Opioids are a family of pain medications chemically related to opium and heroin. They include morphine, fentanyl, codeine, hydromorphone and others. Opioids have unique properties that make them both indispensable for pain management and extremely dangerous.
Unlike virtually any other family of medications, opioids have no maximum effective dose. If any dose, no matter how high, is ineffective at controlling pain, a higher dose can give more pain relief. Most other medications don’t work this way. For example, if 800mg of ibuprofen doesn’t bring relief, it’s very unlikely that any higher dose will. This property makes opioids a mainstay for treating severe acute pain, such as from fractures or after surgery.
But the risks and side-effects are substantial. Tolerance (diminished effectiveness with repeated use) is a common problem requiring dose escalation to maintain the same pain relief. Withdrawal symptoms are miserable (but not dangerous) and addiction is very common. The most serious risk is that opioids decrease the drive to breathe. In patients who are dying and short of breath, this is a welcome benefit, not a side effect. Opioids are essential in hospice care because of their ability to eliminate the sense of shortness of breath. But that same effect in an overdose can stop breathing entirely. Philip Seymour Hoffman is only the most recent well-known victim of this property of opioids.
When I did my residency in the mid-90s the philosophy I was taught about opioids was simple. Opioids were for acute pain. If you broke a bone or had a documented kidney stone you could have a prescription that would last a week or so. Patient requests for more prolonged treatment were met with suspicion. The exception was for dying patients. If you had chronic pain form a disease that was going to kill you, you could have all the opioids you wanted. But if you had chronic pain from arthritis, or chronic back pain, or anything else non-fatal, then opioids were simply off the table. You had to make due with other medicines.
Sometime thereafter, we went through a revolution in our attitude. I’m not a pain specialist, so I don’t know if the revolution was supported by any scientific evidence or was simply a change in philosophy. The new teaching was that pain should be treated seriously, and that doctors had been negligent in providing their patients adequate pain relief. Since pain is an entirely subjective experience, there is no test or objective measurement for pain, and the patient’s report of pain should be accepted at face value. The use of opioid analgesics for chronic conditions became acceptable when other options failed.