Page 30 Complete Your CE Test Online - Click Here ● ● What makes the pain better or worse? ● ● Is the pain worse during certain times of the day or night? ● ● Is there breakthrough pain (intense pain that flares up rapidly even when pain medicine is being used)? ● ● Are there other symptoms, such as trouble sleeping, fatigue, depression, or anxiety? ● ● Does pain interfere with activities of daily life, like eating, bathing, or moving around? A scale from 0 to 10 is used to measure how severe the pain is and help the cancer team choose pain medication. The World Health Organization (WHO) Pain Ladder categorizes pain on a three-step scale. ● ● 0 indicates no pain. ● ● 1 to 3 indicates mild pain (step 1). ● ● 4 to 6 indicates moderate pain (step 2). ● ● 7 to 10 indicates severe pain (step 3). The patient’s past and current pain medications, prognosis, comorbidities, nicotine use, alcohol intake, sedatives, personal or family history of substance abuse, and other factors in the patient history may be considered in formulating a plan for pain relief. In some cases, patients with complex histories and needs are referred to pain specialists or palliative care teams. Pain medications are prescribed based on whether the pain is mild, moderate, or severe. Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) may be used to relieve mild pain or given with opioids for moderate to severe pain. The following are commonly used NSAIDS: ● ● Acetaminophen. ● ● Celecoxib. ● ● Diclofenac. ● ● Ibuprofen. ● ● Ketoprofen. ● ● Ketorolac. Patients, especially older patients who are taking acetaminophen or NSAIDs, need to be closely watched for side effects. The NCCN recommends that patients older than 60 are at high risk of renal toxicities, as are those with preexisting renal abnormalities or taking nephrotoxic drugs. NSAIDs can worsen or cause hypertension, bleeding, gastric upset, nausea, liver function abnormalities, bleeding complications, and congestive heart failure, especially in high-risk groups. Opioids are used to relieve moderate to severe pain. Opioids work to relieve moderate to severe pain, step 2 on the WHO scale. Some patients with cancer pain cease receiving pain relief from opioids after a time because of tolerance. Larger doses or a different opioid may be needed if this happens. Tolerance of an opioid reflects physical dependence, and is not the same as addiction (psychological dependence, in which the patient takes a drug for its euphoric effects). Opioid doses can be safely increased as needed for pain without causing addiction. There are several types of opioids: ● ● Buprenorphine. ● ● Codeine. ● ● Diamorphine. ● ● Fentanyl. ● ● Hydrocodone. ● ● Hydromorphone. ● ● Methadone. ● ● Morphine (the most commonly used opioid for cancer pain). ● ● Oxycodone. ● ● Oxymorphone. ● ● Tapentadol. ● ● Tramadol. Methadone is safer for patients with renal failure and is preferred for those with known opioid allergies because it is synthetic. However, methadone also has disadvantages, including drug interactions, the risk of QT prolongation (an EKG is recommended before starting and two to four weeks after starting treatment), and a variable equianalgesic ratio, making rotation (opioid switching) more challenging. Methadone is metabolized by CYP 3A and CYP 2D6. CYP 3A inducers, (e.g., certain anticonvulsants and antiretroviral agents) can potentially reduce analgesic effect. These are just some of the reasons why it should be prescribed only by experienced clinicians. Codeine requires metabolism by CYP 2D6 into its active form. People with low CYP 2D6 activity may get poor relief from codeine, but people with high CYP 2D6 activity are rapid metabolizers who can quickly reach toxicity with normal doses. Patients started on codeine should be monitored for pain relief and toxicity until effects are assured. Meperidine is notably missing from this list because it has a neurotoxic and cardiotoxic metabolite, normeperidine, with a long half-life, and cancer pain requires repeat dosing over time. Thus it is contraindicated for chronic pain. Butorphanol and pentazocine are mixed agonist-antagonist drugs and are also not recommended for treating cancer pain because switching from a pure opioid agonist drug could precipitate withdrawal crisis and subsequent difficulty getting pain back under control. Most patients with cancer pain will need to receive opioids on a regular schedule. Receiving opioids on a regular schedule helps control the pain. The dose interval depends on which opioid is being used and occurrence of breakthrough pain. The dose is slowly adjusted until there is a good balance between pain relief and side effects. Outpatients and their family caregivers must know how to safely use, store, and dispose of opioids. The following are the most common side effects: ● ● Constipation. ● ● Nausea. ● ● Drowsiness. ● ● Dry mouth. Drowsiness and nausea most often occur when opioid treatment is first started; these patients usually become better within a few days. Other side effects of opioid treatment include the following: ● ● Vomiting. ● ● Hypotension. ● ● Dizziness. ● ● Insomnia. ● ● Confusion. ● ● Delirium or hallucinations. ● ● Trouble urinating. ● ● Problems with breathing. ● ● Severe itching. ● ● Problems with sexual function. ● ● Hot flashes. ● ● Depression. ● ● Hypoglycemia. Teach the patient and family what to watch for and report. Bothersome or severe side effects may require a decreased opioid dose, change to a different opioid, or change in route to help decrease the side effects. Vomiting occurs in about one-third of patients who take opioids; twice as many have nausea. Antiemetics, such as metoclopramide, may be used preventively; prochlorperazine, promethazine, and olanzapine can be used as well. Constipation is common, and a scheduled stimulant laxative is typically started along with opioid treatment unless there is a problem with bowel obstruction or diarrhea, along with encouragement to exercise and take in sufficient fiber. The goal is one bowel movement per day, and the regimen may need to be changed to meet that. Significant respiratory depression can usually be avoided through careful titration of doses. Delirium is linked to opioids but is usually multifactorial and not caused by the opioid. In the event of uncontrolled pain at maximal doses, or neurotoxicity – such as myoclonus, hallucinations, vivid dreams, confusion, or tolerance (less pain relief with the same dose over time), opioid rotation (switching) – may be helpful. Adjuvant drugs may be given along with opioids to optimize pain relief. These drugs can potentiate opioids, help with symptoms, or relieve certain types of pain: ● ● Antidepressants (such as venlafaxine, duloxetine, desipramine, nortriptyline) for neuropathic pain. ● ● Anticonvulsants may also help neuropathic pain.