What is cancer pain?
“Pain” is one of the most common symptoms among cancer patients. Cancer pain could be related to tumor compression, obstruction or metastases. Meanwhile, the patient’s psychological status, such as stress, depression and anxiety, resulting from confronting cancer diagnosis could worsen the feeling of pain.
The principle of pain relief for cancer patients:
The principle of cancer pain relief is offering continuous and effective analgesics, with tolerable side effects, to improve the patient’s quality of life.
- According to The World Health Organization (WHO) Clinical Pain Management Guideline, clinicians should select appropriate analgesics and adjuvant medications based on patients’ severity of pain while pain control. The severity of pain could be divided into three levels: mild, moderate, and severe.
- Mild cancer pain: Administer medications from the first step of the pain management medication ladder. The first choice is to start pain relief with non-opioid analgesics.
- Moderate to severe cancer pain: Administer medications from the second and the third step of the pain management medication ladder to ensure achieving satisfactory pain control. Opioid analgesics are used primarily, and sometimes combining with anticonvulsants, anxiolytics, antidepressants, antiepileptic drugs, muscle relaxants, or steroids. If the pain persists or gets worse, oral or intravenous opiates are added or converted to the equivalent dosage of transdermal patch as needed.
- Appropriate route of administration: Oral administration is the choice of priority.
- Keep the right time or interval of taking medications: To maintain the serum concentration, the patients should take medications continuously and regularly to gain persistent pain control.
The common types of medications for cancer pain:
- Non-opioids: Acetaminophen and Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) (e.g., Celebrex and Naproxen) are most common and effective for mild cancer pain and bone pain.
- Weak opioids: Codeine and Tramadol are useful for mild to moderate cancer pain.
- Strong opioids: For moderate to severe cancer pain, morphine is the drug of choice or can be replaced with an equivalent dosage of Fentanyl transdermal patch as needed.
The common side effects of analgesicss and management:
The side effects below could all be treated and prevented. Therefore, do not worry about taking analgesicss.
- Gastrointestinal (GI) bleeding: Some non-opioids can cause gastrointestinal bleeding. It can be prevented by combining antacids usage.
- Constipation: It is a common side effect of opioids and can be prevented by increasing physical activities, drinking more water, taking high-fiber diet and fruits, or taking stool softeners regularly.
- Nausea and vomiting: They usually happen when taking opioids initially, and would not last longer. Preemptive anti-emetics can be administered.
- Drowsy and Bradypnea (slow breathing): Opioids should be withheld temporarily and keep observation. If symptoms persist, the dosage of analgesicss will be decreased.
- Psychological dependence: It is rarely occur if used correctly as directed by order.
- Allergy: Skin itch and rash may occur and can be relieved by antihistamines.
Precautions in daily living:
- Take medicine regularly and do not stop taking medication by yourself.
- Keep a pain diary: make detail notes about the pain characteristics, location, frequency, and the conditions of taking analgesicss. Discuss with your doctor at follow-up visit and find the most suitable treatment mode.
- To prevent constipation, take foods with rich fibers like vegetables and fruits, drink much more water, do proper exercise, and use stool softeners as prescribed.
- Nausea, vomiting and drowsiness may occur. If no improvement and slow breathing occurs, please seek medical advice immediately.
- Combine other non-pharmacological methods for pain relief, such as relaxation techniques, music therapy, watching TV, those can be distracted to relieve pain.
- Scarborough, B. M., & Smith, C. B. (2018). Optimal pain management for patients with cancer in the modern era. CA: a Cancer Journal for Clinicians, 68(3), 182-196. doi:10.3322/caac.21453
- Swarm, R. A., Paice, J. A., Anghelescu, D. L., Are, M., Bruce, J. Y., Buga, S., ... & Greenlee, H. (2019). Adult cancer pain, version 3.2019, NCCN clinical practice guidelines in oncology. Journal of the National Comprehensive Cancer Network, 17(8), 977-1007. doi:10.6004/jnccn.2019.0038
- World Health Organization. (2018). WHO guidelines for the pharmacological and radiotherapeutic management of cancer pain in adults and adolescents. Retrieved from https://apps.who.int/iris/bitstream/handle/10665/279700/9789241550390-eng.pdf