Patients with chronic pain conditions need to be more keenly aware of how their treatment options might affect them in the long-term due to chronic health issues. Understanding the side effects of different pain killers, including non-opioid alternatives, can help patients better learn what to expect throughout their pain management treatment.
Identifying the Most Common Pain Killers
Prescription pain killers are some of the most heavily prescribed drugs in the world; especially in the US, which ranks highest with 47,580 daily doses of opioids per million people, versus Germany (30,780 doses per million people) and Japan (1,220 doses per million people), which rank second and third respectively. While the opioid crisis is far from a breaking news story, it affects Americans even as the pandemic overwhelmed the healthcare system, and opioid use continues to be an issue today.
Yet despite these worrying numbers, opioids continue to be one of the most effective pain killers known to us. Non-opioid alternatives are essential and continue to be researched. Still, there are cases where opioid pain killers play an irreplaceable role, such as post-surgical pain and intractable pain. Both opioid and non-opioid pain killers play essential roles in pain management for patients with chronic pain conditions. And both have short- and long-term risks and side effects.
Long-Term Side Effects of Opioids
Opioid drugs are a type of pain killer derived or synthesized from opium. While opium has a long history as both a recreational drug and a medical tool, modern prescription pain killers are traced to the discovery of morphine and codeine in the 19th century. Today, the most prescribed opioids are oxycodone, hydrocodone, codeine, and fentanyl. Prescription pain killers are generally prescribed for short periods. They are most effective at addressing severe pain, such as cancer-related pain or post-surgical pain. That being said, people can and do use them for longer than prescribed or are prescribed opioids for a long time. Unlike most drugs listed here, opioids are addictive. Opioid use disorder is the most worrying long-term side effect of prescription pain killers. Others can include:
- Irregular heartbeat
- Increased risk of heart failure
- Constipation problems
- Recurring abdominal pain
- Weakened bones
- Hyperalgesia (increased pain)
- Low mood
Some side effects are only apparent after long-term chronic overuse, such as intestinal perforation and narcotic bowel syndrome. Opioids can be dangerous, but they are especially dangerous if used without a doctor’s explicit instructions.
Long-Term Side Effects of NSAIDs
Non-steroidal anti-inflammatory drugs (NSAIDs) are some of the most commonly prescribed non-opioid over-the-counter pain killers. Ibuprofen and aspirin are the best-known NSAIDs. While opioids block pain receptors in our nerves, NSAIDs help manage pain by temporarily blocking a group of enzymes responsible for producing a chemical in the body involved in inflammation and blood flow processes. While NSAIDs are not good at addressing severe pain, they are better tolerated than opioids, especially for chronic mild-to-moderate pain. But they still have side effects, especially ones associated with regular use. Common NSAID side effects include:
- Gastrointestinal problems (indigestion, nausea, and pain)
- Stomach ulcers
- Increased risk of heart attacks
- Fluid retention
- Skin rashes
- Drug-induced hepatitis (liver disease)
- Kidney problems
Long-Term Side Effects of Acetaminophen
Acetaminophen, paracetamol, or Tylenol is another common over-the-counter pain killer. Unlike NSAIDs, acetaminophen reduces pain by elevating the body’s pain threshold. It is also a useful antipyretic, bringing your temperature down during a fever. Paracetamol is also usually prescribed for mild to moderate pain. It does not affect inflammation. It is often sold as a combination drug with another compound – in fact, more than 600 different combination drugs contain acetaminophen. Long-term use of acetaminophen can put people at risk for:
- Liver damage
- Kidney damage
Non-Analgesic Medication and Pain Management
Some drugs prescribed for pain don’t tackle the issue of reducing pain signals or the sensory perception of pain. These can include muscle relaxants and antidepressants, which can play a role in pain management. Muscle relaxants often help patients with musculoskeletal conditions, especially in cases where cramps and spasms accompany the pain. Antidepressants – particularly modern SSRIs – can help combat the mental aspect of chronic pain and the mental health effects of an injury. Poor mental health, especially low mood and depression can increase pain perception and make physical recovery harder.
Pain management is complex and multifaceted. There are biological, psychological, and even social elements to the perception and origin of pain. While medication is just one modality through which pain can be addressed, many different types of medication affect pain, especially long-term, chronic pain. And any medication taken over long periods will raise questions about side effects. In the case of non-analgesic medicines such as muscle relaxants and antidepressants, the side effects can vary from inconsequential to quite severe.
Using muscle relaxants in concurrence with other pain drugs or for longer than needed can increase the risk of dangerous falls and injuries, especially in older patients. For many patients, muscle relaxants are just as effective in pain relief as Advil, with more adverse effects. Selective serotonin reuptake inhibitors (SSRIs), on the other hand, are a complicated class of drugs with both short-term and long-term effects. Because SSRIs affect the availability of a major neurotransmitter, they can cause emotional numbness, dry mouth, headaches, lower libido, and weight gain.
However, these effects can vary from patient to patient and drug to drug. Among studies researching the efficacy of SSRIs in pain management, at least seven different common types of SSRIs were identified. The research on the long-term effects of SSRI use still leaves a lot to be desired. More time and resources are needed to identify how SSRIs affect the brain and body over multiple years. These drugs are not meant for long-term use in pain management cases. Patients with a chronic pain condition may be prescribed an opioid for episodes of intense pain, but research shows that opioids become less effective at treating pain in the long-term.
Whether a drug will be well-tolerated or not can depend on factors we may have no control over, like genetics. Discussing your options with your doctor or pain management specialist is critical. They may be able to advise you on available pain medication based on your medical and family history, current medications, and concurrent conditions. Finally, while medications play a central role in managing pain symptoms, pain management encompasses a range of modalities, including physical and mental therapy, nerve stimulation, biofeedback, non-invasive interventions, alternative medicine, nutritional changes, and in some cases, surgical intervention.