McKenna's Pharmacology for Nursing, 2e

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P A R T 3  Drugs acting on the immune system

NON-STEROIDAL ANTI-INFLAMMATORY AND RELATED AGENTS Non-steroidal anti-inflammatory drugs (NSAIDs) pro- vide strong anti-inflammatory and analgesic effects without the adverse effects associated with the cortico­ steroids (Table 16.2). Paracetamol ( Dymadon, Panadol ) is a related drug and a widely used agent. It has anti- pyretic and analgesic properties but does not have the anti-inflammatory effects of the salicylates or the NSAIDs. It is discussed in this chapter because it is used for many of the same reasons that NSAIDs are used, and nurses and midwives need to understand the simi- larities and differences of these drugs. N on - steroidal anti - inflammatory drugs The NSAIDs are a drug class that has become one of the most commonly used drug types in Australia and New Zealand. Following unanticipated study results linking drugs in this class to an increased risk of cardiovascu- lar events and death as well as increased bleeding in the GI tract, a black box warning was added to all of these drugs pointing out the cardiovascular and GI risks asso- ciated with taking them. This group of drugs includes propionic acids, acetic acids, fenamates, oxicam derivatives and cyclooxy­ genase-2 inhibitors. The classes are defined by chemical structural differences, but, clinically, the NSAIDs are all-inclusive. See Table 16.2 for a list of these drugs by group, as well as their specific indications. The choice of NSAID depends on personal experience and the person’s response to the drug. A person may have little response to one NSAID and a huge response to another. It may take several trials to determine the drug of choice for any particular person (Box 16.4). Therapeutic actions and indications The anti-inflammatory, analgesic and antipyretic effects of the NSAIDs are largely related to inhibition of prosta­ glandin synthesis (see Figure 16.1). The NSAIDs block two enzymes, known as cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). COX-1 is present in all tissues and seems to be involved in many body func- tions, including blood clotting, protecting the stomach lining, and maintaining sodium and water balance in the kidney. COX-1 turns arachidonic acid into prosta­ glandins as needed in a variety of tissues. COX-2 is active at sites of trauma or injury when more prosta- glandins are needed, but it does not seem to be involved in the other tissue functions. By interfering with this part of the inflammatory reaction, NSAIDs block inflammation before all of the signs and symptoms can develop. Most NSAIDs also block various other func- tions of the prostaglandins, including protection of the

bleeding and gastrointestinal (GI) effects of the drug . ■ ■ Monitor laboratory tests for full blood count (FBC), liver and renal function tests, urinalysis, stool guaiac and clotting times to detect bleeding or other adverse effects of the drug and changes in function that could interfere with drug metabolism and excretion . Implementation with rationale ■ ■ Administer with food if GI upset is severe; provide small, frequent meals to alleviate GI effects . ■ ■ Administer drug as indicated; check all drugs being taken for possible salicylate ingredients; monitor dose to avoid toxic levels . ■ ■ Monitor for severe reactions to avoid problems and provide emergency procedures (gastric lavage, induction of vomiting, administration of charcoal) if they occur. ■ ■ Arrange for supportive care and comfort measures (rest, environmental control) to decrease body temperature or to alleviate inflammation . ■ ■ Ensure that the person is well hydrated during therapy to decrease the risk of toxicity . ■ ■ Provide thorough teaching, including measures to avoid adverse effects and warning signs of problems, as well as proper administration, to increase knowledge about drug therapy and to increase compliance with the drug regimen . ■ ■ Offer support and encouragement to deal with the drug regimen . Evaluation ■ ■ Monitor response to the drug (improvement in condition being treated, relief of signs and symptoms of inflammation). ■ ■ Monitor for adverse effects (GI upset, CNS changes, bleeding). ■ ■ Evaluate the effectiveness of the teaching plan (person can name drug, dosage, adverse effects to watch for, specific measures to avoid adverse effects). ■ ■ Monitor the effectiveness of comfort measures and compliance with the drug regimen.

KEY POINTS

■■ Salicylates block prostaglandin activity, which decreases the inflammatory response and relieves the signs and symptoms of inflammation. ■■ Salicylates can cause GI irritation, eighth cranial nerve stimulation, and salicylism—ringing in the ears, acidosis, nausea, vomiting, diarrhoea, mental confusion and lassitude.