I have been taking a daily dosage of 160 mg. of oxicontin and 30 mg of
oxycodone HCL for 4 years and will probably need to take it for the
rest of my life.  What are the adverse effects of longterm oxicontin
usage?

Hi there -

As far as I can tell, the main known long-term adverse effects are the
likelihood of dependence on the drug (this is different from addiction
because dependence is purely physical while addiction has a
psychological component, according to what I've read) and a
possibility of building up a tolerance to the drug.

This is different from short term effects (including drowsiness,
constipation, and difficulty breathing) and the effects of overdose
(mainly respiratory problems).

Here are some websites that discuss the long-term effects of
oxycodone/oxycontin (they are the same thing; OxyContin is a brand
name).

National Institute on Drug Abuse: Research Report Series -
Prescription Drugs: Abuse and Addiction
http://www.nida.nih.gov/ResearchReports/Prescription/prescription8.html 

U.S. Food and Drug Administration Center for Drug Evaluation and
Research: OxyContin: Questions and Answers
http://www.fda.gov/cder/drug/infopage/oxycontin/oxycontin-qa.htm

Mayo Clinic: Opioids (narcotics)
http://www.mayoclinic.com/invoke.cfm?id=PN00042

Mayo Clinic: Pain Pills: Avoiding Addiction
http://www.mayoclinic.com/invoke.cfm?id=PN00056

U.S. FDA: Managing Chronic Pain
http://www.fda.gov/fdac/features/2004/204_pain.html
(Not actually about the effects of OxyContin per se, but an
interesting article about managing long-term, chronic pain with opioid
drugs)

The online drug guides MedMaster and USPDI: Advice for the Patient
also have infromation on OxyContin/Oxycodone:

MedMaster: Oxycodone
http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682132.html

USPDI: Narcotic Analgesics  For Pain Relief (Systemic)
http://www.nlm.nih.gov/medlineplus/druginfo/uspdi/202390.html

I found all of these sites using the MedlinePlus consumer health
system from the National Library of Medicine (www.medlineplus.gov). 
That system has "health topics" that index websites with trustworthy
information.  The topic for Prescription Drug Abuse
(http://www.nlm.nih.gov/medlineplus/prescriptiondrugabuse.html) was
particularly helpful.  The drug guides are also available from
MedlinePlus.

Please let me know if you need more information about
OxyContin/oxycodone and I will do what I can!

Librariankt

You might find the new book _PainKiller_ interesting: 
http://www.amazon.com/exec/obidos/ASIN/1579546382/qid=1087732140/sr=ka-1/ref=pd_ka_1/104-7345210-1092751
-- it is a highly critical examination of the pharmaceutical company's
marketing of potent medication for chronic, nonmalignant pain.

I wouldn't suggest buying it -- as some Amazon reviewers have noted,
it's really an essay padded out to book length, but do skim through it
if your local library has it.

As far as taking oxycodone goes, if you are on the dosing schedule
noted above, you are most likely already physically addicted to it; if
you stop taking it or miss 2 or 3 days of pills, you will go through
withdrawal every bit as bad as that experienced by an intravenous
heroin user -- pray that a natural disaster or act of war never
interferes with your ability to procure your meds.  [I'm a chronic
pain patient myself and am quite sympathetic to your situation; I wish
the myth that people who take opiates for real pain won't get addicted
were true.]

Oxycontin and Oxycodone are the same thing. Also, they should never be
prescribed for long-term pain. Rather, tramadol or antidepressents
should be used.