Short Acting vs. Long Acting Opioids for Chronic Persistent Pain by Masami Hattori, MD
There are three classifications of chronic pain; intermittent, persistent and breakthrough pain.
- Intermittent pain is characterized as episodic and may occur in waves or patterns. Intermittent pain is typically treated with NSAIDS and non-drug therapies, however, intermittent moderate to severe pain may be treated with short-acting opioids.
- Persistent or constant pain is characterized by pain that lasts for 12 or more hours everyday. The pain is usually treated with medicines taken around the clock and with non-drug therapies. Moderate to severe pain may be treated with opioids.
- Breakthrough or sudden pain is characterized by a flare-up or a break through the relief provided by an around the clock pain medicine regime. Short-acting and long-acting opioids may be used together to provide continual relief.
Indications for opioid administration include but are not limited to, moderate to severe pain, significant functional disability and inadequate response to other treatments. For patients with chronic persistent moderate to severe pain, the classic approach is to convert the patient from short-acting opioid to long-acting/sustained release opioid, because long-acting opioids provide less fluctuation in analgesic blood levels, fewer adverse effects, and require less frequent dosing. With new matrixes available, we are seeing more sustained release opioids entering the market. We now have more choices, with medications offering relief from 8 – 72 hours.
In the past, sustained release medication provided relief for only 8 – 12 hours. These include methadone, Oxycontin (oxycodone), MScontin (morphine), and difficult to find levorphanol. The more recent medications provide relief for 12 – 24 hours. These include Kadian (morphine), Avinza (morphine), and Palladone (Hydromorphone). Fentanyl patches use the transdermal approach to introducing medications, providing relief for up to 72 hours.
Which ever sustained relief medications you chose, start with lower doses and slowly titrate these medications to effect. A higher level of caution is required when converting patients from short acting to long acting in opioid naïve patients and elderly. Extreme caution is required for methadone, which takes a very long time to attain the plateau state.
A conversion rate (rough estimate) is:
10 mg hydrocodone = 10 mg oxycodone = 15 mg morphine = 3 mg Hydromorphone = 7 1/2 mcg fentanyl patch = 7 mg methadone
Keep in mind that it is very important to emphasize or reinforce to the patient that they need to take advantage of the opportunity that pain relief brings to make their life better. For most people, this means resuming activities that were stopped by the pain or illness. When opioids are used to eliminate pain without improving lifestyle or function, the medicine becomes the focus of their life and this can do more harm than good.