Questions & explanations
1. What is the WHO analgesic ladder and how do you apply it when only paracetamol and ibuprofen are available?
The WHO analgesic ladder is a stepwise approach to pain management. Step 1 uses non-opioids (paracetamol, NSAIDs) for mild pain. Step 2 adds a weak opioid (like codeine) for moderate pain. Step 3 uses strong opioids (morphine) for severe pain. In low-resource settings with only paracetamol and ibuprofen, you can still follow the ladder: start with both drugs together at maximum safe doses. If pain persists, consider adding an adjuvant like gabapentin or amitriptyline if available. For severe pain, you may need to use the highest doses of available non-opioids and adjuvants, and seek any opioid source (e.g., tramadol). If no opioids exist, non-drug methods and nerve blocks (if possible) become crucial. The ladder's principle of 'by the clock, by the mouth, by the ladder' still applies: give regular doses orally, and move up if pain is not controlled.
2. Compare the advantages and disadvantages of using oral versus injectable pain medicines in a rural clinic with no electricity for refrigeration.
Oral medicines are easier to store (no need for refrigeration), safer to give (no needles), and can be given by family members at home. They are also cheaper and have a lower risk of infection. However, oral drugs may take longer to work (30-60 minutes) and can cause stomach upset. Injectable medicines (like morphine injection) work faster (15-30 minutes) and are useful for severe pain or when the patient cannot swallow. But injectables require sterile needles, syringes, and proper disposal; they need a trained person to give them; and they must be stored in a cool, dry place (some require refrigeration). In a rural clinic without electricity, oral formulations are generally preferred because they are stable at room temperature and easier to manage. If injectables are the only option, use them sparingly and ensure safe disposal of sharps.
3. A patient with bone cancer has severe pain despite high-dose morphine. How can ketamine be added safely?
Ketamine can be added as an intravenous infusion at a low dose, starting at 0.1-0.2 mg/kg per hour. For a 70 kg patient, that is 7-14 mg per hour. It is often given in a hospital setting with monitoring. Before starting, ensure the patient has no uncontrolled high blood pressure or heart disease. Start the infusion and increase slowly every 30-60 minutes until pain relief or side effects occur. Common side effects are sedation, hallucinations, and dissociation (feeling detached). To reduce psychiatric side effects, give a small dose of benzodiazepine (like midazolam) beforehand. The infusion can continue for days to weeks. Oral ketamine (10-50 mg every 6-8 hours) is an option but less studied. Always have naloxone available for opioid overdose, but ketamine does not cause respiratory depression.
4. A patient is using cannabis oil bought online for pain. What potential risks should you discuss?
Risks include unknown quality and dosage: products bought online may contain contaminants like heavy metals or pesticides, and the amount of THC or CBD may not match the label. They can interact with other medicines (e.g., blood thinners like warfarin, increasing bleeding risk). Side effects like dizziness, confusion, and falls are possible, especially in older patients. In some countries, possession is illegal. Smoking cannabis can harm the lungs. There is also a risk of dependence and withdrawal symptoms (irritability, insomnia). I would advise the patient to inform their doctor about all products they use, and to consider using only regulated, pharmaceutical-grade cannabinoids if available. Stopping standard pain medicines in favor of cannabis oil could lead to uncontrolled pain.
5. What are the unique side effects of opioids in children compared to adults?
Children may experience the same side effects as adults (constipation, nausea, drowsiness, itching) but some are more common or different. Constipation is very common and should be prevented with laxatives like polyethylene glycol. Nausea often improves after a few days. Itching (pruritus) is more frequent in children and can be treated with antihistamines like diphenhydramine. Respiratory depression is rare if doses are weight-based and titrated carefully. In neonates and infants, opioids can cause more sedation and feeding difficulties. Children may also develop opioid-induced hyperalgesia (increased sensitivity to pain) with high doses. Always start low and go slow. Monitor for excessive sleepiness or difficulty waking, which may indicate overdose.
6. A patient asks about using medical marijuana for bone pain from cancer. What would you tell them based on current evidence?
Current evidence suggests that cannabinoids may provide mild pain relief for some patients, but they are not as effective as opioids or standard adjuvants. A few studies show that nabiximols (Sativex) can reduce pain in advanced cancer patients who do not get enough relief from opioids. However, side effects like dizziness, drowsiness, and nausea are common. Medical marijuana is not approved in many countries, and its quality and dosage are not standardized. It may help with associated symptoms like poor appetite or insomnia. I would explain that while some patients report benefit, the evidence is not strong, and we should first try proven treatments. If the patient insists, I would advise using only regulated products and starting with low doses.
