Opioids for Chronic Pain
Learn More About Common Pain Conditions, Their Origins, and Mechanisms
Opioids
Opioids are a class of drugs derived from opium, which occurs naturally in the poppy plant. They act on the central nervous system, producing various effects, particularly pain relief. Due to their effectiveness, opioids are often used to treat moderate to severe pain.
Side Effects and Risks
The use of opioids can lead to side effects, which vary depending on the dosage and individual factors. Common side effects include nausea, constipation, itching, increased sweating, drowsiness, confusion, and, in severe cases, respiratory depression. Therefore, opioids should only be used under medical supervision. Opioids can lead to physical dependence, and uncontrolled use can result in psychological dependence or addiction. Patient-specific factors, such as age, comorbidities, concurrent medications, pre-existing substance use disorders, and psychiatric comorbidities, can significantly increase these risks. Before starting opioid therapy, a detailed medical assessment of the benefits and risks is always required to avoid serious complications.
Indication Criteria
National and international guidelines distinguish between the medical use of opioids for cancer-related and non-cancer-related pain. Chronic non-cancer pain should, whenever possible, not be treated with opioids. Scientific evidence suggests that opioids are not more effective than other pain medications for chronic non-cancer pain. Therefore, other therapeutic measures should have been tried or at least considered before starting opioid therapy.
According to the German AWMF guidelines on the use of opioids for non-cancer pain, opioid therapy may be considered for the following conditions:
- Pain in diabetic polyneuropathy
- Pain after shingles / postherpetic neuralgia
- Chronic osteoarthritis pain
- Chronic back pain
- Phantom pain
- Chronic pain after spinal cord injury
- Chronic pain due to nerve root damage
- Chronic pain in rheumatoid arthritis
- The duration of treatment should ideally be limited to 4 to 12 weeks. During this period, other therapeutic options should be evaluated and attempted so that opioids can be discontinued later. Opioid therapy should only be continued beyond 12 weeks if there is a clear, significant reduction in pain.
There are also clear recommendations on when opioids should not be used:
- Headaches (migraines, tension headaches)
- Chronic pelvic pain in women
- Irritable bowel syndrome
- Fibromyalgia syndrome
- Chronic inflammatory bowel diseases
- Chronic pancreatitis
- Various psychiatric disorders
Unwanted Effects of Long-Term Use
Long-term opioid use can lead to the following unwanted effects:
- Loss of sexual desire
- Impotence
- Menstrual irregularities
- Increased overall mortality
- Passivity / lack of drive
- Memory impairment
- Increased risk of falls
- Dependence and Addiction
Opioids lead to physical dependence. When used correctly with proper indication and dosage, along with regular medical reevaluation, the risk of addiction is low. However, in cases of questionable indication and uncontrolled use, there is a significant risk of developing psychological dependence or addiction.
Discontinuation of Opioid Therapy
Opioid therapy should be periodically reevaluated and conducted only under regular medical supervision. If there is no clear benefit, the treatment should be strongly reconsidered, and a gradual reduction and cessation of opioids should be pursued. In cases of doubt, an outpatient intravenous opioid test can help decide whether to continue the treatment.