Page 116 Complete Your CE Test Online - Click Here Pharmacologic pain relievers Four categories of pain relievers are commonly used to relieve pain (ACPA, 2016): 1. Nonopioids: Aspirin, NSAIDs, acetaminophen. 2. Opioids (also called narcotics): Morphine, codeine, hydrocodone, oxycodone, methadone. Tramadol and tapentadol are not true opioids, but they work similarly to opioids primarily on the same receptors. 3. Adjuvant analgesics: Medications originally used to treat conditions other than pain, but they may help relieve specific pain problems; examples include some antidepressants and anticonvulsants. 4. Other: Medications with no direct pain-relieving properties may also be prescribed as part of a pain management plan. These include medications to treat insomnia, anxiety, depression, and muscle spasms. Nonopioids Nonsteroidal anti-inflammatory drugs NSAIDS are useful for mild to moderate pain. NSAIDS include such drugs as ibuprofen, aspirin, naproxen, and celecoxib. NSAIDs carry the risk of side effects, and patients who take higher doses of NSAIDs for extended periods are most at risk. Side effects of NSAIDS include the following (Solomon, 2015): ● ● Cardiovascular: NSAIDs may increase blood pressure and may increase the risk for heart attack in patients with an increased risk. These patients should use a low dose under a doctor’s supervision or avoid NSAIDs. This does not apply to those patients who are prescribed aspirin to treat or prevent heart attacks or strokes. ● ● Gastrointestinal: Short-term use can cause stomach upset; long- term use can cause ulcers and gastric bleeding. ● ● Liver: Long-term use at high dosages may require testing for toxicity. ● ● Kidney: Use of NSAIDs can affect the kidneys and should be monitored in those with kidney disease. ● ● Tinnitus: Ringing in the ears can occur in those who are taking high doses of aspirin. NSAIDS have a thinning effect on the blood and should be used with caution or avoided in those patients on blood thinners or antiplatelet aggregation drugs (warfarin, clopidogrel) (ACPA, 2016). NSAIDS are useful in multimodal analgesia, as they can reduce the amount of opioids needed by 20% to 50% in some cases (Mugabure Bujedo et al., 2015). NSAIDS are beneficial for the following reasons: ● ● They can be longer acting. ● ● They have less dose variability from individual to individual when compared to opioids. ● ● They do not induce respiratory depression, dependence, or addiction. ● ● They have a lower incidence of paralytic ileus and nausea and vomiting than opioids have. ● ● They do not cause cognitive alterations. Acetaminophen Acetaminophen (Tylenol) can cause liver toxicity even in low doses in those who have liver dysfunction or those who heavily drink alcohol (ACPA, 2016). The dosage of acetaminophen should not exceed 3000 mg per day unless managed by a physician (ACPA). It should be noted that many medications contain acetaminophen that may not be obvious to the patient. The patient should be aware that many medications labeled “APAP” or end in the suffix “–cet” contain acetaminophen. Many medications contain acetaminophen with no indication from the name that the product contains it. Patients should be counseled to be aware of additional acetaminophen intake if it is a component in their prescription medication. Prescription medications containing acetaminophen include Lorcet, Vicodin, Ultracet, Percocet, Roxicet, Midrin, and Tylox. Opioids Opioids are morphine-like substances that occur naturally in the body (endorphins, enkephalins, dynorphins) or can be synthetic or semisynthetic (ACPA, 2016). Opioids act on four types of receptors in various areas - from the cerebral cortex to the spinal cord and peripheral locations - thus offering incomparable analgesic effects (Mugabure Bujedo et al., 2015). Opioids can be given orally, intravenously, subcutaneously, transdermally, or intramuscularly and are the preferred medication to treat acute pain that is moderate to severe (Marks & Rodgers, 2014). Although opioids do not have a roof/ceiling effect (the point at which increasing doses do not result in increased effectiveness), their use is limited by side effects, such as respiratory depression, itching, and nausea (Mugabure Bujedo et al., 2015). Opioids are not the first choice in chronic pain management but are used extensively and effectively in those suffering moderate to severe acute pain (CDC, n.d.). Following are some commonly used opioid medications for patients presenting in the emergency room (Samcam & Papa, 2016): ● ● Morphine: A commonly used pain reliever for patients presenting to the emergency room with moderate to severe pain. ● ● Hydromorphone: A semisynthetic morphine derivative 7 times more potent than morphine. ● ● Fentanyl: Used in cases where quick pain relief is needed, such as in trauma patients or those with traumatic brain injury. It has less of an effect on blood pressure and can be used in those who cannot tolerate hypotension. Opioids can cause many side effects - constipation, nausea, vomiting, drowsiness, slow reflexes, respiratory depression (see Box 1). According to the Joint Commission (2012), opioid analgesics are frequently involved in adverse events, including wrong dose medication errors, insufficient monitoring of the patient on opioid medication, medication interactions, excessive dosing, and drug reactions. The rule of thumb is start “low and slow” with administering opioids (CDC, n.d.). Self-assessment question 7 Which of the following statements about opioids is FALSE? a. Opioids are not the first step in the treatment of chronic pain states. b. Opioids are the preferred medication for acute moderate to severe pain. c. Hydromorphone is a morphine derivative that is 2 times more potent than morphine. d. Opioids do not have a roof effect. Opioid-induced hyperalgesia Opioid-induced hyperalgesia (OIH) is a complication in some patients receiving opioid therapy. OIH is a form of pain sensitization that results from taking an opioid medication but, unlike tolerance, pain increases with higher doses and decreases with lower doses or discontinuation of the opioid medication (Silverman, 2009). OIH can be difficult to differentiate from pain worsening from disease progression or increased pain from increased activity. But OIH pain is usually more widespread and less defined than pre-existing pain (Silverman, 2009). Methadone, buprenorphine, and ketamine have been used in the treatment of OIH (Silverman). Opioid-induced respiratory depression Nurses need to be aware of the sedating effect of opioids and the possibility of respiratory depression. Typically, respiratory rates < 8 to 10 breaths per minute, decreased SpO2 levels, or elevated end-tidal carbon dioxide (ETCO2) levels indicate opioid-induced respiratory depression (Jarzyna et al., 2011).