7. Compare the use of ibuprofen and paracetamol for fever and pain in a child with cancer who has low platelets. Which is safer?
Paracetamol (acetaminophen) is safer for children with low platelets (thrombocytopenia) because it does not affect blood clotting. Ibuprofen (an NSAID) can increase bleeding risk by interfering with platelet function. In cancer patients with low platelets from chemotherapy, avoid NSAIDs like ibuprofen. Paracetamol is the preferred choice for fever and mild pain. The dose for children is 10-15 mg/kg every 4-6 hours, not exceeding 5 doses in 24 hours. Ibuprofen can be used if platelets are normal, but always check with the doctor. For moderate pain, paracetamol combined with a weak opioid (if available) is safer than NSAIDs. Always monitor for signs of bleeding (bruising, nosebleeds) when using any painkiller in a child with low platelets.
8. What are cannabinoids and how are they thought to help cancer pain?
Cannabinoids are chemicals found in the cannabis plant, such as THC (tetrahydrocannabinol) and CBD (cannabidiol). THC is the psychoactive component that causes a 'high,' while CBD is non-psychoactive. They work on cannabinoid receptors (CB1 and CB2) in the brain and immune system, which can reduce pain and inflammation. For cancer pain, they may help with neuropathic pain and improve appetite and sleep. However, evidence is mixed: some studies show modest benefit, while others show no difference from placebo. They are not first-line treatments due to limited evidence and potential side effects like dizziness, drowsiness, and confusion. In some countries, nabiximols (a mouth spray containing THC and CBD) is approved for cancer pain.
9. How can you assess pain in a patient who cannot speak or write, using simple tools?
For patients who cannot speak, use behavioral pain scales that observe facial expressions, body movements, and vocalizations. The PAINAD (Pain Assessment in Advanced Dementia) scale is one example: it scores breathing, negative vocalization, facial expression, body language, and consolability. For children or adults with limited communication, the Wong-Baker FACES scale shows faces from smiling to crying; the patient points to the face that matches their pain. Another simple tool is the numeric rating scale (0-10) where the patient says a number. If the patient cannot use numbers, ask 'no pain, a little pain, a lot of pain' and use a simple 3-point scale. Always ask the caregiver or family who knows the patient's usual behavior.
10. A 5-year-old child with leukemia has mouth sores from chemotherapy. What non-drug methods can reduce pain during eating?
Mouth sores (oral mucositis) cause severe pain. Before meals, give a painkiller like paracetamol or morphine (if prescribed) 30 minutes before eating. Offer soft, bland foods like yogurt, mashed potatoes, or smoothies at room temperature (not hot or cold). Avoid spicy, salty, or acidic foods (like orange juice). Use a straw to bypass sore areas. Rinse the mouth with a saltwater solution (1/2 teaspoon salt in 1 cup water) or a baking soda rinse before and after meals. A topical gel like lidocaine (numbing gel) can be applied to sores 15 minutes before eating, but use sparingly to avoid choking. Keep the mouth moist with ice chips or sugar-free popsicles. Good oral hygiene with a soft toothbrush prevents infection.
11. Why is it important to use age-appropriate pain scales in children, and give an example of a scale for school-age children?
Children at different ages understand pain differently. Using a scale they can grasp ensures accurate pain reporting. For school-age children (6-12 years), the Wong-Baker FACES scale works well: six faces from happy (no pain) to crying (worst pain). The child points to the face that shows how they feel. Another option is the numeric rating scale (0-10) if the child can count. For younger children (3-6 years), the FACES scale is best; for infants, behavioral scales are needed. Using the wrong scale can lead to under- or over-treatment. Always explain the scale in simple words: 'This face is happy because there is no hurt. This face is sad because there is a little hurt. Point to the face that shows how you feel.'
12. A patient with pancreatic cancer has severe burning pain in the upper abdomen that does not respond to morphine. What interventional procedure could help?
For pancreatic cancer pain that is neuropathic (often from celiac plexus invasion), a celiac plexus block can be very effective. This is a procedure where a doctor injects a local anesthetic (like bupivacaine) and sometimes a steroid (like triamcinolone) around the celiac plexus nerves near the pancreas. It can provide significant pain relief for weeks to months. The block is done using ultrasound or CT guidance. It reduces the need for opioids and their side effects. Risks include bleeding, infection, and temporary diarrhea or low blood pressure. It is best done by a pain specialist. Other interventional options include spinal cord stimulation or intrathecal pumps, but these are less common for cancer.