McKenna's Pharmacology for Nursing, 2e

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P A R T 2  Chemotherapeutic agents

vomiting, diarrhoea, anorexia, abdominal pain and flatulence. Pseudomembranous colitis—a potentially dangerous disorder—has also been reported with some cephalosporins. A particular drug should be discontin- ued immediately at any sign of violent, bloody diarrhoea or abdominal pain. CNS symptoms include headache, dizziness, lethargy and paraesthesias. Nephrotoxicity is also asso- ciated with the use of cephalosporins, most particularly in people who have a predisposing renal insufficiency. Other adverse effects include superinfections, which occur frequently because of the death of protective bacteria of the normal flora. Monitor people receiving parenteral cephalosporins for the possibility of phlebitis with IV administration or local abscess at the site of an IM injection. Clinically important drug–drug interactions Concurrent administration of cephalosporins with aminoglycosides increases the risk for nephrotoxicity. Frequently monitor people receiving this combination, and evaluate serum blood urea nitrogen (BUN) and creatinine levels. People who receive oral anticoagulants in addition to cephalosporins may experience increased bleeding. Teach these people how to monitor for blood loss (e.g. bleeding gums, easy bruising) and to be aware that the dose of the oral anticoagulant may need to be reduced. Instruct the person receiving cephalosporins to avoid alcohol for up to 72 hours after discontinua- tion of the drug to prevent a disulfiram-like reaction, which results in unpleasant symptoms such as flushing, throbbing headache, nausea and vomiting, chest pain, palpitations, dyspnoea, syncope, vertigo, blurred vision and, in extreme reactions, cardiovascular collapse, con- vulsions or even death. Prototype summary: Cefaclor Indications: Treatment of respiratory, dermatological, urinary tract and middle ear infections caused by susceptible strains of bacteria. Actions: Inhibits the synthesis of bacterial cell walls, causing cell death in susceptible bacteria. Pharmacokinetics: Route Peak Duration Oral 30–60 minutes 8–10 hours T 1/2 : 30 to 60 minutes; excreted unchanged in the urine. Adverse effects: Nausea, vomiting, diarrhoea, rash, superinfection, bone marrow depression, risk for pseudomembranous colitis.

Care considerations for people receiving cephalosporins

Assessment: History and examination

■ ■ Assess for possible contraindications or cautions : known allergy to any cephalosporin, penicillin or any other allergens because cross-sensitivity often occurs (obtain specific information about the nature and occurrence of the allergic reactions); history of renal disease, which could exacerbate nephrotoxicity related to the cephalosporin ; and current pregnancy or breastfeeding status. ■ ■ Perform physical assessment to establish baseline data for assessing the effectiveness of the drug and the occurrence of any adverse effects associated with drug therapy. ■ ■ Examine the skin for any rash or lesions, examine injection sites for abscess formation and note respiratory status—including rate, depth and adventitious sounds— to provide a baseline for determining adverse reactions. ■ ■ Perform culture and sensitivity tests at the site of infection. ■ ■ Check renal function test results, including BUN and creatinine clearance, to assess the status of renal functioning and to detect the possible need to alter dose. Implementation with rationale ■ ■ Check culture and sensitivity reports to ensure that this is the drug of choice for this person. ■ ■ Monitor renal function test values before and periodically during therapy to arrange for appropriate dose reduction as needed. ■ ■ Ensure that person receives the full course of the cephalosporin as prescribed, divided around the clock to increase effectiveness and to decrease the risk of development of resistant strains. ■ ■ Monitor the infection site and presenting signs and symptoms (e.g. fever, lethargy) throughout the course of drug therapy. Failure of these signs and symptoms to resolve may indicate the need to reculture the site. Arrange to continue drug therapy for at least 2 days after the resolution of all signs and symptoms to help prevent the development of resistant strains of bacteria. ■ ■ Provide small, frequent meals as tolerated, frequent mouth care and ice chips or sugarless lollies to suck if stomatitis and sore mouth are problems to relieve discomfort and provide nutrition . ■ ■ Provide adequate fluids to replace fluid lost with diarrhoea . ■ ■ Monitor the person for any signs of superinfection to arrange for treatment if superinfection occurs.