is a controlled-release oral formulation of oxycodone hydrochloride indicated for the management of moderate to severe pain when a continuous, around-the-clock opioid analgesic is needed for an extended period of time.

Limitations of Usage
OxyContin® is not intended for use on an as-needed basis.

As used here, "moderate" and "moderate to severe" pain do not include commonplace and ordinary aches and pains, pulled muscles, cramps, sprains, or similar discomfort.

OxyContin® is not indicated for the management of pain in the immediate postoperative period (the first 12-24 hours following surgery), or if the pain is mild, or not expected to persist for an extended period of time. OxyContin® is indicated for postoperative use following the immediate post-operative period only if the patient is already receiving the drug prior to surgery or if the postoperative pain is expected to be moderate to severe and persist for an extended period of time. Physicians should individualize treatment, moving from parenteral to oral analgesics as appropriate. (See American Pain Society guidelines.)

OxyContin® is not indicated for pre-emptive analgesia (preoperative administration for the management of postoperative pain).

OxyContin® is not indicated for rectal administration.

Important Safety Information
OxyContin® is contraindicated in patients who have significant respiratory depression, patients who have or are suspected of having paralytic ileus, patients who have acute or severe bronchial asthma, and patients who have known hypersensitivity to any of its components or the active ingredient, oxycodone.

Opioid analgesics have a narrow therapeutic index in certain patient populations, especially when combined with CNS depressant drugs, and should be reserved for cases where the benefits of opioid analgesia outweigh the known risks of respiratory depression, altered mental state, and postural hypotension. Use low initial doses of OxyContin® in patients who are not already opioid-tolerant, especially those who are receiving concurrent treatment with muscle relaxants, sedatives, or other CNS active medications.

Serious adverse reactions which may be associated with OxyContin® Tablet therapy in clinical use are respiratory depression, apnea, respiratory arrest, and circulatory depression, hypotension, or shock. The most common adverse reactions (>5%) include: constipation, nausea, somnolence, dizziness, vomiting, pruritus, headache, dry mouth, asthenia, and sweating.

REMS
Working with the FDA, Purdue has developed a Risk Evaluation and Mitigation Strategy (REMS) for OxyContin® Tablets. The OxyContin REMS includes a Medication Guide, Elements to Assure Safe Use, such as healthcare provider training and a timetable for submitting assessments of the REMS.

Product Shipment
The Company expects to begin shipping all dosage strengths of the reformulated product (10 mg, 15 mg, 20 mg, 30 mg, 40 mg, 60 mg and 80 mg) to distributors and pharmacies during the third quarter of 2010, at which time Purdue will cease shipping the original formulation.

"We will work with distributors and pharmacies for a smooth transition to the reformulation that will maintain product supply and protect patient access," said John H. Stewart, President and CEO of Purdue Pharma L.P.

https://www.drugs.com/answers/purdue-pharma-official-statement-re-new-op-323421.html