McKenna's Pharmacology for Nursing, 2e

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P A R T 3  Drugs acting on the immune system

also known as chrysotherapy , in which gold is taken up by macrophages, which then inhibit phagocytosis; it is reserved for use in people who are unresponsive to conventional therapy and can be very toxic. The gold salts available for use include auranofin ( Ridaura ) and sodium aurothiomalate ( Myocrisin ). Therapeutic actions and indications Chrysotherapy results in inhibition of phagocytosis (see Figure 16.1). Because phagocytosis is blocked, the release of lysosomal enzymes is inhibited and tissue destruction is decreased. This action allows gold salts to suppress and prevent some arthritis and synovitis. Gold salts are indicated to treat selected cases of rheuma- toid and juvenile rheumatoid arthritis in people whose disease has been unresponsive to standard therapy (see Table 16.3 for usual indications). These drugs do not repair damage; they prevent further damage and so are most effective if used early in the disease. Pharmacokinetics The gold salts are absorbed at varying rates, depending on their route of administration. They are widely dis- tributed throughout the body but seem to concentrate in the hypothalamic–pituitary–adrenocortical (HPA) system and in the adrenal and renal cortices. The gold salts are excreted in urine and faeces. These drugs cross the placenta and enter into breast milk. They have been shown to be teratogenic in animal studies and should not be used during pregnancy or breastfeeding. Barrier contraceptives should be recommended to women of childbearing age, and another method of feeding the baby should be used if gold therapy is needed in a breast- feeding woman. Contraindications and cautions Gold salts can be quite toxic and are contraindicated in the presence of any known allergy to gold, uncontrolled diabetes, congestive heart failure, severe debilitation, renal or hepatic impairment, hypertension, blood dyscrasias, recent radiation treatment, history of toxic levels of heavy metals, and pregnancy or breastfeeding. Adverse effects A variety of adverse effects is common with the use of gold salts, which are probably related to their deposition in the tissues and effects at that local level: stomatitis, glossitis, gingivitis, pharyngitis, laryngitis, colitis, diar- rhoea and other GI inflammation; gold bronchitis and interstitial pneumonitis; bone marrow depression; vagi­ nitis and nephrotic syndrome; dermatitis, pruritus and exfoliative dermatitis; and allergic reactions ranging from flushing, fainting and dizziness to anaphylactic shock.

■■ NSAIDs block prostaglandin synthesis at COX-1 and COX-2 sites. This blocks inflammation but also blocks protection of the stomach lining, as well as the kidneys’ regulation of water. ■■ There are many different NSAIDs. If one does not work for a particular person, another one might. ■■ Paracetamol causes vasodilation and heat release, lowering fever and working to relieve pain. ■■ Paracetamol can cause liver failure. It is found in many OTC products. Teach people to avoid toxic doses of paracetamol. ANTIARTHRITIS AGENTS Other drugs that are used to block the inflammatory process include the antiarthritis drugs. Arthritis is a potentially debilitating inflammatory process in the joints that causes pain and bone deformities. Antiarthri- tis drugs include the gold compounds, which are used to prevent and suppress arthritis in selected people with rheumatoid arthritis. The other antiarthritis drugs are specifically used to block the inflammation and tissue damage of rheumatoid arthritis (see Table 16.3). G old compounds Some individuals with rheumatic inflammatory con- ditions do not respond to the usual anti-inflammatory therapies, and their conditions worsen despite weeks or months of standard pharmacological treatment. Some of these individuals respond to treatment with gold salts, Care considerations for people receiving NSAIDs and related agents Assessment: History and examination (Refer to the section on salicylates for implementation with rationale and evaluation.) ■ ■ Assess for contraindications or cautions : known allergies to any salicylates, NSAIDs or tartrazine; pregnancy or breastfeeding; hepatic or renal disease; cardiovascular dysfunction; hypertension; and GI bleeding or peptic ulcer. ■ ■ Assess for baseline status before beginning therapy and for any potential adverse effects : presence of any skin lesions; temperature; orientation, reflexes and affect; pulse, blood pressure and perfusion; respirations and adventitious sounds; liver evaluation; bowel sounds; and FBC, liver and renal function tests, urinalysis, stool guaiac and serum electrolytes. KEY POINTS