(RxWiki News) The decision on when to stop taking pain medication after a surgery is often affected by factors beyond pain intensity. For many with depression or addiction, the line of recovery can be especially blurred.
A recent study investigated factors that contribute to long term use of pain medication after surgery.
The study found that use of pain medication prior to surgery, depression and an individual’s belief that they are at risk of addiction were associated with prolonged opioid use.
"Use pain medication only as directed by your doctor"
Ian Carroll, MD, MS of the Department of Anesthesia at Stanford University in Palo Alto, California and team conducted a study of 109 patients undergoing mastectomy, lumpectomy, thoracotomy, total knee replacement or total hip replacement.
Before surgery, study participants completed questionnaires to determine pain, existing use of opioid pain medication, risk of medication misuse and emotional and mental health.
The questionnaires assessed pain levels specific to the surgery and in other places in the body not related to the surgery. Existing opioid use was classified as either legitimate or illicit, depending on whether the medication was properly prescribed and used as intended.
The risk of medication misuse was established by assessing the participants existing attitudes and fears toward opioids. Past substance use was also evaluated.
Depressive symptoms, post traumatic stress disorder, anxiety, general fear and fear of pain were also measured.
Patients were either prescribed pain medication or instructed to use over the counter medicines. They were told to use the medication for pain and to stop taking the medicine when they no longer had pain.
Pain levels and opioid use was recorded every day after the surgery until the patient reported five consecutive days without pain or medication use.
Six percent of patients were still taking pain medication six months after surgery.
Prescribed opioid use before surgery, depression and a self rated risk of addiction were associated with prolonged opioid use. These factors predicted long-term opioid use better than pain levels or duration.
Those who used opioids before surgery for pain relief were 73 percent more likely to still be using medication at follow-up.
The more depressed a patient was, the more likely they were to have prolonged opioid use.
There was a 42 percent increase in prolonged use risk for every ten point increase on the Beck Depression Inventory, the scale used to measure depression. The scale consisted of 21 questions, each answer being scored on a scale value of zero to three.
Each one point increase on a four point scale of self-rated addiction risk increased the long-term opioid use risk by 53 percent.
These results are significant because it suggests a potential risk of opioid misuse among those who undergo surgery. If six percent of the 17.6 million who undergo surgery every year became long-term users, there would be 1.1 million new opioid users each year.
The study was published in the September issue of Anesthesia and Analgesia.
Support for research and authors was provided by the Foundation for Anesthesia Education and Research, the National Institute on Drug Abuse, John and Dodie Rosekrans Pain Research Endowment and Chris Redlich Pain Research Fund.